Migrate macOS 13 to macOS 15 Intel runner

UI refactor

.envrc

@@ -0,0 +1 @@
+use flake

.gitattributes

@@ -1 +1 @@
-gui-src/** linguist-vendored
+src/gui/** linguist-vendored

.github/ISSUE_TEMPLATE/bug_report.md

@@ -11,13 +11,13 @@ assignees: ''
 A clear and concise description of what the bug is and what you expected to happen.
 
 **Used bbox area**
-Please provide your input parameters so we can reproduce the issue. *(For example: 48.133444 11.569462 48.142609 11.584740)*
+Please provide your input parameters (BBOX) so we can reproduce the issue. *(For example: 48.133444 11.569462 48.142609 11.584740)*
 
 **Arnis and Minecraft version**
-Please tell us what version of Arnis and Minecraft you used.
+Please tell us what version of Arnis and Minecraft you used, as well as if you are on Windows, Linux or MacOS.
 
 **Screenshots**
 If applicable, add screenshots to help explain your problem.
 
 **Additional context**
-Add any other context about the problem here. If you used any more custom settings, please provide them here too. If you experienced any issue with the application itself like a crash, please provide the log file which can be found at C:\Users\USERNAME\AppData\Local\com.louisdev.arnis\logs
+Add any other context about the problem here. If you used any more custom settings, please provide them here too. Please provide the log file if possible as well, which can be found at C:\Users\USERNAME\AppData\Local\com.louisdev.arnis\logs

.github/workflows/ci-build.yml

@@ -18,13 +18,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Set up Rust
       uses: dtolnay/rust-toolchain@v1
       with:
         toolchain: stable
-        components: clippy
+        components: clippy, rustfmt
 
     - name: Install Linux dependencies
       run: |
@@ -48,7 +48,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Set up Rust
       uses: dtolnay/rust-toolchain@v1

.github/workflows/pr-benchmark.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up Rust
         uses: dtolnay/rust-toolchain@v1
@@ -43,7 +43,7 @@ jobs:
       - name: Run benchmark command with memory tracking
         id: benchmark
         run: |
-          /usr/bin/time -v ./target/release/arnis --path="./world" --terrain --bbox="48.101470,11.517792,48.168375,11.626968" 2> benchmark_log.txt
+          /usr/bin/time -v ./target/release/arnis --path="./world" --terrain --bbox="48.125768 11.552296 48.148565 11.593838" 2> benchmark_log.txt
           grep "Maximum resident set size" benchmark_log.txt | awk '{print $6}' > peak_mem_kb.txt
           peak_kb=$(cat peak_mem_kb.txt)
           peak_mb=$((peak_kb / 1024))
@@ -65,7 +65,7 @@ jobs:
           seconds=$((duration % 60))
           peak_mem=${{ steps.benchmark.outputs.peak_memory }}
 
-          baseline_time=135
+          baseline_time=30
           diff=$((duration - baseline_time))
           abs_diff=${diff#-}
 
@@ -79,7 +79,7 @@ jobs:
             verdict="🚨 This PR **drastically worsens generation time**."
           fi
 
-          baseline_mem=5865
+          baseline_mem=935
           mem_annotation=""
           if [ "$peak_mem" -gt 2000 ]; then
             mem_diff=$((peak_mem - baseline_mem))
@@ -87,6 +87,8 @@ jobs:
             mem_annotation=" (↗ ${mem_percent}% more)"
           fi
 
+          benchmark_time=$(date -u "+%Y-%m-%d %H:%M:%S UTC")
+
           {
             echo "summary<<EOF"
             echo "⏱️ Benchmark run finished in **${minutes}m ${seconds}s**"
@@ -98,6 +100,8 @@ jobs:
             echo ""
             echo "${verdict}"
             echo ""
+            echo "📅 **Last benchmark:** ${benchmark_time}"
+            echo ""
             echo "_You can retrigger the benchmark by commenting \`retrigger-benchmark\`._"
             echo "EOF"
           } >> "$GITHUB_OUTPUT"
@@ -108,4 +112,4 @@ jobs:
           message: ${{ steps.comment_body.outputs.summary }}
           comment-tag: benchmark-report
         env:
-          GITHUB_TOKEN: ${{ secrets.BENCHMARK_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.BENCHMARK_TOKEN }}

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
             target: x86_64-unknown-linux-gnu
             binary_name: arnis
             asset_name: arnis-linux
-          - os: macos-13  # Intel runner for x86_64 builds
+          - os: macos-15-intel  # Intel runner for x86_64 builds
             target: x86_64-apple-darwin
             binary_name: arnis
             asset_name: arnis-mac-intel
@@ -30,7 +30,7 @@ jobs:
 
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Set up Rust
       uses: dtolnay/rust-toolchain@v1
@@ -87,7 +87,7 @@ jobs:
       shell: powershell
 
     - name: Upload artifact
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: ${{ matrix.os }}-${{ matrix.target }}-build
         path: target/release/${{ matrix.asset_name }}
@@ -97,13 +97,13 @@ jobs:
     runs-on: macos-latest
     steps:
     - name: Download macOS Intel build
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@v7
       with:
-        name: macos-13-x86_64-apple-darwin-build
+        name: macos-15-intel-x86_64-apple-darwin-build
         path: ./intel
 
     - name: Download macOS ARM64 build
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@v7
       with:
         name: macos-latest-aarch64-apple-darwin-build
         path: ./arm64
@@ -114,7 +114,7 @@ jobs:
         chmod +x arnis-mac-universal
 
     - name: Upload universal binary
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: macos-universal-build
         path: arnis-mac-universal
@@ -124,22 +124,22 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
 
     - name: Download Windows build artifact
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@v7
       with:
         name: windows-latest-x86_64-pc-windows-msvc-build
         path: ./builds/windows
 
     - name: Download Linux build artifact
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@v7
       with:
         name: ubuntu-latest-x86_64-unknown-linux-gnu-build
         path: ./builds/linux
 
     - name: Download macOS universal build artifact
-      uses: actions/download-artifact@v4
+      uses: actions/download-artifact@v7
       with:
         name: macos-universal-build
         path: ./builds/macos
@@ -157,4 +157,4 @@ jobs:
           builds/linux/arnis-linux
           builds/macos/arnis-mac-universal
       env:
-        GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}
+        GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}

.gitignore

@@ -1,8 +1,8 @@
 /wiki
+*.mcworld
 
 # Environment files
 .env
-.envrc
 /.direnv
 
 # Build artifacts

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "arnis"
-version = "2.3.0"
+version = "2.4.1"
 edition = "2021"
 description = "Arnis - Generate real life cities in Minecraft"
 homepage = "https://github.com/louis-e/arnis"
@@ -14,40 +14,49 @@ overflow-checks = true
 
 [features]
 default = ["gui"]
-gui = ["tauri", "tauri-plugin-log", "tauri-plugin-shell", "tokio", "rfd", "dirs", "tauri-build"]
+gui = ["tauri", "tauri-plugin-log", "tauri-plugin-shell", "tokio", "rfd", "dirs", "tauri-build", "bedrock"]
+bedrock = ["bedrockrs_level", "bedrockrs_shared", "nbtx", "zip", "byteorder", "vek"]
 
 [build-dependencies]
 tauri-build = {version = "2", optional = true}
 
 [dependencies]
+base64 = "0.22.1"
+byteorder = { version = "1.5", optional = true }
 clap = { version = "4.5", features = ["derive", "env"] }
 colored = "3.0.0"
 dirs = {version = "6.0.0", optional = true }
-fastanvil = "0.31.0"
-fastnbt = "2.5.0"
+fastanvil = "0.32.0"
+fastnbt = "2.6.0"
 flate2 = "1.1"
 fnv = "1.0.7"
 fs2 = "0.4"
-geo = "0.30.0"
+geo = "0.31.0"
 image = "0.25"
 indicatif = "0.17.11"
 itertools = "0.14.0"
 log = "0.4.27"
 once_cell = "1.21.3"
 rand = "0.8.5"
+rand_chacha = "0.3"
 rayon = "1.10.0"
 reqwest = { version = "0.12.15", features = ["blocking", "json"] }
-rfd = { version = "0.15.4", optional = true }
-semver = "1.0.23"
+rfd = { version = "0.16.0", optional = true }
+semver = "1.0.27"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tauri = { version = "2", optional = true }
 tauri-plugin-log = { version = "2.6.0", optional = true }
 tauri-plugin-shell = { version = "2", optional = true }
-tokio = { version = "1.47.0", features = ["full"], optional = true }
+tokio = { version = "1.48.0", features = ["full"], optional = true }
+bedrockrs_level = { git = "https://github.com/bedrock-crustaceans/bedrock-rs", package = "bedrockrs_level", optional = true }
+bedrockrs_shared = { git = "https://github.com/bedrock-crustaceans/bedrock-rs", package = "bedrockrs_shared", optional = true }
+nbtx = { git = "https://github.com/bedrock-crustaceans/nbtx", optional = true }
+vek = { version = "0.17", optional = true }
+zip = { version = "0.6", default-features = false, features = ["deflate"], optional = true }
 
 [target.'cfg(windows)'.dependencies]
 windows = { version = "0.61.1", features = ["Win32_System_Console"] }
 
 [dev-dependencies]
-tempfile = "3.20.0"
+tempfile = "3.23.0"

README.md

@@ -1,17 +1,17 @@
-<img src="https://github.com/louis-e/arnis/blob/main/gitassets/banner.png?raw=true" width="100%" alt="Banner">
+<img src="assets/git/banner.png" width="100%" alt="Banner">
 
 # Arnis [![CI Build Status](https://github.com/louis-e/arnis/actions/workflows/ci-build.yml/badge.svg)](https://github.com/louis-e/arnis/actions) [<img alt="GitHub Release" src="https://img.shields.io/github/v/release/louis-e/arnis" />](https://github.com/louis-e/arnis/releases) [<img alt="GitHub Downloads (all assets, all releases" src="https://img.shields.io/github/downloads/louis-e/arnis/total" />](https://github.com/louis-e/arnis/releases) [![Download here](https://img.shields.io/badge/Download-here-green)](https://github.com/louis-e/arnis/releases) [![Discord](https://img.shields.io/discord/1326192999738249267?label=Discord&color=%237289da)](https://discord.gg/mA2g69Fhxq)
 
-Arnis creates complex and accurate Minecraft Java Edition worlds that reflect real-world geography, topography, and architecture.
+Arnis creates complex and accurate Minecraft Java Edition (1.17+) and Bedrock Edition worlds that reflect real-world geography, topography, and architecture.
 
 This free and open source project is designed to handle large-scale geographic data from the real world and generate detailed Minecraft worlds. The algorithm processes geospatial data from OpenStreetMap as well as elevation data to create an accurate Minecraft representation of terrain and architecture.
 Generate your hometown, big cities, and natural landscapes with ease!
 
-![Minecraft Preview](https://raw.githubusercontent.com/louis-e/arnis/refs/heads/main/gitassets/preview.jpg)
-<i>This Github page is the official project website. Do not download Arnis from any other website.</i>
+![Minecraft Preview](assets/git/preview.jpg)
+<i>This Github page and [arnismc.com](https://arnismc.com) are the only official project websites. Do not download Arnis from any other website.</i>
 
 ## :keyboard: Usage
-<img width="60%" src="https://github.com/louis-e/arnis/blob/main/gitassets/gui.png?raw=true"><br>
+<img width="60%" src="assets/git/gui.png"><br>
 Download the [latest release](https://github.com/louis-e/arnis/releases/) or [compile](#trophy-open-source) the project on your own.
 
 Choose your area on the map using the rectangle tool and select your Minecraft world - then simply click on <i>Start Generation</i>!
@@ -19,7 +19,7 @@ Additionally, you can customize various generation settings, such as world scale
 
 ## 📚 Documentation
 
-<img src="https://github.com/louis-e/arnis/blob/main/gitassets/documentation.png?raw=true" width="100%" alt="Banner">
+<img src="assets/git/documentation.png" width="100%" alt="Banner">
 
 Full documentation is available in the [GitHub Wiki](https://github.com/louis-e/arnis/wiki/), covering topics such as technical explanations, FAQs, contribution guidelines and roadmaps.
 
@@ -34,7 +34,7 @@ Full documentation is available in the [GitHub Wiki](https://github.com/louis-e/
 #### How to contribute
 This project is open source and welcomes contributions from everyone! Whether you're interested in fixing bugs, improving performance, adding new features, or enhancing documentation, your input is valuable. Simply fork the repository, make your changes, and submit a pull request. Please respect the above mentioned key objectives. Contributions of all levels are appreciated, and your efforts help improve this tool for everyone.
 
-Command line Build: ```cargo run --no-default-features -- --terrain --path="C:/YOUR_PATH/.minecraft/saves/worldname" --bbox="min_lng,min_lat,max_lng,max_lat"```<br>
+Command line Build: ```cargo run --no-default-features -- --terrain --path="C:/YOUR_PATH/.minecraft/saves/worldname" --bbox="min_lat,min_lng,max_lat,max_lng"```<br>
 GUI Build: ```cargo run```<br>
 
 After your pull request was merged, I will take care of regularly creating update releases which will include your changes.
@@ -51,7 +51,7 @@ After your pull request was merged, I will take care of regularly creating updat
 
 ## :newspaper: Academic & Press Recognition
 
-<img src="https://github.com/louis-e/arnis/blob/main/gitassets/recognition.png?raw=true" width="100%" alt="Banner">
+<img src="assets/git/recognition.png" width="100%" alt="Banner">
 
 Arnis has been recognized in various academic and press publications after gaining a lot of attention in December 2024.
 
@@ -78,7 +78,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.[^3]
 
-Download Arnis only from the official source (https://github.com/louis-e/arnis/). Every other website providing a download and claiming to be affiliated with the project is unofficial and may be malicious.
+Download Arnis only from the official source https://arnismc.com or https://github.com/louis-e/arnis/. Every other website providing a download and claiming to be affiliated with the project is unofficial and may be malicious.
 
 The logo was made by @nxfx21.
 

flake.lock

@@ -0,0 +1,60 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1755615617,
+        "narHash": "sha256-HMwfAJBdrr8wXAkbGhtcby1zGFvs+StOp19xNsbqdOg=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "20075955deac2583bb12f07151c2df830ef346b4",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixos-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,36 @@
+{
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    {
+      flake-utils,
+      nixpkgs,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        stdenv = if pkgs.stdenv.isLinux then pkgs.stdenvAdapters.useMoldLinker pkgs.stdenv else pkgs.stdenv;
+      in
+      {
+        devShell = pkgs.mkShell.override { inherit stdenv; } {
+          buildInputs = with pkgs; [
+            openssl.dev
+            pkg-config
+            wayland
+            glib
+            gdk-pixbuf
+            pango
+            gtk3
+            libsoup_3.dev
+            webkitgtk_4_1.dev
+          ];
+        };
+      }
+    );
+}

flake/flake.lock

@@ -1,99 +0,0 @@
-{
-  "nodes": {
-    "fenix": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ],
-        "rust-analyzer-src": "rust-analyzer-src"
-      },
-      "locked": {
-        "lastModified": 1724653830,
-        "narHash": "sha256-88f0KK8h6tGIP4Na5RJDKs0S+7WsGGaCGNkLj/bPV3g=",
-        "owner": "nix-community",
-        "repo": "fenix",
-        "rev": "9ecf5e7d800ace001320da8acadd4a3deb872a83",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-community",
-        "repo": "fenix",
-        "type": "github"
-      }
-    },
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1710146030,
-        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "nixpkgs": {
-      "locked": {
-        "lastModified": 1724479785,
-        "narHash": "sha256-pP3Azj5d6M5nmG68Fu4JqZmdGt4S4vqI5f8te+E/FTw=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "d0e1602ddde669d5beb01aec49d71a51937ed7be",
-        "type": "github"
-      },
-      "original": {
-        "id": "nixpkgs",
-        "ref": "nixos-unstable",
-        "type": "indirect"
-      }
-    },
-    "root": {
-      "inputs": {
-        "fenix": "fenix",
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
-      }
-    },
-    "rust-analyzer-src": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1724586512,
-        "narHash": "sha256-mrfwk6nO8N2WtCq3sB2zhd2QN1HMKzeSESzOA6lSsQg=",
-        "owner": "rust-lang",
-        "repo": "rust-analyzer",
-        "rev": "7106cd3be50b2a43c1d9f2787bf22d4369c2b25b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "rust-lang",
-        "ref": "nightly",
-        "repo": "rust-analyzer",
-        "type": "github"
-      }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
-    }
-  },
-  "root": "root",
-  "version": 7
-}

flake/flake.nix

@@ -1,34 +0,0 @@
-{
-  inputs = {
-    fenix = {
-      url = "github:nix-community/fenix";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
-    flake-utils.url = "github:numtide/flake-utils";
-    nixpkgs.url = "nixpkgs/nixos-unstable";
-  };
-
-  outputs = { self, fenix, flake-utils, nixpkgs }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
-        fenixPkgs = (fenix.packages.${system}.stable);
-      in
-      {
-        devShell = pkgs.mkShell
-          {
-            buildInputs = with pkgs; [
-              openssl.dev
-              pkg-config
-              fenixPkgs.toolchain
-              wayland
-              glib
-              gdk-pixbuf
-              pango
-              gtk3
-              libsoup_3.dev
-              webkitgtk_4_1.dev
-            ];
-          };
-      });
-}

src/args.rs

@@ -1,6 +1,6 @@
 use crate::coordinate_system::geographic::LLBBox;
 use clap::Parser;
-use std::path::Path;
+use std::path::PathBuf;
 use std::time::Duration;
 
 /// Command-line arguments parser
@@ -21,7 +21,7 @@ pub struct Args {
 
     /// Path to the Minecraft world (required)
     #[arg(long, value_parser = validate_minecraft_world_path)]
-    pub path: String,
+    pub path: PathBuf,
 
     /// Downloader method (requests/curl/wget) (optional)
     #[arg(long, default_value = "requests")]
@@ -58,14 +58,10 @@ pub struct Args {
     /// Set floodfill timeout (seconds) (optional)
     #[arg(long, value_parser = parse_duration)]
     pub timeout: Option<Duration>,
-
-    /// Spawn point coordinates (lat, lng)
-    #[arg(skip)]
-    pub spawn_point: Option<(f64, f64)>,
 }
 
-fn validate_minecraft_world_path(path: &str) -> Result<String, String> {
-    let mc_world_path = Path::new(path);
+fn validate_minecraft_world_path(path: &str) -> Result<PathBuf, String> {
+    let mc_world_path = PathBuf::from(path);
     if !mc_world_path.exists() {
         return Err(format!("Path does not exist: {path}"));
     }
@@ -76,7 +72,7 @@ fn validate_minecraft_world_path(path: &str) -> Result<String, String> {
     if !region.is_dir() {
         return Err(format!("No Minecraft world found at {region:?}"));
     }
-    Ok(path.to_string())
+    Ok(mc_world_path)
 }
 
 fn parse_duration(arg: &str) -> Result<std::time::Duration, std::num::ParseIntError> {

src/bedrock_block_map.rs

@@ -0,0 +1,849 @@
+//! Bedrock Block Mapping
+//!
+//! This module provides translation between the internal Block representation
+//! and Bedrock Edition block format. Bedrock uses string identifiers with
+//! state properties that differ slightly from Java Edition.
+
+use crate::block_definitions::Block;
+use std::collections::HashMap;
+
+/// Represents a Bedrock block with its identifier and state properties.
+#[derive(Debug, Clone)]
+pub struct BedrockBlock {
+    /// The Bedrock block identifier (e.g., "minecraft:stone")
+    pub name: String,
+    /// Block state properties as key-value pairs
+    pub states: HashMap<String, BedrockBlockStateValue>,
+}
+
+/// Bedrock block state values can be strings, booleans, or integers.
+#[derive(Debug, Clone)]
+pub enum BedrockBlockStateValue {
+    String(String),
+    Bool(bool),
+    Int(i32),
+}
+
+impl BedrockBlock {
+    /// Creates a simple block with no state properties.
+    pub fn simple(name: &str) -> Self {
+        Self {
+            name: format!("minecraft:{name}"),
+            states: HashMap::new(),
+        }
+    }
+
+    /// Creates a block with state properties.
+    pub fn with_states(name: &str, states: Vec<(&str, BedrockBlockStateValue)>) -> Self {
+        let mut state_map = HashMap::new();
+        for (key, value) in states {
+            state_map.insert(key.to_string(), value);
+        }
+        Self {
+            name: format!("minecraft:{name}"),
+            states: state_map,
+        }
+    }
+}
+
+/// Converts an internal Block to a BedrockBlock representation.
+///
+/// This function handles the mapping between Java Edition block names/properties
+/// and their Bedrock Edition equivalents. Many blocks are identical, but some
+/// require translation of property names or values.
+pub fn to_bedrock_block(block: Block) -> BedrockBlock {
+    let java_name = block.name();
+
+    // Most blocks have the same name in both editions
+    // Handle special cases first, then fall back to direct mapping
+    match java_name {
+        // Grass block is just "grass_block" in both editions
+        "grass_block" => BedrockBlock::simple("grass_block"),
+
+        // Short grass is just "short_grass" in Java but "tallgrass" in Bedrock
+        "short_grass" => BedrockBlock::with_states(
+            "tallgrass",
+            vec![(
+                "tall_grass_type",
+                BedrockBlockStateValue::String("tall".to_string()),
+            )],
+        ),
+
+        // Tall grass needs height state
+        "tall_grass" => BedrockBlock::with_states(
+            "double_plant",
+            vec![(
+                "double_plant_type",
+                BedrockBlockStateValue::String("grass".to_string()),
+            )],
+        ),
+
+        // Oak leaves with persistence
+        "oak_leaves" => BedrockBlock::with_states(
+            "leaves",
+            vec![
+                (
+                    "old_leaf_type",
+                    BedrockBlockStateValue::String("oak".to_string()),
+                ),
+                ("persistent_bit", BedrockBlockStateValue::Bool(true)),
+            ],
+        ),
+
+        // Birch leaves with persistence
+        "birch_leaves" => BedrockBlock::with_states(
+            "leaves",
+            vec![
+                (
+                    "old_leaf_type",
+                    BedrockBlockStateValue::String("birch".to_string()),
+                ),
+                ("persistent_bit", BedrockBlockStateValue::Bool(true)),
+            ],
+        ),
+
+        // Oak log with axis (default up_down)
+        "oak_log" => BedrockBlock::with_states(
+            "oak_log",
+            vec![(
+                "pillar_axis",
+                BedrockBlockStateValue::String("y".to_string()),
+            )],
+        ),
+
+        // Birch log with axis
+        "birch_log" => BedrockBlock::with_states(
+            "birch_log",
+            vec![(
+                "pillar_axis",
+                BedrockBlockStateValue::String("y".to_string()),
+            )],
+        ),
+
+        // Spruce log with axis
+        "spruce_log" => BedrockBlock::with_states(
+            "spruce_log",
+            vec![(
+                "pillar_axis",
+                BedrockBlockStateValue::String("y".to_string()),
+            )],
+        ),
+
+        // Stone slab (bottom half by default)
+        "stone_slab" => BedrockBlock::with_states(
+            "stone_block_slab",
+            vec![
+                (
+                    "stone_slab_type",
+                    BedrockBlockStateValue::String("smooth_stone".to_string()),
+                ),
+                ("top_slot_bit", BedrockBlockStateValue::Bool(false)),
+            ],
+        ),
+
+        // Stone brick slab
+        "stone_brick_slab" => BedrockBlock::with_states(
+            "stone_block_slab",
+            vec![
+                (
+                    "stone_slab_type",
+                    BedrockBlockStateValue::String("stone_brick".to_string()),
+                ),
+                ("top_slot_bit", BedrockBlockStateValue::Bool(false)),
+            ],
+        ),
+
+        // Oak slab
+        "oak_slab" => BedrockBlock::with_states(
+            "wooden_slab",
+            vec![
+                (
+                    "wood_type",
+                    BedrockBlockStateValue::String("oak".to_string()),
+                ),
+                ("top_slot_bit", BedrockBlockStateValue::Bool(false)),
+            ],
+        ),
+
+        // Water (flowing by default)
+        "water" => BedrockBlock::with_states(
+            "water",
+            vec![("liquid_depth", BedrockBlockStateValue::Int(0))],
+        ),
+
+        // Rail with shape state
+        "rail" => BedrockBlock::with_states(
+            "rail",
+            vec![("rail_direction", BedrockBlockStateValue::Int(0))],
+        ),
+
+        // Farmland with moisture
+        "farmland" => BedrockBlock::with_states(
+            "farmland",
+            vec![("moisturized_amount", BedrockBlockStateValue::Int(7))],
+        ),
+
+        // Snow layer
+        "snow" => BedrockBlock::with_states(
+            "snow_layer",
+            vec![("height", BedrockBlockStateValue::Int(0))],
+        ),
+
+        // Cobblestone wall
+        "cobblestone_wall" => BedrockBlock::with_states(
+            "cobblestone_wall",
+            vec![(
+                "wall_block_type",
+                BedrockBlockStateValue::String("cobblestone".to_string()),
+            )],
+        ),
+
+        // Andesite wall
+        "andesite_wall" => BedrockBlock::with_states(
+            "cobblestone_wall",
+            vec![(
+                "wall_block_type",
+                BedrockBlockStateValue::String("andesite".to_string()),
+            )],
+        ),
+
+        // Stone brick wall
+        "stone_brick_wall" => BedrockBlock::with_states(
+            "cobblestone_wall",
+            vec![(
+                "wall_block_type",
+                BedrockBlockStateValue::String("stone_brick".to_string()),
+            )],
+        ),
+
+        // Flowers - poppy is just "red_flower" in Bedrock
+        "poppy" => BedrockBlock::with_states(
+            "red_flower",
+            vec![(
+                "flower_type",
+                BedrockBlockStateValue::String("poppy".to_string()),
+            )],
+        ),
+
+        // Dandelion is "yellow_flower" in Bedrock
+        "dandelion" => BedrockBlock::simple("yellow_flower"),
+
+        // Blue orchid
+        "blue_orchid" => BedrockBlock::with_states(
+            "red_flower",
+            vec![(
+                "flower_type",
+                BedrockBlockStateValue::String("orchid".to_string()),
+            )],
+        ),
+
+        // Azure bluet
+        "azure_bluet" => BedrockBlock::with_states(
+            "red_flower",
+            vec![(
+                "flower_type",
+                BedrockBlockStateValue::String("houstonia".to_string()),
+            )],
+        ),
+
+        // Concrete colors (Bedrock uses a single block with color state)
+        "white_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("white".to_string()))],
+        ),
+        "black_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("black".to_string()))],
+        ),
+        "gray_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("gray".to_string()))],
+        ),
+        "light_gray_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("silver".to_string()),
+            )],
+        ),
+        "light_blue_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("light_blue".to_string()),
+            )],
+        ),
+        "cyan_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("cyan".to_string()))],
+        ),
+        "blue_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("blue".to_string()))],
+        ),
+        "purple_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("purple".to_string()),
+            )],
+        ),
+        "magenta_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("magenta".to_string()),
+            )],
+        ),
+        "red_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("red".to_string()))],
+        ),
+        "orange_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("orange".to_string()),
+            )],
+        ),
+        "yellow_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("yellow".to_string()),
+            )],
+        ),
+        "lime_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("lime".to_string()))],
+        ),
+        "brown_concrete" => BedrockBlock::with_states(
+            "concrete",
+            vec![("color", BedrockBlockStateValue::String("brown".to_string()))],
+        ),
+
+        // Terracotta colors
+        "white_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("white".to_string()))],
+        ),
+        "orange_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("orange".to_string()),
+            )],
+        ),
+        "yellow_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("yellow".to_string()),
+            )],
+        ),
+        "light_blue_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("light_blue".to_string()),
+            )],
+        ),
+        "blue_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("blue".to_string()))],
+        ),
+        "gray_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("gray".to_string()))],
+        ),
+        "green_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("green".to_string()))],
+        ),
+        "red_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("red".to_string()))],
+        ),
+        "brown_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("brown".to_string()))],
+        ),
+        "black_terracotta" => BedrockBlock::with_states(
+            "stained_hardened_clay",
+            vec![("color", BedrockBlockStateValue::String("black".to_string()))],
+        ),
+        // Plain terracotta
+        "terracotta" => BedrockBlock::simple("hardened_clay"),
+
+        // Wool colors
+        "white_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![("color", BedrockBlockStateValue::String("white".to_string()))],
+        ),
+        "red_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![("color", BedrockBlockStateValue::String("red".to_string()))],
+        ),
+        "green_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![("color", BedrockBlockStateValue::String("green".to_string()))],
+        ),
+        "brown_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![("color", BedrockBlockStateValue::String("brown".to_string()))],
+        ),
+        "cyan_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![("color", BedrockBlockStateValue::String("cyan".to_string()))],
+        ),
+        "yellow_wool" => BedrockBlock::with_states(
+            "wool",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("yellow".to_string()),
+            )],
+        ),
+
+        // Carpets
+        "white_carpet" => BedrockBlock::with_states(
+            "carpet",
+            vec![("color", BedrockBlockStateValue::String("white".to_string()))],
+        ),
+        "red_carpet" => BedrockBlock::with_states(
+            "carpet",
+            vec![("color", BedrockBlockStateValue::String("red".to_string()))],
+        ),
+
+        // Stained glass
+        "white_stained_glass" => BedrockBlock::with_states(
+            "stained_glass",
+            vec![("color", BedrockBlockStateValue::String("white".to_string()))],
+        ),
+        "gray_stained_glass" => BedrockBlock::with_states(
+            "stained_glass",
+            vec![("color", BedrockBlockStateValue::String("gray".to_string()))],
+        ),
+        "light_gray_stained_glass" => BedrockBlock::with_states(
+            "stained_glass",
+            vec![(
+                "color",
+                BedrockBlockStateValue::String("silver".to_string()),
+            )],
+        ),
+        "brown_stained_glass" => BedrockBlock::with_states(
+            "stained_glass",
+            vec![("color", BedrockBlockStateValue::String("brown".to_string()))],
+        ),
+
+        // Planks - Bedrock uses single "planks" block with wood_type state
+        "oak_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("oak".to_string()),
+            )],
+        ),
+        "spruce_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("spruce".to_string()),
+            )],
+        ),
+        "birch_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("birch".to_string()),
+            )],
+        ),
+        "jungle_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("jungle".to_string()),
+            )],
+        ),
+        "acacia_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("acacia".to_string()),
+            )],
+        ),
+        "dark_oak_planks" => BedrockBlock::with_states(
+            "planks",
+            vec![(
+                "wood_type",
+                BedrockBlockStateValue::String("dark_oak".to_string()),
+            )],
+        ),
+        "crimson_planks" => BedrockBlock::simple("crimson_planks"),
+        "warped_planks" => BedrockBlock::simple("warped_planks"),
+
+        // Stone variants
+        "stone" => BedrockBlock::simple("stone"),
+        "granite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("granite".to_string()),
+            )],
+        ),
+        "polished_granite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("granite_smooth".to_string()),
+            )],
+        ),
+        "diorite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("diorite".to_string()),
+            )],
+        ),
+        "polished_diorite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("diorite_smooth".to_string()),
+            )],
+        ),
+        "andesite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("andesite".to_string()),
+            )],
+        ),
+        "polished_andesite" => BedrockBlock::with_states(
+            "stone",
+            vec![(
+                "stone_type",
+                BedrockBlockStateValue::String("andesite_smooth".to_string()),
+            )],
+        ),
+
+        // Blocks with different names in Bedrock
+        "bricks" => BedrockBlock::simple("brick_block"),
+        "end_stone_bricks" => BedrockBlock::simple("end_bricks"),
+        "nether_bricks" => BedrockBlock::simple("nether_brick"),
+        "red_nether_bricks" => BedrockBlock::simple("red_nether_brick"),
+        "snow_block" => BedrockBlock::simple("snow"),
+        "dirt_path" => BedrockBlock::simple("grass_path"),
+        "dead_bush" => BedrockBlock::simple("deadbush"),
+        "note_block" => BedrockBlock::simple("noteblock"),
+
+        // Oak items mapped to dark_oak in Bedrock (or generic equivalents)
+        "oak_pressure_plate" => BedrockBlock::simple("wooden_pressure_plate"),
+        "oak_door" => BedrockBlock::simple("wooden_door"),
+        "oak_trapdoor" => BedrockBlock::simple("trapdoor"),
+
+        // Bed (Bedrock uses single "bed" block with color state)
+        "red_bed" => BedrockBlock::with_states(
+            "bed",
+            vec![("color", BedrockBlockStateValue::String("red".to_string()))],
+        ),
+
+        // Default: use the same name (works for many blocks)
+        // Log unmapped blocks to help identify missing mappings
+        _ => BedrockBlock::simple(java_name),
+    }
+}
+
+/// Converts an internal Block with optional Java properties to a BedrockBlock.
+///
+/// This function extends `to_bedrock_block` by also handling block-specific properties
+/// like stair facing/shape, slab type, etc. Java property names and values are converted
+/// to their Bedrock equivalents.
+pub fn to_bedrock_block_with_properties(
+    block: Block,
+    java_properties: Option<&fastnbt::Value>,
+) -> BedrockBlock {
+    let java_name = block.name();
+
+    // Extract Java properties as a map if present
+    let props_map = java_properties.and_then(|v| {
+        if let fastnbt::Value::Compound(map) = v {
+            Some(map)
+        } else {
+            None
+        }
+    });
+
+    // Handle stairs with facing/shape properties
+    if java_name.ends_with("_stairs") {
+        return convert_stairs(java_name, props_map);
+    }
+
+    // Handle slabs with type property (top/bottom/double)
+    if java_name.ends_with("_slab") {
+        return convert_slab(java_name, props_map);
+    }
+
+    // Handle logs with axis property
+    if java_name.ends_with("_log") || java_name.ends_with("_wood") {
+        return convert_log(java_name, props_map);
+    }
+
+    // Fall back to basic conversion without properties
+    to_bedrock_block(block)
+}
+
+/// Convert Java stair block to Bedrock format with proper orientation.
+fn convert_stairs(
+    java_name: &str,
+    props: Option<&std::collections::HashMap<String, fastnbt::Value>>,
+) -> BedrockBlock {
+    // Map Java stair names to Bedrock equivalents
+    let bedrock_name = match java_name {
+        "end_stone_brick_stairs" => "end_brick_stairs",
+        _ => java_name, // Most stairs have the same name
+    };
+
+    let mut states = HashMap::new();
+
+    // Convert facing: Java uses "north/south/east/west", Bedrock uses "weirdo_direction" (0-3)
+    // Bedrock: 0=east, 1=west, 2=south, 3=north
+    if let Some(props) = props {
+        if let Some(fastnbt::Value::String(facing)) = props.get("facing") {
+            let direction = match facing.as_str() {
+                "east" => 0,
+                "west" => 1,
+                "south" => 2,
+                "north" => 3,
+                _ => 0,
+            };
+            states.insert(
+                "weirdo_direction".to_string(),
+                BedrockBlockStateValue::Int(direction),
+            );
+        }
+
+        // Convert half: Java uses "top/bottom", Bedrock uses "upside_down_bit"
+        if let Some(fastnbt::Value::String(half)) = props.get("half") {
+            let upside_down = half == "top";
+            states.insert(
+                "upside_down_bit".to_string(),
+                BedrockBlockStateValue::Bool(upside_down),
+            );
+        }
+    }
+
+    // If no properties were set, use defaults
+    if states.is_empty() {
+        states.insert(
+            "weirdo_direction".to_string(),
+            BedrockBlockStateValue::Int(0),
+        );
+        states.insert(
+            "upside_down_bit".to_string(),
+            BedrockBlockStateValue::Bool(false),
+        );
+    }
+
+    BedrockBlock {
+        name: format!("minecraft:{bedrock_name}"),
+        states,
+    }
+}
+
+/// Convert Java slab block to Bedrock format with proper type.
+fn convert_slab(
+    java_name: &str,
+    props: Option<&std::collections::HashMap<String, fastnbt::Value>>,
+) -> BedrockBlock {
+    let mut states = HashMap::new();
+
+    // Convert type: Java uses "top/bottom/double", Bedrock uses "top_slot_bit"
+    if let Some(props) = props {
+        if let Some(fastnbt::Value::String(slab_type)) = props.get("type") {
+            let top_slot = slab_type == "top";
+            states.insert(
+                "top_slot_bit".to_string(),
+                BedrockBlockStateValue::Bool(top_slot),
+            );
+            // Note: "double" slabs in Java become full blocks in Bedrock (different block ID)
+        }
+    }
+
+    // Default to bottom if not specified
+    if !states.contains_key("top_slot_bit") {
+        states.insert(
+            "top_slot_bit".to_string(),
+            BedrockBlockStateValue::Bool(false),
+        );
+    }
+
+    // Handle special slab name mappings (same as in to_bedrock_block)
+    let bedrock_name = match java_name {
+        "stone_slab" => "stone_block_slab",
+        "stone_brick_slab" => "stone_block_slab",
+        "oak_slab" => "wooden_slab",
+        "spruce_slab" => "wooden_slab",
+        "birch_slab" => "wooden_slab",
+        "jungle_slab" => "wooden_slab",
+        "acacia_slab" => "wooden_slab",
+        "dark_oak_slab" => "wooden_slab",
+        _ => java_name,
+    };
+
+    // Add wood_type for wooden slabs
+    if bedrock_name == "wooden_slab" {
+        let wood_type = java_name.trim_end_matches("_slab");
+        states.insert(
+            "wood_type".to_string(),
+            BedrockBlockStateValue::String(wood_type.to_string()),
+        );
+    }
+
+    // Add stone_slab_type for stone slabs
+    if bedrock_name == "stone_block_slab" {
+        let slab_type = if java_name == "stone_brick_slab" {
+            "stone_brick"
+        } else {
+            "stone"
+        };
+        states.insert(
+            "stone_slab_type".to_string(),
+            BedrockBlockStateValue::String(slab_type.to_string()),
+        );
+    }
+
+    BedrockBlock {
+        name: format!("minecraft:{bedrock_name}"),
+        states,
+    }
+}
+
+/// Convert Java log/wood block to Bedrock format with proper axis.
+fn convert_log(
+    java_name: &str,
+    props: Option<&std::collections::HashMap<String, fastnbt::Value>>,
+) -> BedrockBlock {
+    let bedrock_name = java_name;
+    let mut states = HashMap::new();
+
+    // Convert axis: Java uses "x/y/z", Bedrock uses "pillar_axis"
+    if let Some(props) = props {
+        if let Some(fastnbt::Value::String(axis)) = props.get("axis") {
+            states.insert(
+                "pillar_axis".to_string(),
+                BedrockBlockStateValue::String(axis.clone()),
+            );
+        }
+    }
+
+    // Default to y-axis if not specified
+    if states.is_empty() {
+        states.insert(
+            "pillar_axis".to_string(),
+            BedrockBlockStateValue::String("y".to_string()),
+        );
+    }
+
+    BedrockBlock {
+        name: format!("minecraft:{bedrock_name}"),
+        states,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::block_definitions::{AIR, GRASS_BLOCK, STONE};
+
+    #[test]
+    fn test_simple_blocks() {
+        let bedrock = to_bedrock_block(STONE);
+        assert_eq!(bedrock.name, "minecraft:stone");
+        assert!(bedrock.states.is_empty());
+
+        let bedrock = to_bedrock_block(AIR);
+        assert_eq!(bedrock.name, "minecraft:air");
+    }
+
+    #[test]
+    fn test_grass_block() {
+        let bedrock = to_bedrock_block(GRASS_BLOCK);
+        assert_eq!(bedrock.name, "minecraft:grass_block");
+    }
+
+    #[test]
+    fn test_colored_blocks() {
+        use crate::block_definitions::WHITE_CONCRETE;
+        let bedrock = to_bedrock_block(WHITE_CONCRETE);
+        assert_eq!(bedrock.name, "minecraft:concrete");
+        assert!(matches!(
+            bedrock.states.get("color"),
+            Some(BedrockBlockStateValue::String(s)) if s == "white"
+        ));
+    }
+
+    #[test]
+    fn test_stairs_with_properties() {
+        use crate::block_definitions::OAK_STAIRS;
+        use std::collections::HashMap as StdHashMap;
+
+        // Create Java properties for a south-facing stair
+        let mut props = StdHashMap::new();
+        props.insert(
+            "facing".to_string(),
+            fastnbt::Value::String("south".to_string()),
+        );
+        props.insert(
+            "half".to_string(),
+            fastnbt::Value::String("bottom".to_string()),
+        );
+        let java_props = fastnbt::Value::Compound(props);
+
+        let bedrock = to_bedrock_block_with_properties(OAK_STAIRS, Some(&java_props));
+        assert_eq!(bedrock.name, "minecraft:oak_stairs");
+
+        // Check weirdo_direction is set correctly (south = 2)
+        assert!(matches!(
+            bedrock.states.get("weirdo_direction"),
+            Some(BedrockBlockStateValue::Int(2))
+        ));
+
+        // Check upside_down_bit is false for bottom half
+        assert!(matches!(
+            bedrock.states.get("upside_down_bit"),
+            Some(BedrockBlockStateValue::Bool(false))
+        ));
+    }
+
+    #[test]
+    fn test_stairs_upside_down() {
+        use crate::block_definitions::STONE_BRICK_STAIRS;
+        use std::collections::HashMap as StdHashMap;
+
+        // Create Java properties for an upside-down north-facing stair
+        let mut props = StdHashMap::new();
+        props.insert(
+            "facing".to_string(),
+            fastnbt::Value::String("north".to_string()),
+        );
+        props.insert(
+            "half".to_string(),
+            fastnbt::Value::String("top".to_string()),
+        );
+        let java_props = fastnbt::Value::Compound(props);
+
+        let bedrock = to_bedrock_block_with_properties(STONE_BRICK_STAIRS, Some(&java_props));
+
+        // Check weirdo_direction is set correctly (north = 3)
+        assert!(matches!(
+            bedrock.states.get("weirdo_direction"),
+            Some(BedrockBlockStateValue::Int(3))
+        ));
+
+        // Check upside_down_bit is true for top half
+        assert!(matches!(
+            bedrock.states.get("upside_down_bit"),
+            Some(BedrockBlockStateValue::Bool(true))
+        ));
+    }
+}

src/block_definitions.rs

@@ -236,7 +236,7 @@ impl Block {
             155 => "chest",
             156 => "red_carpet",
             157 => "anvil",
-            158 => "jukebox",
+            158 => "note_block",
             159 => "oak_door",
             160 => "brewing_stand",
             161 => "red_bed", // North head
@@ -266,6 +266,7 @@ impl Block {
             185 => "quartz_stairs",
             186 => "polished_andesite_stairs",
             187 => "nether_brick_stairs",
+            188 => "fern",
             _ => panic!("Invalid id"),
         }
     }
@@ -667,7 +668,7 @@ pub const OAK_STAIRS: Block = Block::new(144);
 pub const CHEST: Block = Block::new(155);
 pub const RED_CARPET: Block = Block::new(156);
 pub const ANVIL: Block = Block::new(157);
-pub const JUKEBOX: Block = Block::new(158);
+pub const NOTE_BLOCK: Block = Block::new(158);
 pub const OAK_DOOR: Block = Block::new(159);
 pub const BREWING_STAND: Block = Block::new(160);
 pub const RED_BED_NORTH_HEAD: Block = Block::new(161);
@@ -697,6 +698,7 @@ pub const SMOOTH_SANDSTONE_STAIRS: Block = Block::new(184);
 pub const QUARTZ_STAIRS: Block = Block::new(185);
 pub const POLISHED_ANDESITE_STAIRS: Block = Block::new(186);
 pub const NETHER_BRICK_STAIRS: Block = Block::new(187);
+pub const FERN: Block = Block::new(188);
 
 /// Maps a block to its corresponding stair variant
 #[inline]

src/clipping.rs

@@ -0,0 +1,706 @@
+// Sutherland-Hodgman polygon clipping and related geometry utilities.
+//
+// Provides bbox clipping for polygons, polylines, and water rings with
+// proper corner insertion for closed shapes.
+
+use crate::coordinate_system::cartesian::{XZBBox, XZPoint};
+use crate::osm_parser::ProcessedNode;
+use std::collections::HashMap;
+
+/// Clips a way to the bounding box using Sutherland-Hodgman for polygons or
+/// simple line clipping for polylines. Preserves endpoint IDs for ring assembly.
+pub fn clip_way_to_bbox(nodes: &[ProcessedNode], xzbbox: &XZBBox) -> Vec<ProcessedNode> {
+    if nodes.is_empty() {
+        return Vec::new();
+    }
+
+    let is_closed = is_closed_polygon(nodes);
+
+    if !is_closed {
+        return clip_polyline_to_bbox(nodes, xzbbox);
+    }
+
+    // If all nodes are inside the bbox, return unchanged
+    let has_nodes_outside = nodes
+        .iter()
+        .any(|node| !xzbbox.contains(&XZPoint::new(node.x, node.z)));
+
+    if !has_nodes_outside {
+        return nodes.to_vec();
+    }
+
+    let min_x = xzbbox.min_x() as f64;
+    let min_z = xzbbox.min_z() as f64;
+    let max_x = xzbbox.max_x() as f64;
+    let max_z = xzbbox.max_z() as f64;
+
+    let mut polygon: Vec<(f64, f64)> = nodes.iter().map(|n| (n.x as f64, n.z as f64)).collect();
+
+    polygon = clip_polygon_sutherland_hodgman(polygon, min_x, min_z, max_x, max_z);
+
+    if polygon.len() < 3 {
+        return Vec::new();
+    }
+
+    // Final clamping for floating-point errors
+    for p in &mut polygon {
+        p.0 = p.0.clamp(min_x, max_x);
+        p.1 = p.1.clamp(min_z, max_z);
+    }
+
+    let polygon = remove_consecutive_duplicates(polygon);
+    if polygon.len() < 3 {
+        return Vec::new();
+    }
+
+    let polygon = insert_bbox_corners(polygon, min_x, min_z, max_x, max_z);
+    let polygon = remove_consecutive_duplicates(polygon);
+    if polygon.len() < 3 {
+        return Vec::new();
+    }
+
+    let way_id = nodes.first().map(|n| n.id).unwrap_or(0);
+    assign_node_ids_preserving_endpoints(nodes, polygon, way_id)
+}
+
+/// Clips a water polygon ring to bbox using Sutherland-Hodgman (post-ring-merge).
+pub fn clip_water_ring_to_bbox(
+    ring: &[ProcessedNode],
+    xzbbox: &XZBBox,
+) -> Option<Vec<ProcessedNode>> {
+    if ring.is_empty() {
+        return None;
+    }
+
+    let min_x = xzbbox.min_x() as f64;
+    let min_z = xzbbox.min_z() as f64;
+    let max_x = xzbbox.max_x() as f64;
+    let max_z = xzbbox.max_z() as f64;
+
+    // Check if entire ring is inside bbox
+    let all_inside = ring.iter().all(|n| {
+        n.x as f64 >= min_x && n.x as f64 <= max_x && n.z as f64 >= min_z && n.z as f64 <= max_z
+    });
+
+    if all_inside {
+        return Some(ring.to_vec());
+    }
+
+    // Check if entire ring is outside bbox
+    if is_ring_outside_bbox(ring, min_x, min_z, max_x, max_z) {
+        return None;
+    }
+
+    // Convert to f64 coordinates and ensure closed
+    let mut polygon: Vec<(f64, f64)> = ring.iter().map(|n| (n.x as f64, n.z as f64)).collect();
+    if !polygon.is_empty() && polygon.first() != polygon.last() {
+        polygon.push(polygon[0]);
+    }
+
+    // Clip with full-range clamping (water uses simpler approach)
+    polygon = clip_polygon_sutherland_hodgman_simple(polygon, min_x, min_z, max_x, max_z);
+
+    if polygon.len() < 3 {
+        return None;
+    }
+
+    // Verify all points are within bbox
+    let all_points_inside = polygon
+        .iter()
+        .all(|&(x, z)| x >= min_x && x <= max_x && z >= min_z && z <= max_z);
+
+    if !all_points_inside {
+        eprintln!("ERROR: clip_water_ring_to_bbox produced points outside bbox!");
+        return None;
+    }
+
+    let polygon = insert_bbox_corners(polygon, min_x, min_z, max_x, max_z);
+    if polygon.len() < 3 {
+        return None;
+    }
+
+    // Convert back to ProcessedNode with synthetic IDs
+    let mut result: Vec<ProcessedNode> = polygon
+        .iter()
+        .enumerate()
+        .map(|(i, &(x, z))| ProcessedNode {
+            id: 1_000_000_000 + i as u64,
+            tags: HashMap::new(),
+            x: x.clamp(min_x, max_x).round() as i32,
+            z: z.clamp(min_z, max_z).round() as i32,
+        })
+        .collect();
+
+    // Close the loop by matching first and last ID
+    if !result.is_empty() {
+        let first_id = result[0].id;
+        result.last_mut().unwrap().id = first_id;
+    }
+
+    Some(result)
+}
+
+// ============================================================================
+// Internal helpers
+// ============================================================================
+
+/// Checks if a way forms a closed polygon.
+fn is_closed_polygon(nodes: &[ProcessedNode]) -> bool {
+    if nodes.len() < 3 {
+        return false;
+    }
+    let first = nodes.first().unwrap();
+    let last = nodes.last().unwrap();
+    first.id == last.id || (first.x == last.x && first.z == last.z)
+}
+
+/// Checks if an entire ring is outside the bbox.
+fn is_ring_outside_bbox(
+    ring: &[ProcessedNode],
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> bool {
+    let all_left = ring.iter().all(|n| (n.x as f64) < min_x);
+    let all_right = ring.iter().all(|n| (n.x as f64) > max_x);
+    let all_top = ring.iter().all(|n| (n.z as f64) < min_z);
+    let all_bottom = ring.iter().all(|n| (n.z as f64) > max_z);
+    all_left || all_right || all_top || all_bottom
+}
+
+/// Clips a polyline (open path) to the bounding box.
+fn clip_polyline_to_bbox(nodes: &[ProcessedNode], xzbbox: &XZBBox) -> Vec<ProcessedNode> {
+    if nodes.is_empty() {
+        return Vec::new();
+    }
+
+    let min_x = xzbbox.min_x() as f64;
+    let min_z = xzbbox.min_z() as f64;
+    let max_x = xzbbox.max_x() as f64;
+    let max_z = xzbbox.max_z() as f64;
+
+    let mut result = Vec::new();
+
+    for i in 0..nodes.len() {
+        let current = &nodes[i];
+        let current_point = (current.x as f64, current.z as f64);
+        let current_inside = point_in_bbox(current_point, min_x, min_z, max_x, max_z);
+
+        if current_inside {
+            result.push(current.clone());
+        }
+
+        if i + 1 < nodes.len() {
+            let next = &nodes[i + 1];
+            let next_point = (next.x as f64, next.z as f64);
+            let next_inside = point_in_bbox(next_point, min_x, min_z, max_x, max_z);
+
+            if current_inside != next_inside {
+                // One endpoint inside, one outside, find single intersection
+                let intersections =
+                    find_bbox_intersections(current_point, next_point, min_x, min_z, max_x, max_z);
+
+                for intersection in intersections {
+                    let synthetic_id = nodes[0]
+                        .id
+                        .wrapping_mul(10000000)
+                        .wrapping_add(result.len() as u64);
+                    result.push(ProcessedNode {
+                        id: synthetic_id,
+                        x: intersection.0.round() as i32,
+                        z: intersection.1.round() as i32,
+                        tags: HashMap::new(),
+                    });
+                }
+            } else if !current_inside && !next_inside {
+                // Both endpoints outside, segment might still cross through bbox
+                let mut intersections =
+                    find_bbox_intersections(current_point, next_point, min_x, min_z, max_x, max_z);
+
+                if intersections.len() >= 2 {
+                    // Sort intersections by distance from current point
+                    intersections.sort_by(|a, b| {
+                        let dist_a =
+                            (a.0 - current_point.0).powi(2) + (a.1 - current_point.1).powi(2);
+                        let dist_b =
+                            (b.0 - current_point.0).powi(2) + (b.1 - current_point.1).powi(2);
+                        dist_a
+                            .partial_cmp(&dist_b)
+                            .unwrap_or(std::cmp::Ordering::Equal)
+                    });
+
+                    for intersection in intersections {
+                        let synthetic_id = nodes[0]
+                            .id
+                            .wrapping_mul(10000000)
+                            .wrapping_add(result.len() as u64);
+                        result.push(ProcessedNode {
+                            id: synthetic_id,
+                            x: intersection.0.round() as i32,
+                            z: intersection.1.round() as i32,
+                            tags: HashMap::new(),
+                        });
+                    }
+                }
+            }
+        }
+    }
+
+    // Preserve endpoint IDs where possible
+    if result.len() >= 2 {
+        let tolerance = 50.0;
+        if let Some(first_orig) = nodes.first() {
+            if matches_endpoint(
+                (result[0].x as f64, result[0].z as f64),
+                first_orig,
+                tolerance,
+            ) {
+                result[0].id = first_orig.id;
+            }
+        }
+        if let Some(last_orig) = nodes.last() {
+            let last_idx = result.len() - 1;
+            if matches_endpoint(
+                (result[last_idx].x as f64, result[last_idx].z as f64),
+                last_orig,
+                tolerance,
+            ) {
+                result[last_idx].id = last_orig.id;
+            }
+        }
+    }
+
+    result
+}
+
+/// Sutherland-Hodgman polygon clipping with edge-specific clamping.
+fn clip_polygon_sutherland_hodgman(
+    mut polygon: Vec<(f64, f64)>,
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> Vec<(f64, f64)> {
+    // Edges: bottom, right, top, left (counter-clockwise traversal)
+    let bbox_edges = [
+        (min_x, min_z, max_x, min_z, 0), // Bottom: clamp z
+        (max_x, min_z, max_x, max_z, 1), // Right: clamp x
+        (max_x, max_z, min_x, max_z, 2), // Top: clamp z
+        (min_x, max_z, min_x, min_z, 3), // Left: clamp x
+    ];
+
+    for (edge_x1, edge_z1, edge_x2, edge_z2, edge_idx) in bbox_edges {
+        if polygon.is_empty() {
+            break;
+        }
+
+        let mut clipped = Vec::new();
+        let is_closed = !polygon.is_empty() && polygon.first() == polygon.last();
+        let edge_count = if is_closed {
+            polygon.len().saturating_sub(1)
+        } else {
+            polygon.len()
+        };
+
+        for i in 0..edge_count {
+            let current = polygon[i];
+            let next = polygon.get(i + 1).copied().unwrap_or(polygon[0]);
+
+            let current_inside = point_inside_edge(current, edge_x1, edge_z1, edge_x2, edge_z2);
+            let next_inside = point_inside_edge(next, edge_x1, edge_z1, edge_x2, edge_z2);
+
+            if next_inside {
+                if !current_inside {
+                    if let Some(mut intersection) = line_edge_intersection(
+                        current.0, current.1, next.0, next.1, edge_x1, edge_z1, edge_x2, edge_z2,
+                    ) {
+                        // Clamp to current edge only
+                        match edge_idx {
+                            0 => intersection.1 = min_z,
+                            1 => intersection.0 = max_x,
+                            2 => intersection.1 = max_z,
+                            3 => intersection.0 = min_x,
+                            _ => {}
+                        }
+                        clipped.push(intersection);
+                    }
+                }
+                clipped.push(next);
+            } else if current_inside {
+                if let Some(mut intersection) = line_edge_intersection(
+                    current.0, current.1, next.0, next.1, edge_x1, edge_z1, edge_x2, edge_z2,
+                ) {
+                    match edge_idx {
+                        0 => intersection.1 = min_z,
+                        1 => intersection.0 = max_x,
+                        2 => intersection.1 = max_z,
+                        3 => intersection.0 = min_x,
+                        _ => {}
+                    }
+                    clipped.push(intersection);
+                }
+            }
+        }
+
+        polygon = clipped;
+    }
+
+    polygon
+}
+
+/// Sutherland-Hodgman with full bbox clamping (simpler, for water rings).
+fn clip_polygon_sutherland_hodgman_simple(
+    mut polygon: Vec<(f64, f64)>,
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> Vec<(f64, f64)> {
+    let bbox_edges = [
+        (min_x, min_z, max_x, min_z),
+        (max_x, min_z, max_x, max_z),
+        (max_x, max_z, min_x, max_z),
+        (min_x, max_z, min_x, min_z),
+    ];
+
+    for (edge_x1, edge_z1, edge_x2, edge_z2) in bbox_edges {
+        if polygon.is_empty() {
+            break;
+        }
+
+        let mut clipped = Vec::new();
+
+        for i in 0..(polygon.len().saturating_sub(1)) {
+            let current = polygon[i];
+            let next = polygon[i + 1];
+
+            let current_inside = point_inside_edge(current, edge_x1, edge_z1, edge_x2, edge_z2);
+            let next_inside = point_inside_edge(next, edge_x1, edge_z1, edge_x2, edge_z2);
+
+            if next_inside {
+                if !current_inside {
+                    if let Some(mut intersection) = line_edge_intersection(
+                        current.0, current.1, next.0, next.1, edge_x1, edge_z1, edge_x2, edge_z2,
+                    ) {
+                        intersection.0 = intersection.0.clamp(min_x, max_x);
+                        intersection.1 = intersection.1.clamp(min_z, max_z);
+                        clipped.push(intersection);
+                    }
+                }
+                clipped.push(next);
+            } else if current_inside {
+                if let Some(mut intersection) = line_edge_intersection(
+                    current.0, current.1, next.0, next.1, edge_x1, edge_z1, edge_x2, edge_z2,
+                ) {
+                    intersection.0 = intersection.0.clamp(min_x, max_x);
+                    intersection.1 = intersection.1.clamp(min_z, max_z);
+                    clipped.push(intersection);
+                }
+            }
+        }
+
+        polygon = clipped;
+    }
+
+    polygon
+}
+
+/// Checks if point is inside bbox.
+fn point_in_bbox(point: (f64, f64), min_x: f64, min_z: f64, max_x: f64, max_z: f64) -> bool {
+    point.0 >= min_x && point.0 <= max_x && point.1 >= min_z && point.1 <= max_z
+}
+
+/// Checks if point is on the "inside" side of an edge (cross product test).
+fn point_inside_edge(
+    point: (f64, f64),
+    edge_x1: f64,
+    edge_z1: f64,
+    edge_x2: f64,
+    edge_z2: f64,
+) -> bool {
+    let edge_dx = edge_x2 - edge_x1;
+    let edge_dz = edge_z2 - edge_z1;
+    let point_dx = point.0 - edge_x1;
+    let point_dz = point.1 - edge_z1;
+    (edge_dx * point_dz - edge_dz * point_dx) >= 0.0
+}
+
+/// Finds intersection between a line segment and an edge.
+#[allow(clippy::too_many_arguments)]
+fn line_edge_intersection(
+    line_x1: f64,
+    line_z1: f64,
+    line_x2: f64,
+    line_z2: f64,
+    edge_x1: f64,
+    edge_z1: f64,
+    edge_x2: f64,
+    edge_z2: f64,
+) -> Option<(f64, f64)> {
+    let line_dx = line_x2 - line_x1;
+    let line_dz = line_z2 - line_z1;
+    let edge_dx = edge_x2 - edge_x1;
+    let edge_dz = edge_z2 - edge_z1;
+
+    let denom = line_dx * edge_dz - line_dz * edge_dx;
+    if denom.abs() < 1e-10 {
+        return None;
+    }
+
+    let dx = edge_x1 - line_x1;
+    let dz = edge_z1 - line_z1;
+    let t = (dx * edge_dz - dz * edge_dx) / denom;
+
+    if (0.0..=1.0).contains(&t) {
+        Some((line_x1 + t * line_dx, line_z1 + t * line_dz))
+    } else {
+        None
+    }
+}
+
+/// Finds intersections between a line segment and bbox edges.
+fn find_bbox_intersections(
+    start: (f64, f64),
+    end: (f64, f64),
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> Vec<(f64, f64)> {
+    let mut intersections = Vec::new();
+
+    let bbox_edges = [
+        (min_x, min_z, max_x, min_z),
+        (max_x, min_z, max_x, max_z),
+        (max_x, max_z, min_x, max_z),
+        (min_x, max_z, min_x, min_z),
+    ];
+
+    for (edge_x1, edge_z1, edge_x2, edge_z2) in bbox_edges {
+        if let Some(intersection) = line_edge_intersection(
+            start.0, start.1, end.0, end.1, edge_x1, edge_z1, edge_x2, edge_z2,
+        ) {
+            let on_edge = point_in_bbox(intersection, min_x, min_z, max_x, max_z)
+                && ((intersection.0 == min_x || intersection.0 == max_x)
+                    || (intersection.1 == min_z || intersection.1 == max_z));
+
+            if on_edge {
+                intersections.push(intersection);
+            }
+        }
+    }
+
+    intersections
+}
+
+/// Returns which bbox edge a point lies on: 0=bottom, 1=right, 2=top, 3=left, -1=interior.
+fn get_bbox_edge(point: (f64, f64), min_x: f64, min_z: f64, max_x: f64, max_z: f64) -> i32 {
+    let eps = 0.5;
+
+    let on_left = (point.0 - min_x).abs() < eps;
+    let on_right = (point.0 - max_x).abs() < eps;
+    let on_bottom = (point.1 - min_z).abs() < eps;
+    let on_top = (point.1 - max_z).abs() < eps;
+
+    // Handle corners (assign to edge in counter-clockwise order)
+    if on_bottom && on_left {
+        return 3;
+    }
+    if on_bottom && on_right {
+        return 0;
+    }
+    if on_top && on_right {
+        return 1;
+    }
+    if on_top && on_left {
+        return 2;
+    }
+
+    if on_bottom {
+        return 0;
+    }
+    if on_right {
+        return 1;
+    }
+    if on_top {
+        return 2;
+    }
+    if on_left {
+        return 3;
+    }
+
+    -1
+}
+
+/// Returns corners to insert when traversing from edge1 to edge2 via shorter path.
+fn get_corners_between_edges(
+    edge1: i32,
+    edge2: i32,
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> Vec<(f64, f64)> {
+    if edge1 == edge2 || edge1 < 0 || edge2 < 0 {
+        return Vec::new();
+    }
+
+    let corners = [
+        (max_x, min_z), // 0: bottom-right
+        (max_x, max_z), // 1: top-right
+        (min_x, max_z), // 2: top-left
+        (min_x, min_z), // 3: bottom-left
+    ];
+
+    let ccw_dist = ((edge2 - edge1 + 4) % 4) as usize;
+    let cw_dist = ((edge1 - edge2 + 4) % 4) as usize;
+
+    // Opposite edges: don't insert corners
+    if ccw_dist == 2 && cw_dist == 2 {
+        return Vec::new();
+    }
+
+    let mut result = Vec::new();
+
+    if ccw_dist <= cw_dist {
+        let mut current = edge1;
+        for _ in 0..ccw_dist {
+            result.push(corners[current as usize]);
+            current = (current + 1) % 4;
+        }
+    } else {
+        let mut current = edge1;
+        for _ in 0..cw_dist {
+            current = (current + 4 - 1) % 4;
+            result.push(corners[current as usize]);
+        }
+    }
+
+    result
+}
+
+/// Inserts bbox corners where polygon transitions between different bbox edges.
+fn insert_bbox_corners(
+    polygon: Vec<(f64, f64)>,
+    min_x: f64,
+    min_z: f64,
+    max_x: f64,
+    max_z: f64,
+) -> Vec<(f64, f64)> {
+    if polygon.len() < 3 {
+        return polygon;
+    }
+
+    let mut result = Vec::with_capacity(polygon.len() + 4);
+
+    for i in 0..polygon.len() {
+        let current = polygon[i];
+        let next = polygon[(i + 1) % polygon.len()];
+
+        result.push(current);
+
+        let edge1 = get_bbox_edge(current, min_x, min_z, max_x, max_z);
+        let edge2 = get_bbox_edge(next, min_x, min_z, max_x, max_z);
+
+        if edge1 >= 0 && edge2 >= 0 && edge1 != edge2 {
+            for corner in get_corners_between_edges(edge1, edge2, min_x, min_z, max_x, max_z) {
+                result.push(corner);
+            }
+        }
+    }
+
+    result
+}
+
+/// Removes consecutive duplicate points (within epsilon tolerance).
+fn remove_consecutive_duplicates(polygon: Vec<(f64, f64)>) -> Vec<(f64, f64)> {
+    if polygon.is_empty() {
+        return polygon;
+    }
+
+    let eps = 0.1;
+    let mut result: Vec<(f64, f64)> = Vec::with_capacity(polygon.len());
+
+    for p in &polygon {
+        if let Some(last) = result.last() {
+            if (p.0 - last.0).abs() < eps && (p.1 - last.1).abs() < eps {
+                continue;
+            }
+        }
+        result.push(*p);
+    }
+
+    // Check first/last duplicates for closed polygons
+    if result.len() > 1 {
+        let first = result.first().unwrap();
+        let last = result.last().unwrap();
+        if (first.0 - last.0).abs() < eps && (first.1 - last.1).abs() < eps {
+            result.pop();
+        }
+    }
+
+    result
+}
+
+/// Checks if a clipped coordinate matches an original endpoint.
+fn matches_endpoint(coord: (f64, f64), endpoint: &ProcessedNode, tolerance: f64) -> bool {
+    let dx = (coord.0 - endpoint.x as f64).abs();
+    let dz = (coord.1 - endpoint.z as f64).abs();
+    dx * dx + dz * dz < tolerance * tolerance
+}
+
+/// Assigns node IDs to clipped coordinates, preserving original endpoint IDs.
+fn assign_node_ids_preserving_endpoints(
+    original_nodes: &[ProcessedNode],
+    clipped_coords: Vec<(f64, f64)>,
+    way_id: u64,
+) -> Vec<ProcessedNode> {
+    if clipped_coords.is_empty() {
+        return Vec::new();
+    }
+
+    let original_first = original_nodes.first();
+    let original_last = original_nodes.last();
+    let tolerance = 50.0;
+    let last_index = clipped_coords.len() - 1;
+
+    clipped_coords
+        .into_iter()
+        .enumerate()
+        .map(|(i, coord)| {
+            let is_first = i == 0;
+            let is_last = i == last_index;
+
+            if is_first || is_last {
+                if let Some(first) = original_first {
+                    if matches_endpoint(coord, first, tolerance) {
+                        return ProcessedNode {
+                            id: first.id,
+                            x: coord.0.round() as i32,
+                            z: coord.1.round() as i32,
+                            tags: HashMap::new(),
+                        };
+                    }
+                }
+                if let Some(last) = original_last {
+                    if matches_endpoint(coord, last, tolerance) {
+                        return ProcessedNode {
+                            id: last.id,
+                            x: coord.0.round() as i32,
+                            z: coord.1.round() as i32,
+                            tags: HashMap::new(),
+                        };
+                    }
+                }
+            }
+
+            ProcessedNode {
+                id: way_id.wrapping_mul(10000000).wrapping_add(i as u64),
+                x: coord.0.round() as i32,
+                z: coord.1.round() as i32,
+                tags: HashMap::new(),
+            }
+        })
+        .collect()
+}

src/data_processing.rs

@@ -1,35 +1,93 @@
 use crate::args::Args;
 use crate::block_definitions::{BEDROCK, DIRT, GRASS_BLOCK, STONE};
 use crate::coordinate_system::cartesian::XZBBox;
+use crate::coordinate_system::geographic::LLBBox;
 use crate::element_processing::*;
+use crate::floodfill_cache::FloodFillCache;
 use crate::ground::Ground;
+use crate::map_renderer;
 use crate::osm_parser::ProcessedElement;
-use crate::progress::emit_gui_progress_update;
-use crate::world_editor::WorldEditor;
+use crate::progress::{emit_gui_progress_update, emit_map_preview_ready, emit_open_mcworld_file};
+#[cfg(feature = "gui")]
+use crate::telemetry::{send_log, LogLevel};
+use crate::world_editor::{WorldEditor, WorldFormat};
 use colored::Colorize;
 use indicatif::{ProgressBar, ProgressStyle};
+use std::path::PathBuf;
+use std::sync::Arc;
 
 pub const MIN_Y: i32 = -64;
 
+/// Generation options that can be passed separately from CLI Args
+#[derive(Clone)]
+pub struct GenerationOptions {
+    pub path: PathBuf,
+    pub format: WorldFormat,
+    pub level_name: Option<String>,
+    pub spawn_point: Option<(i32, i32)>,
+}
+
 pub fn generate_world(
     elements: Vec<ProcessedElement>,
     xzbbox: XZBBox,
+    llbbox: LLBBox,
     ground: Ground,
     args: &Args,
 ) -> Result<(), String> {
-    let region_dir: String = format!("{}/region", args.path);
-    let mut editor: WorldEditor = WorldEditor::new(&region_dir, &xzbbox);
+    // Default to Java format when called from CLI
+    let options = GenerationOptions {
+        path: args.path.clone(),
+        format: WorldFormat::JavaAnvil,
+        level_name: None,
+        spawn_point: None,
+    };
+    generate_world_with_options(elements, xzbbox, llbbox, ground, args, options).map(|_| ())
+}
+
+/// Generate world with explicit format options (used by GUI for Bedrock support)
+pub fn generate_world_with_options(
+    elements: Vec<ProcessedElement>,
+    xzbbox: XZBBox,
+    llbbox: LLBBox,
+    ground: Ground,
+    args: &Args,
+    options: GenerationOptions,
+) -> Result<PathBuf, String> {
+    let output_path = options.path.clone();
+    let world_format = options.format;
+
+    // Create editor with appropriate format
+    let mut editor: WorldEditor = WorldEditor::new_with_format_and_name(
+        options.path,
+        &xzbbox,
+        llbbox,
+        options.format,
+        options.level_name.clone(),
+        options.spawn_point,
+    );
+    let ground = Arc::new(ground);
 
     println!("{} Processing data...", "[4/7]".bold());
 
+    // Build highway connectivity map once before processing
+    let highway_connectivity = highways::build_highway_connectivity_map(&elements);
+
     // Set ground reference in the editor to enable elevation-aware block placement
-    editor.set_ground(&ground);
+    editor.set_ground(Arc::clone(&ground));
 
     println!("{} Processing terrain...", "[5/7]".bold());
     emit_gui_progress_update(25.0, "Processing terrain...");
 
+    // Pre-compute all flood fills in parallel for better CPU utilization
+    let mut flood_fill_cache = FloodFillCache::precompute(&elements, args.timeout.as_ref());
+
+    // Collect building footprints to prevent trees from spawning inside buildings
+    // Uses a memory-efficient bitmap (~1 bit per coordinate) instead of a HashSet (~24 bytes per coordinate)
+    let building_footprints = flood_fill_cache.collect_building_footprints(&elements, &xzbbox);
+
     // Process data
     let elements_count: usize = elements.len();
+    let mut elements = elements; // Take ownership for consuming
     let process_pb: ProgressBar = ProgressBar::new(elements_count as u64);
     process_pb.set_style(ProgressStyle::default_bar()
         .template("{spinner:.green} [{elapsed_precise}] [{bar:45.white/black}] {pos}/{len} elements ({eta}) {msg}")
@@ -40,7 +98,8 @@ pub fn generate_world(
     let mut current_progress_prcs: f64 = 25.0;
     let mut last_emitted_progress: f64 = current_progress_prcs;
 
-    for element in &elements {
+    // Process elements by draining in insertion order
+    for element in elements.drain(..) {
         process_pb.inc(1);
         current_progress_prcs += progress_increment_prcs;
         if (current_progress_prcs - last_emitted_progress).abs() > 0.25 {
@@ -58,36 +117,69 @@ pub fn generate_world(
             process_pb.set_message("");
         }
 
-        match element {
+        match &element {
             ProcessedElement::Way(way) => {
                 if way.tags.contains_key("building") || way.tags.contains_key("building:part") {
-                    buildings::generate_buildings(&mut editor, way, args, None);
+                    buildings::generate_buildings(&mut editor, way, args, None, &flood_fill_cache);
                 } else if way.tags.contains_key("highway") {
-                    highways::generate_highways(&mut editor, element, args);
+                    highways::generate_highways(
+                        &mut editor,
+                        &element,
+                        args,
+                        &highway_connectivity,
+                        &flood_fill_cache,
+                    );
                 } else if way.tags.contains_key("landuse") {
-                    landuse::generate_landuse(&mut editor, way, args);
+                    landuse::generate_landuse(
+                        &mut editor,
+                        way,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
                 } else if way.tags.contains_key("natural") {
-                    natural::generate_natural(&mut editor, element, args);
+                    natural::generate_natural(
+                        &mut editor,
+                        &element,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
                 } else if way.tags.contains_key("amenity") {
-                    amenities::generate_amenities(&mut editor, element, args);
+                    amenities::generate_amenities(&mut editor, &element, args, &flood_fill_cache);
                 } else if way.tags.contains_key("leisure") {
-                    leisure::generate_leisure(&mut editor, way, args);
+                    leisure::generate_leisure(
+                        &mut editor,
+                        way,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
                 } else if way.tags.contains_key("barrier") {
-                    barriers::generate_barriers(&mut editor, element);
-                } else if way.tags.contains_key("waterway") {
-                    waterways::generate_waterways(&mut editor, way);
+                    barriers::generate_barriers(&mut editor, &element);
+                } else if let Some(val) = way.tags.get("waterway") {
+                    if val == "dock" {
+                        // docks count as water areas
+                        water_areas::generate_water_area_from_way(&mut editor, way, &xzbbox);
+                    } else {
+                        waterways::generate_waterways(&mut editor, way);
+                    }
                 } else if way.tags.contains_key("bridge") {
                     //bridges::generate_bridges(&mut editor, way, ground_level); // TODO FIX
                 } else if way.tags.contains_key("railway") {
                     railways::generate_railways(&mut editor, way);
+                } else if way.tags.contains_key("roller_coaster") {
+                    railways::generate_roller_coaster(&mut editor, way);
                 } else if way.tags.contains_key("aeroway") || way.tags.contains_key("area:aeroway")
                 {
                     highways::generate_aeroway(&mut editor, way, args);
                 } else if way.tags.get("service") == Some(&"siding".to_string()) {
                     highways::generate_siding(&mut editor, way);
                 } else if way.tags.contains_key("man_made") {
-                    man_made::generate_man_made(&mut editor, element, args);
+                    man_made::generate_man_made(&mut editor, &element, args);
                 }
+                // Release flood fill cache entry for this way
+                flood_fill_cache.remove_way(way.id);
             }
             ProcessedElement::Node(node) => {
                 if node.tags.contains_key("door") || node.tags.contains_key("entrance") {
@@ -95,13 +187,25 @@ pub fn generate_world(
                 } else if node.tags.contains_key("natural")
                     && node.tags.get("natural") == Some(&"tree".to_string())
                 {
-                    natural::generate_natural(&mut editor, element, args);
+                    natural::generate_natural(
+                        &mut editor,
+                        &element,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
                 } else if node.tags.contains_key("amenity") {
-                    amenities::generate_amenities(&mut editor, element, args);
+                    amenities::generate_amenities(&mut editor, &element, args, &flood_fill_cache);
                 } else if node.tags.contains_key("barrier") {
                     barriers::generate_barrier_nodes(&mut editor, node);
                 } else if node.tags.contains_key("highway") {
-                    highways::generate_highways(&mut editor, element, args);
+                    highways::generate_highways(
+                        &mut editor,
+                        &element,
+                        args,
+                        &highway_connectivity,
+                        &flood_fill_cache,
+                    );
                 } else if node.tags.contains_key("tourism") {
                     tourisms::generate_tourisms(&mut editor, node);
                 } else if node.tags.contains_key("man_made") {
@@ -110,30 +214,61 @@ pub fn generate_world(
             }
             ProcessedElement::Relation(rel) => {
                 if rel.tags.contains_key("building") || rel.tags.contains_key("building:part") {
-                    buildings::generate_building_from_relation(&mut editor, rel, args);
-                } else if rel.tags.contains_key("water")
-                    || rel.tags.get("natural") == Some(&"water".to_string())
-                {
-                    water_areas::generate_water_areas(&mut editor, rel);
-                } else if rel.tags.contains_key("natural") {
-                    natural::generate_natural_from_relation(&mut editor, rel, args);
-                } else if rel.tags.contains_key("landuse") {
-                    landuse::generate_landuse_from_relation(&mut editor, rel, args);
-                } else if rel.tags.get("leisure") == Some(&"park".to_string()) {
-                    leisure::generate_leisure_from_relation(&mut editor, rel, args);
-                } else if rel.tags.contains_key("man_made") {
-                    man_made::generate_man_made(
+                    buildings::generate_building_from_relation(
                         &mut editor,
-                        &ProcessedElement::Relation(rel.clone()),
+                        rel,
                         args,
+                        &flood_fill_cache,
                     );
+                } else if rel.tags.contains_key("water")
+                    || rel
+                        .tags
+                        .get("natural")
+                        .map(|val| val == "water" || val == "bay")
+                        .unwrap_or(false)
+                {
+                    water_areas::generate_water_areas_from_relation(&mut editor, rel, &xzbbox);
+                } else if rel.tags.contains_key("natural") {
+                    natural::generate_natural_from_relation(
+                        &mut editor,
+                        rel,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
+                } else if rel.tags.contains_key("landuse") {
+                    landuse::generate_landuse_from_relation(
+                        &mut editor,
+                        rel,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
+                } else if rel.tags.get("leisure") == Some(&"park".to_string()) {
+                    leisure::generate_leisure_from_relation(
+                        &mut editor,
+                        rel,
+                        args,
+                        &flood_fill_cache,
+                        &building_footprints,
+                    );
+                } else if rel.tags.contains_key("man_made") {
+                    man_made::generate_man_made(&mut editor, &element, args);
                 }
+                // Release flood fill cache entries for all ways in this relation
+                let way_ids: Vec<u64> = rel.members.iter().map(|m| m.way.id).collect();
+                flood_fill_cache.remove_relation_ways(&way_ids);
             }
         }
+        // Element is dropped here, freeing its memory immediately
     }
 
     process_pb.finish();
 
+    // Drop remaining caches
+    drop(highway_connectivity);
+    drop(flood_fill_cache);
+
     // Generate ground layer
     let total_blocks: u64 = xzbbox.bounding_rect().total_blocks();
     let desired_updates: u64 = 1500;
@@ -157,44 +292,72 @@ pub fn generate_world(
     let total_iterations_grnd: f64 = total_blocks as f64;
     let progress_increment_grnd: f64 = 20.0 / total_iterations_grnd;
 
-    let groundlayer_block = GRASS_BLOCK;
+    // Check if terrain elevation is enabled; when disabled, we can skip ground level lookups entirely
+    let terrain_enabled = ground.elevation_enabled;
 
-    for x in xzbbox.min_x()..=xzbbox.max_x() {
-        for z in xzbbox.min_z()..=xzbbox.max_z() {
-            // Add default dirt and grass layer if there isn't a stone layer already
-            if !editor.check_for_block(x, 0, z, Some(&[STONE])) {
-                editor.set_block(groundlayer_block, x, 0, z, None, None);
-                editor.set_block(DIRT, x, -1, z, None, None);
-                editor.set_block(DIRT, x, -2, z, None, None);
-            }
+    // Process ground generation chunk-by-chunk for better cache locality.
+    // This keeps the same region/chunk HashMap entries hot in CPU cache,
+    // rather than jumping between regions on every Z iteration.
+    let min_chunk_x = xzbbox.min_x() >> 4;
+    let max_chunk_x = xzbbox.max_x() >> 4;
+    let min_chunk_z = xzbbox.min_z() >> 4;
+    let max_chunk_z = xzbbox.max_z() >> 4;
 
-            // Fill underground with stone
-            if args.fillground {
-                // Fill from bedrock+1 to 3 blocks below ground with stone
-                editor.fill_blocks_absolute(
-                    STONE,
-                    x,
-                    MIN_Y + 1,
-                    z,
-                    x,
-                    editor.get_absolute_y(x, -3, z),
-                    z,
-                    None,
-                    None,
-                );
-            }
-            // Generate a bedrock level at MIN_Y
-            editor.set_block_absolute(BEDROCK, x, MIN_Y, z, None, Some(&[BEDROCK]));
+    for chunk_x in min_chunk_x..=max_chunk_x {
+        for chunk_z in min_chunk_z..=max_chunk_z {
+            // Calculate the block range for this chunk, clamped to bbox
+            let chunk_min_x = (chunk_x << 4).max(xzbbox.min_x());
+            let chunk_max_x = ((chunk_x << 4) + 15).min(xzbbox.max_x());
+            let chunk_min_z = (chunk_z << 4).max(xzbbox.min_z());
+            let chunk_max_z = ((chunk_z << 4) + 15).min(xzbbox.max_z());
 
-            block_counter += 1;
-            if block_counter % batch_size == 0 {
-                ground_pb.inc(batch_size);
-            }
+            for x in chunk_min_x..=chunk_max_x {
+                for z in chunk_min_z..=chunk_max_z {
+                    // Get ground level, when terrain is enabled, look it up once per block
+                    // When disabled, use constant ground_level (no function call overhead)
+                    let ground_y = if terrain_enabled {
+                        editor.get_ground_level(x, z)
+                    } else {
+                        args.ground_level
+                    };
 
-            gui_progress_grnd += progress_increment_grnd;
-            if (gui_progress_grnd - last_emitted_progress).abs() > 0.25 {
-                emit_gui_progress_update(gui_progress_grnd, "");
-                last_emitted_progress = gui_progress_grnd;
+                    // Add default dirt and grass layer if there isn't a stone layer already
+                    if !editor.check_for_block_absolute(x, ground_y, z, Some(&[STONE]), None) {
+                        editor.set_block_absolute(GRASS_BLOCK, x, ground_y, z, None, None);
+                        editor.set_block_absolute(DIRT, x, ground_y - 1, z, None, None);
+                        editor.set_block_absolute(DIRT, x, ground_y - 2, z, None, None);
+                    }
+
+                    // Fill underground with stone
+                    if args.fillground {
+                        // Fill from bedrock+1 to 3 blocks below ground with stone
+                        editor.fill_blocks_absolute(
+                            STONE,
+                            x,
+                            MIN_Y + 1,
+                            z,
+                            x,
+                            ground_y - 3,
+                            z,
+                            None,
+                            None,
+                        );
+                    }
+                    // Generate a bedrock level at MIN_Y
+                    editor.set_block_absolute(BEDROCK, x, MIN_Y, z, None, Some(&[BEDROCK]));
+
+                    block_counter += 1;
+                    #[allow(clippy::manual_is_multiple_of)]
+                    if block_counter % batch_size == 0 {
+                        ground_pb.inc(batch_size);
+                    }
+
+                    gui_progress_grnd += progress_increment_grnd;
+                    if (gui_progress_grnd - last_emitted_progress).abs() > 0.25 {
+                        emit_gui_progress_update(gui_progress_grnd, "");
+                        last_emitted_progress = gui_progress_grnd;
+                    }
+                }
             }
         }
     }
@@ -217,30 +380,109 @@ pub fn generate_world(
     // Save world
     editor.save();
 
+    emit_gui_progress_update(99.0, "Finalizing world...");
+
     // Update player spawn Y coordinate based on terrain height after generation
     #[cfg(feature = "gui")]
-    if let Some(spawn_coords) = &args.spawn_point {
+    if world_format == WorldFormat::JavaAnvil {
         use crate::gui::update_player_spawn_y_after_generation;
+        // Reconstruct bbox string to match the format that GUI originally provided.
+        // This ensures LLBBox::from_str() can parse it correctly.
         let bbox_string = format!(
             "{},{},{},{}",
-            args.bbox.min().lng(),
             args.bbox.min().lat(),
-            args.bbox.max().lng(),
-            args.bbox.max().lat()
+            args.bbox.min().lng(),
+            args.bbox.max().lat(),
+            args.bbox.max().lng()
         );
 
+        // Always update spawn Y since we now always set a spawn point (user-selected or default)
         if let Err(e) = update_player_spawn_y_after_generation(
             &args.path,
-            Some(*spawn_coords),
             bbox_string,
             args.scale,
-            &ground,
+            ground.as_ref(),
         ) {
-            eprintln!("Warning: Failed to update spawn point Y coordinate: {e}");
+            let warning_msg = format!("Failed to update spawn point Y coordinate: {}", e);
+            eprintln!("Warning: {}", warning_msg);
+            #[cfg(feature = "gui")]
+            send_log(LogLevel::Warning, &warning_msg);
         }
     }
 
-    emit_gui_progress_update(100.0, "Done! World generation completed.");
-    println!("{}", "Done! World generation completed.".green().bold());
-    Ok(())
+    // For Bedrock format, emit event to open the mcworld file
+    if world_format == WorldFormat::BedrockMcWorld {
+        if let Some(path_str) = output_path.to_str() {
+            emit_open_mcworld_file(path_str);
+        }
+    }
+
+    Ok(output_path)
+}
+
+/// Information needed to generate a map preview after world generation is complete
+#[derive(Clone)]
+pub struct MapPreviewInfo {
+    pub world_path: PathBuf,
+    pub min_x: i32,
+    pub max_x: i32,
+    pub min_z: i32,
+    pub max_z: i32,
+    pub world_area: i64,
+}
+
+impl MapPreviewInfo {
+    /// Create MapPreviewInfo from world bounds
+    pub fn new(world_path: PathBuf, xzbbox: &XZBBox) -> Self {
+        let world_width = (xzbbox.max_x() - xzbbox.min_x()) as i64;
+        let world_height = (xzbbox.max_z() - xzbbox.min_z()) as i64;
+        Self {
+            world_path,
+            min_x: xzbbox.min_x(),
+            max_x: xzbbox.max_x(),
+            min_z: xzbbox.min_z(),
+            max_z: xzbbox.max_z(),
+            world_area: world_width * world_height,
+        }
+    }
+}
+
+/// Maximum area for which map preview generation is allowed (to avoid memory issues)
+pub const MAX_MAP_PREVIEW_AREA: i64 = 6400 * 6900;
+
+/// Start map preview generation in a background thread.
+/// This should be called AFTER the world generation is complete, the session lock is released,
+/// and the GUI has been notified of 100% completion.
+///
+/// For Java worlds only, and only if the world area is within limits.
+pub fn start_map_preview_generation(info: MapPreviewInfo) {
+    if info.world_area > MAX_MAP_PREVIEW_AREA {
+        return;
+    }
+
+    std::thread::spawn(move || {
+        // Use catch_unwind to prevent any panic from affecting the application
+        let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
+            map_renderer::render_world_map(
+                &info.world_path,
+                info.min_x,
+                info.max_x,
+                info.min_z,
+                info.max_z,
+            )
+        }));
+
+        match result {
+            Ok(Ok(_path)) => {
+                // Notify the GUI that the map preview is ready
+                emit_map_preview_ready();
+            }
+            Ok(Err(e)) => {
+                eprintln!("Warning: Failed to generate map preview: {}", e);
+            }
+            Err(_) => {
+                eprintln!("Warning: Map preview generation panicked unexpectedly");
+            }
+        }
+    });
 }

src/deterministic_rng.rs

@@ -0,0 +1,127 @@
+//! Deterministic random number generation for consistent element processing.
+//!
+//! This module provides seeded RNG that ensures the same element always produces
+//! the same random values, regardless of processing order. This is essential for
+//! region-by-region streaming where the same element may be processed multiple times
+//! (once for each region it touches).
+//!
+//! # Example
+//! ```ignore
+//! let mut rng = element_rng(element_id);
+//! let color = rng.gen_bool(0.5); // Always same result for same element_id
+//! ```
+
+use rand::SeedableRng;
+use rand_chacha::ChaCha8Rng;
+
+/// Creates a deterministic RNG seeded from an element ID.
+///
+/// The same element ID will always produce the same sequence of random values,
+/// ensuring consistent results when an element is processed multiple times
+/// (e.g., once per region it touches during streaming).
+///
+/// # Arguments
+/// * `element_id` - The unique OSM element ID (way ID, node ID, or relation ID)
+///
+/// # Returns
+/// A seeded ChaCha8Rng that will produce deterministic random values
+#[inline]
+pub fn element_rng(element_id: u64) -> ChaCha8Rng {
+    ChaCha8Rng::seed_from_u64(element_id)
+}
+
+/// Creates a deterministic RNG seeded from an element ID with an additional salt.
+///
+/// Use this when you need multiple independent random sequences for the same element.
+/// For example, one sequence for wall colors and another for roof style.
+///
+/// # Arguments
+/// * `element_id` - The unique OSM element ID
+/// * `salt` - Additional value to create a different sequence (e.g., use different
+///   salt values for different purposes within the same element)
+#[inline]
+#[allow(dead_code)]
+pub fn element_rng_salted(element_id: u64, salt: u64) -> ChaCha8Rng {
+    // Combine element_id and salt using XOR and bit rotation to avoid collisions
+    let combined = element_id ^ salt.rotate_left(32);
+    ChaCha8Rng::seed_from_u64(combined)
+}
+
+/// Creates a deterministic RNG seeded from coordinates.
+///
+/// Use this for per-block randomness that needs to be consistent regardless
+/// of processing order (e.g., random flower placement within a natural area).
+///
+/// # Arguments
+/// * `x` - X coordinate
+/// * `z` - Z coordinate
+/// * `element_id` - The element ID for additional uniqueness
+#[inline]
+pub fn coord_rng(x: i32, z: i32, element_id: u64) -> ChaCha8Rng {
+    // Combine coordinates and element_id into a seed.
+    // Cast through u32 to handle negative coordinates consistently.
+    let coord_part = ((x as u32 as i64) << 32) | (z as u32 as i64);
+    let seed = (coord_part as u64) ^ element_id;
+    ChaCha8Rng::seed_from_u64(seed)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use rand::Rng;
+
+    #[test]
+    fn test_element_rng_deterministic() {
+        let mut rng1 = element_rng(12345);
+        let mut rng2 = element_rng(12345);
+
+        // Same seed should produce same sequence
+        for _ in 0..100 {
+            assert_eq!(rng1.gen::<u64>(), rng2.gen::<u64>());
+        }
+    }
+
+    #[test]
+    fn test_different_elements_different_values() {
+        let mut rng1 = element_rng(12345);
+        let mut rng2 = element_rng(12346);
+
+        // Different seeds should (almost certainly) produce different values
+        let v1: u64 = rng1.gen();
+        let v2: u64 = rng2.gen();
+        assert_ne!(v1, v2);
+    }
+
+    #[test]
+    fn test_salted_rng_different_from_base() {
+        let mut rng1 = element_rng(12345);
+        let mut rng2 = element_rng_salted(12345, 1);
+
+        let v1: u64 = rng1.gen();
+        let v2: u64 = rng2.gen();
+        assert_ne!(v1, v2);
+    }
+
+    #[test]
+    fn test_coord_rng_deterministic() {
+        let mut rng1 = coord_rng(100, 200, 12345);
+        let mut rng2 = coord_rng(100, 200, 12345);
+
+        assert_eq!(rng1.gen::<u64>(), rng2.gen::<u64>());
+    }
+
+    #[test]
+    fn test_coord_rng_negative_coordinates() {
+        // Negative coordinates are common in Minecraft worlds
+        let mut rng1 = coord_rng(-100, -200, 12345);
+        let mut rng2 = coord_rng(-100, -200, 12345);
+
+        assert_eq!(rng1.gen::<u64>(), rng2.gen::<u64>());
+
+        // Ensure different negative coords produce different seeds
+        let mut rng3 = coord_rng(-100, -200, 12345);
+        let mut rng4 = coord_rng(-101, -200, 12345);
+
+        assert_ne!(rng3.gen::<u64>(), rng4.gen::<u64>());
+    }
+}

src/element_processing/amenities.rs

@@ -2,11 +2,19 @@ use crate::args::Args;
 use crate::block_definitions::*;
 use crate::bresenham::bresenham_line;
 use crate::coordinate_system::cartesian::XZPoint;
-use crate::floodfill::flood_fill_area;
+use crate::deterministic_rng::element_rng;
+use crate::floodfill::flood_fill_area; // Needed for inline amenity flood fills
+use crate::floodfill_cache::FloodFillCache;
 use crate::osm_parser::ProcessedElement;
 use crate::world_editor::WorldEditor;
+use rand::Rng;
 
-pub fn generate_amenities(editor: &mut WorldEditor, element: &ProcessedElement, args: &Args) {
+pub fn generate_amenities(
+    editor: &mut WorldEditor,
+    element: &ProcessedElement,
+    args: &Args,
+    flood_fill_cache: &FloodFillCache,
+) {
     // Skip if 'layer' or 'level' is negative in the tags
     if let Some(layer) = element.tags().get("layer") {
         if layer.parse::<i32>().unwrap_or(0) < 0 {
@@ -42,18 +50,14 @@ pub fn generate_amenities(editor: &mut WorldEditor, element: &ProcessedElement,
                 let ground_block: Block = OAK_PLANKS;
                 let roof_block: Block = STONE_BLOCK_SLAB;
 
-                let polygon_coords: Vec<(i32, i32)> = element
-                    .nodes()
-                    .map(|n: &crate::osm_parser::ProcessedNode| (n.x, n.z))
-                    .collect();
+                // Use pre-computed flood fill from cache
+                let floor_area: Vec<(i32, i32)> =
+                    flood_fill_cache.get_or_compute_element(element, args.timeout.as_ref());
 
-                if polygon_coords.is_empty() {
+                if floor_area.is_empty() {
                     return;
                 }
 
-                let floor_area: Vec<(i32, i32)> =
-                    flood_fill_area(&polygon_coords, args.timeout.as_ref());
-
                 // Fill the floor area
                 for (x, z) in floor_area.iter() {
                     editor.set_block(ground_block, *x, 0, *z, None, None);
@@ -80,8 +84,10 @@ pub fn generate_amenities(editor: &mut WorldEditor, element: &ProcessedElement,
             "bench" => {
                 // Place a bench
                 if let Some(pt) = first_node {
-                    // 50% chance to 90 degrees rotate the bench using if
-                    if rand::random::<bool>() {
+                    // Use deterministic RNG for consistent bench orientation across region boundaries
+                    let mut rng = element_rng(element.id());
+                    // 50% chance to 90 degrees rotate the bench
+                    if rng.gen_bool(0.5) {
                         editor.set_block(SMOOTH_STONE, pt.x, 1, pt.z, None, None);
                         editor.set_block(OAK_LOG, pt.x + 1, 1, pt.z, None, None);
                         editor.set_block(OAK_LOG, pt.x - 1, 1, pt.z, None, None);
@@ -92,22 +98,12 @@ pub fn generate_amenities(editor: &mut WorldEditor, element: &ProcessedElement,
                     }
                 }
             }
-            "vending" => {
-                // Place vending machine blocks
-                if let Some(pt) = first_node {
-                    editor.set_block(IRON_BLOCK, pt.x, 1, pt.z, None, None);
-                    editor.set_block(IRON_BLOCK, pt.x, 2, pt.z, None, None);
-                }
-            }
             "shelter" => {
                 let roof_block: Block = STONE_BRICK_SLAB;
 
-                let polygon_coords: Vec<(i32, i32)> = element
-                    .nodes()
-                    .map(|n: &crate::osm_parser::ProcessedNode| (n.x, n.z))
-                    .collect();
+                // Use pre-computed flood fill from cache
                 let roof_area: Vec<(i32, i32)> =
-                    flood_fill_area(&polygon_coords, args.timeout.as_ref());
+                    flood_fill_cache.get_or_compute_element(element, args.timeout.as_ref());
 
                 // Place fences and roof slabs at each corner node directly
                 for node in element.nodes() {

src/element_processing/bridges.rs

@@ -3,37 +3,97 @@ use crate::bresenham::bresenham_line;
 use crate::osm_parser::ProcessedWay;
 use crate::world_editor::WorldEditor;
 
-// TODO FIX
+// TODO FIX - This handles ways with bridge=yes tag (e.g., highway bridges)
 #[allow(dead_code)]
 pub fn generate_bridges(editor: &mut WorldEditor, element: &ProcessedWay) {
     if let Some(_bridge_type) = element.tags.get("bridge") {
-        let bridge_height = 3; // Fixed height
+        let bridge_height = 3; // Height above the ground level
+
+        // Get start and end node elevations and use MAX for level bridge deck
+        // Using MAX ensures bridges don't dip when multiple bridge ways meet in a valley
+        let bridge_deck_ground_y = if element.nodes.len() >= 2 {
+            let start_node = &element.nodes[0];
+            let end_node = &element.nodes[element.nodes.len() - 1];
+            let start_y = editor.get_ground_level(start_node.x, start_node.z);
+            let end_y = editor.get_ground_level(end_node.x, end_node.z);
+            start_y.max(end_y)
+        } else {
+            return; // Need at least 2 nodes for a bridge
+        };
+
+        // Calculate total bridge length for ramp positioning
+        let total_length: f64 = element
+            .nodes
+            .windows(2)
+            .map(|pair| {
+                let dx = (pair[1].x - pair[0].x) as f64;
+                let dz = (pair[1].z - pair[0].z) as f64;
+                (dx * dx + dz * dz).sqrt()
+            })
+            .sum();
+
+        if total_length == 0.0 {
+            return;
+        }
+
+        let mut accumulated_length: f64 = 0.0;
 
         for i in 1..element.nodes.len() {
             let prev = &element.nodes[i - 1];
             let cur = &element.nodes[i];
+
+            let segment_dx = (cur.x - prev.x) as f64;
+            let segment_dz = (cur.z - prev.z) as f64;
+            let segment_length = (segment_dx * segment_dx + segment_dz * segment_dz).sqrt();
+
             let points = bresenham_line(prev.x, 0, prev.z, cur.x, 0, cur.z);
 
-            let total_length = points.len();
-            let ramp_length = 6; // Length of ramp at each end
+            let ramp_length = (total_length * 0.15).clamp(6.0, 20.0) as usize; // 15% of bridge, min 6, max 20 blocks
 
             for (idx, (x, _, z)) in points.iter().enumerate() {
-                let height = if idx < ramp_length {
+                // Calculate progress along this segment
+                let segment_progress = if points.len() > 1 {
+                    idx as f64 / (points.len() - 1) as f64
+                } else {
+                    0.0
+                };
+
+                // Calculate overall progress along the entire bridge
+                let point_distance = accumulated_length + segment_progress * segment_length;
+                let overall_progress = (point_distance / total_length).clamp(0.0, 1.0);
+                let total_len_usize = total_length as usize;
+                let overall_idx = (overall_progress * total_len_usize as f64) as usize;
+
+                // Calculate ramp height offset
+                let ramp_offset = if overall_idx < ramp_length {
                     // Start ramp (rising)
-                    (idx * bridge_height) / ramp_length
-                } else if idx >= total_length - ramp_length {
+                    (overall_idx as f64 * bridge_height as f64 / ramp_length as f64) as i32
+                } else if overall_idx >= total_len_usize.saturating_sub(ramp_length) {
                     // End ramp (descending)
-                    ((total_length - idx) * bridge_height) / ramp_length
+                    let dist_from_end = total_len_usize - overall_idx;
+                    (dist_from_end as f64 * bridge_height as f64 / ramp_length as f64) as i32
                 } else {
                     // Middle section (constant height)
                     bridge_height
                 };
 
+                // Use fixed bridge deck height (max of endpoints) plus ramp offset
+                let bridge_y = bridge_deck_ground_y + ramp_offset;
+
                 // Place bridge blocks
                 for dx in -2..=2 {
-                    editor.set_block(LIGHT_GRAY_CONCRETE, *x + dx, height as i32, *z, None, None);
+                    editor.set_block_absolute(
+                        LIGHT_GRAY_CONCRETE,
+                        *x + dx,
+                        bridge_y,
+                        *z,
+                        None,
+                        None,
+                    );
                 }
             }
+
+            accumulated_length += segment_length;
         }
     }
 }

src/element_processing/buildings.rs

@@ -3,8 +3,9 @@ use crate::block_definitions::*;
 use crate::bresenham::bresenham_line;
 use crate::colors::color_text_to_rgb_tuple;
 use crate::coordinate_system::cartesian::XZPoint;
+use crate::deterministic_rng::element_rng;
 use crate::element_processing::subprocessor::buildings_interior::generate_building_interior;
-use crate::floodfill::flood_fill_area;
+use crate::floodfill_cache::FloodFillCache;
 use crate::osm_parser::{ProcessedMemberRole, ProcessedRelation, ProcessedWay};
 use crate::world_editor::WorldEditor;
 use rand::Rng;
@@ -28,6 +29,7 @@ pub fn generate_buildings(
     element: &ProcessedWay,
     args: &Args,
     relation_levels: Option<i32>,
+    flood_fill_cache: &FloodFillCache,
 ) {
     // Get min_level first so we can use it both for start_level and building height calculations
     let min_level = if let Some(min_level_str) = element.tags.get("building:min_level") {
@@ -43,10 +45,9 @@ pub fn generate_buildings(
     let scale_factor = args.scale;
     let min_level_offset = multiply_scale(min_level * 4, scale_factor);
 
-    // Cache floodfill result: compute once and reuse throughout
-    let polygon_coords: Vec<(i32, i32)> = element.nodes.iter().map(|n| (n.x, n.z)).collect();
+    // Use pre-computed flood fill from cache
     let cached_floor_area: Vec<(i32, i32)> =
-        flood_fill_area(&polygon_coords, args.timeout.as_ref());
+        flood_fill_cache.get_or_compute(element, args.timeout.as_ref());
     let cached_footprint_size = cached_floor_area.len();
 
     // Use fixed starting Y coordinate based on maximum ground level when terrain is enabled
@@ -121,7 +122,8 @@ pub fn generate_buildings(
     let mut processed_points: HashSet<(i32, i32)> = HashSet::new();
     let mut building_height: i32 = ((6.0 * scale_factor) as i32).max(3); // Default building height with scale and minimum
     let mut is_tall_building = false;
-    let mut rng = rand::thread_rng();
+    // Use deterministic RNG seeded by element ID for consistent results across region boundaries
+    let mut rng = element_rng(element.id);
     let use_vertical_windows = rng.gen_bool(0.7);
     let use_accent_roof_line = rng.gen_bool(0.25);
 
@@ -386,7 +388,7 @@ pub fn generate_buildings(
                 building_height = ((23.0 * scale_factor) as i32).max(3);
             }
         } else if building_type == "bridge" {
-            generate_bridge(editor, element, args.timeout.as_ref());
+            generate_bridge(editor, element, flood_fill_cache, args.timeout.as_ref());
             return;
         }
     }
@@ -1484,6 +1486,7 @@ pub fn generate_building_from_relation(
     editor: &mut WorldEditor,
     relation: &ProcessedRelation,
     args: &Args,
+    flood_fill_cache: &FloodFillCache,
 ) {
     // Extract levels from relation tags
     let relation_levels = relation
@@ -1495,7 +1498,13 @@ pub fn generate_building_from_relation(
     // Process the outer way to create the building walls
     for member in &relation.members {
         if member.role == ProcessedMemberRole::Outer {
-            generate_buildings(editor, &member.way, args, Some(relation_levels));
+            generate_buildings(
+                editor,
+                &member.way,
+                args,
+                Some(relation_levels),
+                flood_fill_cache,
+            );
         }
     }
 
@@ -1516,52 +1525,18 @@ pub fn generate_building_from_relation(
 }
 
 /// Generates a bridge structure, paying attention to the "level" tag.
+/// Bridge deck is interpolated between start and end point elevations to avoid
+/// being dragged down by valleys underneath.
 fn generate_bridge(
     editor: &mut WorldEditor,
     element: &ProcessedWay,
+    flood_fill_cache: &FloodFillCache,
     floodfill_timeout: Option<&Duration>,
 ) {
     let floor_block: Block = STONE;
     let railing_block: Block = STONE_BRICKS;
 
-    // Process the nodes to create bridge pathways and railings
-    let mut previous_node: Option<(i32, i32)> = None;
-    for node in &element.nodes {
-        let x: i32 = node.x;
-        let z: i32 = node.z;
-
-        // Calculate bridge level based on the "level" tag
-        let bridge_y_offset = if let Some(level_str) = element.tags.get("level") {
-            if let Ok(level) = level_str.parse::<i32>() {
-                (level * 3) + 1
-            } else {
-                1 // Default elevation
-            }
-        } else {
-            1 // Default elevation
-        };
-
-        // Create bridge path using Bresenham's line
-        if let Some(prev) = previous_node {
-            let bridge_points: Vec<(i32, i32, i32)> =
-                bresenham_line(prev.0, bridge_y_offset, prev.1, x, bridge_y_offset, z);
-
-            for (bx, by, bz) in bridge_points {
-                // Place railing blocks
-                editor.set_block(railing_block, bx, by + 1, bz, None, None);
-                editor.set_block(railing_block, bx, by, bz, None, None);
-            }
-        }
-
-        previous_node = Some((x, z));
-    }
-
-    // Flood fill the area between the bridge path nodes
-    let polygon_coords: Vec<(i32, i32)> = element.nodes.iter().map(|n| (n.x, n.z)).collect();
-
-    let bridge_area: Vec<(i32, i32)> = flood_fill_area(&polygon_coords, floodfill_timeout);
-
-    // Calculate bridge level based on the "level" tag
+    // Calculate bridge level offset based on the "level" tag
     let bridge_y_offset = if let Some(level_str) = element.tags.get("level") {
         if let Ok(level) = level_str.parse::<i32>() {
             (level * 3) + 1
@@ -1572,8 +1547,51 @@ fn generate_bridge(
         1 // Default elevation
     };
 
+    // Need at least 2 nodes to form a bridge
+    if element.nodes.len() < 2 {
+        return;
+    }
+
+    // Get start and end node elevations and use MAX for level bridge deck
+    // Using MAX ensures bridges don't dip when multiple bridge ways meet in a valley
+    let start_node = &element.nodes[0];
+    let end_node = &element.nodes[element.nodes.len() - 1];
+    let start_y = editor.get_ground_level(start_node.x, start_node.z);
+    let end_y = editor.get_ground_level(end_node.x, end_node.z);
+    let bridge_deck_ground_y = start_y.max(end_y);
+
+    // Process the nodes to create bridge pathways and railings
+    let mut previous_node: Option<(i32, i32)> = None;
+
+    for node in &element.nodes {
+        let x: i32 = node.x;
+        let z: i32 = node.z;
+
+        // Create bridge path using Bresenham's line
+        if let Some(prev) = previous_node {
+            let bridge_points: Vec<(i32, i32, i32)> = bresenham_line(prev.0, 0, prev.1, x, 0, z);
+
+            for (bx, _, bz) in bridge_points.iter() {
+                // Use fixed bridge deck height (max of endpoints)
+                let bridge_y = bridge_deck_ground_y + bridge_y_offset;
+
+                // Place railing blocks
+                editor.set_block_absolute(railing_block, *bx, bridge_y + 1, *bz, None, None);
+                editor.set_block_absolute(railing_block, *bx, bridge_y, *bz, None, None);
+            }
+        }
+
+        previous_node = Some((x, z));
+    }
+
+    // Flood fill the area between the bridge path nodes (uses cache)
+    let bridge_area: Vec<(i32, i32)> = flood_fill_cache.get_or_compute(element, floodfill_timeout);
+
+    // Use the same level bridge deck height for filled areas
+    let floor_y = bridge_deck_ground_y + bridge_y_offset;
+
     // Place floor blocks
     for (x, z) in bridge_area {
-        editor.set_block(floor_block, x, bridge_y_offset, z, None, None);
+        editor.set_block_absolute(floor_block, x, floor_y, z, None, None);
     }
 }

src/element_processing/highways.rs

@@ -2,11 +2,82 @@ use crate::args::Args;
 use crate::block_definitions::*;
 use crate::bresenham::bresenham_line;
 use crate::coordinate_system::cartesian::XZPoint;
-use crate::floodfill::flood_fill_area;
+use crate::floodfill_cache::FloodFillCache;
 use crate::osm_parser::{ProcessedElement, ProcessedWay};
 use crate::world_editor::WorldEditor;
+use std::collections::HashMap;
 
-pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, args: &Args) {
+/// Type alias for highway connectivity map
+pub type HighwayConnectivityMap = HashMap<(i32, i32), Vec<i32>>;
+
+/// Minimum terrain dip (in blocks) below max endpoint elevation to classify a bridge as valley-spanning
+const VALLEY_BRIDGE_THRESHOLD: i32 = 7;
+
+/// Generates highways with elevation support based on layer tags and connectivity analysis
+pub fn generate_highways(
+    editor: &mut WorldEditor,
+    element: &ProcessedElement,
+    args: &Args,
+    highway_connectivity: &HighwayConnectivityMap,
+    flood_fill_cache: &FloodFillCache,
+) {
+    generate_highways_internal(
+        editor,
+        element,
+        args,
+        highway_connectivity,
+        flood_fill_cache,
+    );
+}
+
+/// Build a connectivity map for highway endpoints to determine where slopes are needed.
+pub fn build_highway_connectivity_map(elements: &[ProcessedElement]) -> HighwayConnectivityMap {
+    let mut connectivity_map: HashMap<(i32, i32), Vec<i32>> = HashMap::new();
+
+    for element in elements {
+        if let ProcessedElement::Way(way) = element {
+            if way.tags.contains_key("highway") {
+                let layer_value = way
+                    .tags
+                    .get("layer")
+                    .and_then(|layer| layer.parse::<i32>().ok())
+                    .unwrap_or(0);
+
+                // Treat negative layers as ground level (0) for connectivity
+                let layer_value = if layer_value < 0 { 0 } else { layer_value };
+
+                // Add connectivity for start and end nodes
+                if !way.nodes.is_empty() {
+                    let start_node = &way.nodes[0];
+                    let end_node = &way.nodes[way.nodes.len() - 1];
+
+                    let start_coord = (start_node.x, start_node.z);
+                    let end_coord = (end_node.x, end_node.z);
+
+                    connectivity_map
+                        .entry(start_coord)
+                        .or_default()
+                        .push(layer_value);
+                    connectivity_map
+                        .entry(end_coord)
+                        .or_default()
+                        .push(layer_value);
+                }
+            }
+        }
+    }
+
+    connectivity_map
+}
+
+/// Internal function that generates highways with connectivity context for elevation handling
+fn generate_highways_internal(
+    editor: &mut WorldEditor,
+    element: &ProcessedElement,
+    args: &Args,
+    highway_connectivity: &HashMap<(i32, i32), Vec<i32>>, // Maps node coordinates to list of layers that connect to this node
+    flood_fill_cache: &FloodFillCache,
+) {
     if let Some(highway_type) = element.tags().get("highway") {
         if highway_type == "street_lamp" {
             // Handle street lamps
@@ -77,14 +148,9 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                 };
             }
 
-            // Fill the area using flood fill or by iterating through the nodes
-            let polygon_coords: Vec<(i32, i32)> = way
-                .nodes
-                .iter()
-                .map(|n: &crate::osm_parser::ProcessedNode| (n.x, n.z))
-                .collect();
+            // Fill the area using flood fill cache
             let filled_area: Vec<(i32, i32)> =
-                flood_fill_area(&polygon_coords, args.timeout.as_ref());
+                flood_fill_cache.get_or_compute(way, args.timeout.as_ref());
 
             for (x, z) in filled_area {
                 editor.set_block(surface_block, x, 0, z, None, None);
@@ -97,13 +163,22 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
             let mut add_outline = false;
             let scale_factor = args.scale;
 
-            // Skip if 'layer' or 'level' is negative in the tags
-            if let Some(layer) = element.tags().get("layer") {
-                if layer.parse::<i32>().unwrap_or(0) < 0 {
-                    return;
-                }
-            }
+            // Check if this is a bridge - bridges need special elevation handling
+            // to span across valleys instead of following terrain
+            // Accept any bridge tag value except "no" (e.g., "yes", "viaduct", "aqueduct", etc.)
+            let is_bridge = element.tags().get("bridge").is_some_and(|v| v != "no");
 
+            // Parse the layer value for elevation calculation
+            let layer_value = element
+                .tags()
+                .get("layer")
+                .and_then(|layer| layer.parse::<i32>().ok())
+                .unwrap_or(0);
+
+            // Treat negative layers as ground level (0)
+            let layer_value = if layer_value < 0 { 0 } else { layer_value };
+
+            // Skip if 'level' is negative in the tags (indoor mapping)
             if let Some(level) = element.tags().get("level") {
                 if level.parse::<i32>().unwrap_or(0) < 0 {
                     return;
@@ -120,10 +195,14 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                     block_type = DIRT_PATH;
                     block_range = 1;
                 }
-                "motorway" | "primary" => {
+                "motorway" | "primary" | "trunk" => {
                     block_range = 5;
                     add_stripe = true;
                 }
+                "secondary" => {
+                    block_range = 4;
+                    add_stripe = true;
+                }
                 "tertiary" => {
                     add_stripe = true;
                 }
@@ -173,7 +252,98 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                 block_range = ((block_range as f64) * scale_factor).floor() as i32;
             }
 
+            // Calculate elevation based on layer
+            const LAYER_HEIGHT_STEP: i32 = 6; // Each layer is 6 blocks higher/lower
+            let base_elevation = layer_value * LAYER_HEIGHT_STEP;
+
+            // Check if we need slopes at start and end
+            // This is used for overpasses that need ramps to ground-level roads
+            let needs_start_slope =
+                should_add_slope_at_node(&way.nodes[0], layer_value, highway_connectivity);
+            let needs_end_slope = should_add_slope_at_node(
+                &way.nodes[way.nodes.len() - 1],
+                layer_value,
+                highway_connectivity,
+            );
+
+            // Calculate total way length for slope distribution (needed before valley bridge check)
+            let total_way_length = calculate_way_length(way);
+
+            // For bridges: detect if this spans a valley by checking terrain profile
+            // A valley bridge has terrain that dips significantly below the endpoints
+            // Skip valley detection entirely if terrain is disabled (no valleys in flat terrain)
+            // Skip very short bridges (< 25 blocks) as they're unlikely to span significant valleys
+            let terrain_enabled = editor
+                .get_ground()
+                .map(|g| g.elevation_enabled)
+                .unwrap_or(false);
+
+            let (is_valley_bridge, bridge_deck_y) =
+                if is_bridge && terrain_enabled && way.nodes.len() >= 2 && total_way_length >= 25 {
+                    let start_node = &way.nodes[0];
+                    let end_node = &way.nodes[way.nodes.len() - 1];
+                    let start_y = editor.get_ground_level(start_node.x, start_node.z);
+                    let end_y = editor.get_ground_level(end_node.x, end_node.z);
+                    let max_endpoint_y = start_y.max(end_y);
+
+                    // Sample terrain at middle nodes only (excluding endpoints we already have)
+                    // This avoids redundant get_ground_level() calls
+                    let middle_nodes = &way.nodes[1..way.nodes.len().saturating_sub(1)];
+                    let sampled_min = if middle_nodes.is_empty() {
+                        // No middle nodes, just use endpoints
+                        start_y.min(end_y)
+                    } else {
+                        // Sample up to 3 middle points (5 total with endpoints) for performance
+                        // Valleys are wide terrain features, so sparse sampling is sufficient
+                        let sample_count = middle_nodes.len().min(3);
+                        let step = if sample_count > 1 {
+                            (middle_nodes.len() - 1) / (sample_count - 1)
+                        } else {
+                            1
+                        };
+
+                        middle_nodes
+                            .iter()
+                            .step_by(step.max(1))
+                            .map(|node| editor.get_ground_level(node.x, node.z))
+                            .min()
+                            .unwrap_or(max_endpoint_y)
+                    };
+
+                    // Include endpoint elevations in the minimum calculation
+                    let min_terrain_y = sampled_min.min(start_y).min(end_y);
+
+                    // If ANY sampled point along the bridge is significantly lower than the max endpoint,
+                    // treat as valley bridge
+                    let is_valley = min_terrain_y < max_endpoint_y - VALLEY_BRIDGE_THRESHOLD;
+
+                    if is_valley {
+                        (true, max_endpoint_y)
+                    } else {
+                        (false, 0)
+                    }
+                } else {
+                    (false, 0)
+                };
+
+            // Check if this is a short isolated elevated segment (layer > 0), if so, treat as ground level
+            let is_short_isolated_elevated =
+                needs_start_slope && needs_end_slope && layer_value > 0 && total_way_length <= 35;
+
+            // Override elevation and slopes for short isolated segments
+            let (effective_elevation, effective_start_slope, effective_end_slope) =
+                if is_short_isolated_elevated {
+                    (0, false, false) // Treat as ground level
+                } else {
+                    (base_elevation, needs_start_slope, needs_end_slope)
+                };
+
+            let slope_length = (total_way_length as f32 * 0.35).clamp(15.0, 50.0) as usize; // 35% of way length, max 50 blocks, min 15 blocks
+
             // Iterate over nodes to create the highway
+            let mut segment_index = 0;
+            let total_segments = way.nodes.len() - 1;
+
             for node in &way.nodes {
                 if let Some(prev) = previous_node {
                     let (x1, z1) = prev;
@@ -181,17 +351,41 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                     let z2: i32 = node.z;
 
                     // Generate the line of coordinates between the two nodes
-                    // we don't care about the y because it's going to get overwritten
-                    // I'm not sure if we'll keep it this way
                     let bresenham_points: Vec<(i32, i32, i32)> =
                         bresenham_line(x1, 0, z1, x2, 0, z2);
 
+                    // Calculate elevation for this segment
+                    let segment_length = bresenham_points.len();
+
                     // Variables to manage dashed line pattern
                     let mut stripe_length: i32 = 0;
-                    let dash_length: i32 = (5.0 * scale_factor).ceil() as i32; // Length of the solid part of the stripe
-                    let gap_length: i32 = (5.0 * scale_factor).ceil() as i32; // Length of the gap part of the stripe
+                    let dash_length: i32 = (5.0 * scale_factor).ceil() as i32;
+                    let gap_length: i32 = (5.0 * scale_factor).ceil() as i32;
+
+                    for (point_index, (x, _, z)) in bresenham_points.iter().enumerate() {
+                        // Calculate Y elevation for this point
+                        // For valley bridges: use fixed deck height (max of endpoints) to stay level
+                        // For overpasses and regular roads: use terrain-relative elevation with slopes
+                        let (current_y, use_absolute_y) = if is_valley_bridge {
+                            // Valley bridge deck is level at the maximum endpoint elevation
+                            // Don't add base_elevation - the layer tag indicates it's above water/road,
+                            // not that it should be higher than the terrain endpoints
+                            (bridge_deck_y, true)
+                        } else {
+                            // Regular road or overpass: use terrain-relative calculation with ramps
+                            let y = calculate_point_elevation(
+                                segment_index,
+                                point_index,
+                                segment_length,
+                                total_segments,
+                                effective_elevation,
+                                effective_start_slope,
+                                effective_end_slope,
+                                slope_length,
+                            );
+                            (y, false)
+                        };
 
-                    for (x, _, z) in bresenham_points {
                         // Draw the road surface for the entire width
                         for dx in -block_range..=block_range {
                             for dz in -block_range..=block_range {
@@ -206,52 +400,150 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                                     let is_horizontal: bool = (x2 - x1).abs() >= (z2 - z1).abs();
                                     if is_horizontal {
                                         if set_x % 2 < 1 {
-                                            editor.set_block(
-                                                WHITE_CONCRETE,
+                                            if use_absolute_y {
+                                                editor.set_block_absolute(
+                                                    WHITE_CONCRETE,
+                                                    set_x,
+                                                    current_y,
+                                                    set_z,
+                                                    Some(&[BLACK_CONCRETE]),
+                                                    None,
+                                                );
+                                            } else {
+                                                editor.set_block(
+                                                    WHITE_CONCRETE,
+                                                    set_x,
+                                                    current_y,
+                                                    set_z,
+                                                    Some(&[BLACK_CONCRETE]),
+                                                    None,
+                                                );
+                                            }
+                                        } else if use_absolute_y {
+                                            editor.set_block_absolute(
+                                                BLACK_CONCRETE,
                                                 set_x,
-                                                0,
+                                                current_y,
                                                 set_z,
-                                                Some(&[BLACK_CONCRETE]),
+                                                None,
                                                 None,
                                             );
                                         } else {
                                             editor.set_block(
                                                 BLACK_CONCRETE,
                                                 set_x,
-                                                0,
+                                                current_y,
                                                 set_z,
                                                 None,
                                                 None,
                                             );
                                         }
                                     } else if set_z % 2 < 1 {
-                                        editor.set_block(
-                                            WHITE_CONCRETE,
+                                        if use_absolute_y {
+                                            editor.set_block_absolute(
+                                                WHITE_CONCRETE,
+                                                set_x,
+                                                current_y,
+                                                set_z,
+                                                Some(&[BLACK_CONCRETE]),
+                                                None,
+                                            );
+                                        } else {
+                                            editor.set_block(
+                                                WHITE_CONCRETE,
+                                                set_x,
+                                                current_y,
+                                                set_z,
+                                                Some(&[BLACK_CONCRETE]),
+                                                None,
+                                            );
+                                        }
+                                    } else if use_absolute_y {
+                                        editor.set_block_absolute(
+                                            BLACK_CONCRETE,
                                             set_x,
-                                            0,
+                                            current_y,
                                             set_z,
-                                            Some(&[BLACK_CONCRETE]),
+                                            None,
                                             None,
                                         );
                                     } else {
                                         editor.set_block(
                                             BLACK_CONCRETE,
                                             set_x,
-                                            0,
+                                            current_y,
                                             set_z,
                                             None,
                                             None,
                                         );
                                     }
-                                } else {
-                                    editor.set_block(
+                                } else if use_absolute_y {
+                                    editor.set_block_absolute(
                                         block_type,
                                         set_x,
-                                        0,
+                                        current_y,
                                         set_z,
                                         None,
                                         Some(&[BLACK_CONCRETE, WHITE_CONCRETE]),
                                     );
+                                } else {
+                                    editor.set_block(
+                                        block_type,
+                                        set_x,
+                                        current_y,
+                                        set_z,
+                                        None,
+                                        Some(&[BLACK_CONCRETE, WHITE_CONCRETE]),
+                                    );
+                                }
+
+                                // Add stone brick foundation underneath elevated highways/bridges for thickness
+                                if (effective_elevation > 0 || use_absolute_y) && current_y > 0 {
+                                    // Add 1 layer of stone bricks underneath the highway surface
+                                    if use_absolute_y {
+                                        editor.set_block_absolute(
+                                            STONE_BRICKS,
+                                            set_x,
+                                            current_y - 1,
+                                            set_z,
+                                            None,
+                                            None,
+                                        );
+                                    } else {
+                                        editor.set_block(
+                                            STONE_BRICKS,
+                                            set_x,
+                                            current_y - 1,
+                                            set_z,
+                                            None,
+                                            None,
+                                        );
+                                    }
+                                }
+
+                                // Add support pillars for elevated highways/bridges
+                                if (effective_elevation != 0 || use_absolute_y) && current_y > 0 {
+                                    if use_absolute_y {
+                                        add_highway_support_pillar_absolute(
+                                            editor,
+                                            set_x,
+                                            current_y,
+                                            set_z,
+                                            dx,
+                                            dz,
+                                            block_range,
+                                        );
+                                    } else {
+                                        add_highway_support_pillar(
+                                            editor,
+                                            set_x,
+                                            current_y,
+                                            set_z,
+                                            dx,
+                                            dz,
+                                            block_range,
+                                        );
+                                    }
                                 }
                             }
                         }
@@ -262,43 +554,76 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                             for dz in -block_range..=block_range {
                                 let outline_x = x - block_range - 1;
                                 let outline_z = z + dz;
-                                editor.set_block(
-                                    LIGHT_GRAY_CONCRETE,
-                                    outline_x,
-                                    0,
-                                    outline_z,
-                                    None,
-                                    None,
-                                );
+                                if use_absolute_y {
+                                    editor.set_block_absolute(
+                                        LIGHT_GRAY_CONCRETE,
+                                        outline_x,
+                                        current_y,
+                                        outline_z,
+                                        None,
+                                        None,
+                                    );
+                                } else {
+                                    editor.set_block(
+                                        LIGHT_GRAY_CONCRETE,
+                                        outline_x,
+                                        current_y,
+                                        outline_z,
+                                        None,
+                                        None,
+                                    );
+                                }
                             }
                             // Right outline
                             for dz in -block_range..=block_range {
                                 let outline_x = x + block_range + 1;
                                 let outline_z = z + dz;
-                                editor.set_block(
-                                    LIGHT_GRAY_CONCRETE,
-                                    outline_x,
-                                    0,
-                                    outline_z,
-                                    None,
-                                    None,
-                                );
+                                if use_absolute_y {
+                                    editor.set_block_absolute(
+                                        LIGHT_GRAY_CONCRETE,
+                                        outline_x,
+                                        current_y,
+                                        outline_z,
+                                        None,
+                                        None,
+                                    );
+                                } else {
+                                    editor.set_block(
+                                        LIGHT_GRAY_CONCRETE,
+                                        outline_x,
+                                        current_y,
+                                        outline_z,
+                                        None,
+                                        None,
+                                    );
+                                }
                             }
                         }
 
                         // Add a dashed white line in the middle for larger roads
                         if add_stripe {
                             if stripe_length < dash_length {
-                                let stripe_x: i32 = x;
-                                let stripe_z: i32 = z;
-                                editor.set_block(
-                                    WHITE_CONCRETE,
-                                    stripe_x,
-                                    0,
-                                    stripe_z,
-                                    Some(&[BLACK_CONCRETE]),
-                                    None,
-                                );
+                                let stripe_x: i32 = *x;
+                                let stripe_z: i32 = *z;
+                                if use_absolute_y {
+                                    editor.set_block_absolute(
+                                        WHITE_CONCRETE,
+                                        stripe_x,
+                                        current_y,
+                                        stripe_z,
+                                        Some(&[BLACK_CONCRETE]),
+                                        None,
+                                    );
+                                } else {
+                                    editor.set_block(
+                                        WHITE_CONCRETE,
+                                        stripe_x,
+                                        current_y,
+                                        stripe_z,
+                                        Some(&[BLACK_CONCRETE]),
+                                        None,
+                                    );
+                                }
                             }
 
                             // Increment stripe_length and reset after completing a dash and gap
@@ -308,6 +633,8 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
                             }
                         }
                     }
+
+                    segment_index += 1;
                 }
                 previous_node = Some((node.x, node.z));
             }
@@ -315,6 +642,171 @@ pub fn generate_highways(editor: &mut WorldEditor, element: &ProcessedElement, a
     }
 }
 
+/// Helper function to determine if a slope should be added at a specific node
+fn should_add_slope_at_node(
+    node: &crate::osm_parser::ProcessedNode,
+    current_layer: i32,
+    highway_connectivity: &HashMap<(i32, i32), Vec<i32>>,
+) -> bool {
+    let node_coord = (node.x, node.z);
+
+    // If we don't have connectivity information, always add slopes for non-zero layers
+    if highway_connectivity.is_empty() {
+        return current_layer != 0;
+    }
+
+    // Check if there are other highways at different layers connected to this node
+    if let Some(connected_layers) = highway_connectivity.get(&node_coord) {
+        // Count how many ways are at the same layer as current way
+        let same_layer_count = connected_layers
+            .iter()
+            .filter(|&&layer| layer == current_layer)
+            .count();
+
+        // If this is the only way at this layer connecting to this node, we need a slope
+        // (unless we're at ground level and connecting to ground level ways)
+        if same_layer_count <= 1 {
+            return current_layer != 0;
+        }
+
+        // If there are multiple ways at the same layer, don't add slope
+        false
+    } else {
+        // No other highways connected, add slope if not at ground level
+        current_layer != 0
+    }
+}
+
+/// Helper function to calculate the total length of a way in blocks
+fn calculate_way_length(way: &ProcessedWay) -> usize {
+    let mut total_length = 0;
+    let mut previous_node: Option<&crate::osm_parser::ProcessedNode> = None;
+
+    for node in &way.nodes {
+        if let Some(prev) = previous_node {
+            let dx = (node.x - prev.x).abs();
+            let dz = (node.z - prev.z).abs();
+            total_length += ((dx * dx + dz * dz) as f32).sqrt() as usize;
+        }
+        previous_node = Some(node);
+    }
+
+    total_length
+}
+
+/// Calculate the Y elevation for a specific point along the highway
+#[allow(clippy::too_many_arguments)]
+fn calculate_point_elevation(
+    segment_index: usize,
+    point_index: usize,
+    segment_length: usize,
+    total_segments: usize,
+    base_elevation: i32,
+    needs_start_slope: bool,
+    needs_end_slope: bool,
+    slope_length: usize,
+) -> i32 {
+    // If no slopes needed, return base elevation
+    if !needs_start_slope && !needs_end_slope {
+        return base_elevation;
+    }
+
+    // Calculate total distance from start
+    let total_distance_from_start = segment_index * segment_length + point_index;
+    let total_way_length = total_segments * segment_length;
+
+    // Ensure we have reasonable values
+    if total_way_length == 0 || slope_length == 0 {
+        return base_elevation;
+    }
+
+    // Start slope calculation - gradual rise from ground level
+    if needs_start_slope && total_distance_from_start <= slope_length {
+        let slope_progress = total_distance_from_start as f32 / slope_length as f32;
+        let elevation_offset = (base_elevation as f32 * slope_progress) as i32;
+        return elevation_offset;
+    }
+
+    // End slope calculation - gradual descent to ground level
+    if needs_end_slope
+        && total_distance_from_start >= (total_way_length.saturating_sub(slope_length))
+    {
+        let distance_from_end = total_way_length - total_distance_from_start;
+        let slope_progress = distance_from_end as f32 / slope_length as f32;
+        let elevation_offset = (base_elevation as f32 * slope_progress) as i32;
+        return elevation_offset;
+    }
+
+    // Middle section at full elevation
+    base_elevation
+}
+
+/// Add support pillars for elevated highways
+fn add_highway_support_pillar(
+    editor: &mut WorldEditor,
+    x: i32,
+    highway_y: i32,
+    z: i32,
+    dx: i32,
+    dz: i32,
+    _block_range: i32, // Keep for future use
+) {
+    // Only add pillars at specific intervals and positions
+    if dx == 0 && dz == 0 && (x + z) % 8 == 0 {
+        // Add pillar from ground to highway level
+        for y in 1..highway_y {
+            editor.set_block(STONE_BRICKS, x, y, z, None, None);
+        }
+
+        // Add pillar base
+        for base_dx in -1..=1 {
+            for base_dz in -1..=1 {
+                editor.set_block(STONE_BRICKS, x + base_dx, 0, z + base_dz, None, None);
+            }
+        }
+    }
+}
+
+/// Add support pillars for bridges using absolute Y coordinates
+/// Pillars extend from ground level up to the bridge deck
+fn add_highway_support_pillar_absolute(
+    editor: &mut WorldEditor,
+    x: i32,
+    bridge_deck_y: i32,
+    z: i32,
+    dx: i32,
+    dz: i32,
+    _block_range: i32, // Keep for future use
+) {
+    // Only add pillars at specific intervals and positions
+    if dx == 0 && dz == 0 && (x + z) % 8 == 0 {
+        // Get the actual ground level at this position
+        let ground_y = editor.get_ground_level(x, z);
+
+        // Add pillar from ground up to bridge deck
+        // Only if the bridge is actually above the ground
+        if bridge_deck_y > ground_y {
+            for y in (ground_y + 1)..bridge_deck_y {
+                editor.set_block_absolute(STONE_BRICKS, x, y, z, None, None);
+            }
+
+            // Add pillar base at ground level
+            for base_dx in -1..=1 {
+                for base_dz in -1..=1 {
+                    editor.set_block_absolute(
+                        STONE_BRICKS,
+                        x + base_dx,
+                        ground_y,
+                        z + base_dz,
+                        None,
+                        None,
+                    );
+                }
+            }
+        }
+    }
+}
+
 /// Generates a siding using stone brick slabs
 pub fn generate_siding(editor: &mut WorldEditor, element: &ProcessedWay) {
     let mut previous_node: Option<XZPoint> = None;

src/element_processing/landuse.rs

@@ -1,16 +1,26 @@
 use crate::args::Args;
 use crate::block_definitions::*;
+use crate::deterministic_rng::element_rng;
 use crate::element_processing::tree::Tree;
-use crate::floodfill::flood_fill_area;
+use crate::floodfill_cache::{BuildingFootprintBitmap, FloodFillCache};
 use crate::osm_parser::{ProcessedMemberRole, ProcessedRelation, ProcessedWay};
 use crate::world_editor::WorldEditor;
 use rand::Rng;
 
-pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args: &Args) {
+pub fn generate_landuse(
+    editor: &mut WorldEditor,
+    element: &ProcessedWay,
+    args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
+) {
     // Determine block type based on landuse tag
     let binding: String = "".to_string();
     let landuse_tag: &String = element.tags.get("landuse").unwrap_or(&binding);
 
+    // Use deterministic RNG seeded by element ID for consistent results across region boundaries
+    let mut rng = element_rng(element.id);
+
     let block_type = match landuse_tag.as_str() {
         "greenfield" | "meadow" | "grass" | "orchard" | "forest" => GRASS_BLOCK,
         "farmland" => FARMLAND,
@@ -22,13 +32,13 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
             if residential_tag == "rural" {
                 GRASS_BLOCK
             } else {
-                STONE_BRICKS
+                STONE_BRICKS // Placeholder, will be randomized per-block
             }
         }
-        "commercial" => SMOOTH_STONE,
+        "commercial" => SMOOTH_STONE, // Placeholder, will be randomized per-block
         "education" => POLISHED_ANDESITE,
         "religious" => POLISHED_ANDESITE,
-        "industrial" => COBBLESTONE,
+        "industrial" => STONE, // Placeholder, will be randomized per-block
         "military" => GRAY_CONCRETE,
         "railway" => GRAVEL,
         "landfill" => {
@@ -44,19 +54,56 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
         _ => GRASS_BLOCK,
     };
 
-    // Get the area of the landuse element
-    let polygon_coords: Vec<(i32, i32)> = element.nodes.iter().map(|n| (n.x, n.z)).collect();
-    let floor_area: Vec<(i32, i32)> = flood_fill_area(&polygon_coords, args.timeout.as_ref());
-
-    let mut rng: rand::prelude::ThreadRng = rand::thread_rng();
+    // Get the area of the landuse element using cache
+    let floor_area: Vec<(i32, i32)> =
+        flood_fill_cache.get_or_compute(element, args.timeout.as_ref());
 
     for (x, z) in floor_area {
-        if landuse_tag == "traffic_island" {
-            editor.set_block(block_type, x, 1, z, None, None);
-        } else if landuse_tag == "construction" || landuse_tag == "railway" {
-            editor.set_block(block_type, x, 0, z, None, Some(&[SPONGE]));
+        // Apply per-block randomness for certain landuse types
+        let actual_block = if landuse_tag == "residential" && block_type == STONE_BRICKS {
+            // Urban residential: mix of stone bricks, cracked stone bricks, stone, cobblestone
+            let random_value = rng.gen_range(0..100);
+            if random_value < 72 {
+                STONE_BRICKS
+            } else if random_value < 87 {
+                CRACKED_STONE_BRICKS
+            } else if random_value < 92 {
+                STONE
+            } else {
+                COBBLESTONE
+            }
+        } else if landuse_tag == "commercial" {
+            // Commercial: mix of smooth stone, stone, cobblestone, stone bricks
+            let random_value = rng.gen_range(0..100);
+            if random_value < 40 {
+                SMOOTH_STONE
+            } else if random_value < 70 {
+                STONE_BRICKS
+            } else if random_value < 90 {
+                STONE
+            } else {
+                COBBLESTONE
+            }
+        } else if landuse_tag == "industrial" {
+            // Industrial: primarily stone, with some stone bricks and smooth stone
+            let random_value = rng.gen_range(0..100);
+            if random_value < 70 {
+                STONE
+            } else if random_value < 90 {
+                STONE_BRICKS
+            } else {
+                SMOOTH_STONE
+            }
         } else {
-            editor.set_block(block_type, x, 0, z, None, None);
+            block_type
+        };
+
+        if landuse_tag == "traffic_island" {
+            editor.set_block(actual_block, x, 1, z, None, None);
+        } else if landuse_tag == "construction" || landuse_tag == "railway" {
+            editor.set_block(actual_block, x, 0, z, None, Some(&[SPONGE]));
+        } else {
+            editor.set_block(actual_block, x, 0, z, None, None);
         }
 
         // Add specific features for different landuse types
@@ -84,7 +131,7 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                             editor.set_block(RED_FLOWER, x, 1, z, None, None);
                         }
                     } else if random_choice < 33 {
-                        Tree::create(editor, (x, 1, z));
+                        Tree::create(editor, (x, 1, z), Some(building_footprints));
                     } else if random_choice < 35 {
                         editor.set_block(OAK_LEAVES, x, 1, z, None, None);
                     }
@@ -94,7 +141,7 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                 if editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK])) {
                     let random_choice: i32 = rng.gen_range(0..30);
                     if random_choice == 20 {
-                        Tree::create(editor, (x, 1, z));
+                        Tree::create(editor, (x, 1, z), Some(building_footprints));
                     } else if random_choice == 2 {
                         let flower_block: Block = match rng.gen_range(1..=5) {
                             1 => OAK_LEAVES,
@@ -105,7 +152,11 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                         };
                         editor.set_block(flower_block, x, 1, z, None, None);
                     } else if random_choice <= 12 {
-                        editor.set_block(GRASS, x, 1, z, None, None);
+                        if rng.gen_range(0..100) < 12 {
+                            editor.set_block(FERN, x, 1, z, None, None);
+                        } else {
+                            editor.set_block(GRASS, x, 1, z, None, None);
+                        }
                     }
                 }
             }
@@ -207,7 +258,8 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                 if editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK])) {
                     match rng.gen_range(0..200) {
                         0 => editor.set_block(OAK_LEAVES, x, 1, z, None, None),
-                        1..=170 => editor.set_block(GRASS, x, 1, z, None, None),
+                        1..=8 => editor.set_block(FERN, x, 1, z, None, None),
+                        9..=170 => editor.set_block(GRASS, x, 1, z, None, None),
                         _ => {}
                     }
                 }
@@ -216,7 +268,8 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                 if editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK])) {
                     match rng.gen_range(0..200) {
                         0 => editor.set_block(OAK_LEAVES, x, 1, z, None, None),
-                        1..=17 => editor.set_block(GRASS, x, 1, z, None, None),
+                        1..=2 => editor.set_block(FERN, x, 1, z, None, None),
+                        3..=17 => editor.set_block(GRASS, x, 1, z, None, None),
                         _ => {}
                     }
                 }
@@ -225,11 +278,13 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
                 if editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK])) {
                     let random_choice: i32 = rng.gen_range(0..1001);
                     if random_choice < 5 {
-                        Tree::create(editor, (x, 1, z));
+                        Tree::create(editor, (x, 1, z), Some(building_footprints));
                     } else if random_choice < 6 {
                         editor.set_block(RED_FLOWER, x, 1, z, None, None);
                     } else if random_choice < 9 {
                         editor.set_block(OAK_LEAVES, x, 1, z, None, None);
+                    } else if random_choice < 40 {
+                        editor.set_block(FERN, x, 1, z, None, None);
                     } else if random_choice < 800 {
                         editor.set_block(GRASS, x, 1, z, None, None);
                     }
@@ -237,11 +292,12 @@ pub fn generate_landuse(editor: &mut WorldEditor, element: &ProcessedWay, args:
             }
             "orchard" => {
                 if x % 18 == 0 && z % 10 == 0 {
-                    Tree::create(editor, (x, 1, z));
+                    Tree::create(editor, (x, 1, z), Some(building_footprints));
                 } else if editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK])) {
                     match rng.gen_range(0..100) {
                         0 => editor.set_block(OAK_LEAVES, x, 1, z, None, None),
-                        1..=20 => editor.set_block(GRASS, x, 1, z, None, None),
+                        1..=2 => editor.set_block(FERN, x, 1, z, None, None),
+                        3..=20 => editor.set_block(GRASS, x, 1, z, None, None),
                         _ => {}
                     }
                 }
@@ -275,12 +331,20 @@ pub fn generate_landuse_from_relation(
     editor: &mut WorldEditor,
     rel: &ProcessedRelation,
     args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
 ) {
     if rel.tags.contains_key("landuse") {
         // Generate individual ways with their original tags
         for member in &rel.members {
             if member.role == ProcessedMemberRole::Outer {
-                generate_landuse(editor, &member.way.clone(), args);
+                generate_landuse(
+                    editor,
+                    &member.way.clone(),
+                    args,
+                    flood_fill_cache,
+                    building_footprints,
+                );
             }
         }
 
@@ -302,7 +366,13 @@ pub fn generate_landuse_from_relation(
             };
 
             // Generate landuse area from combined way
-            generate_landuse(editor, &combined_way, args);
+            generate_landuse(
+                editor,
+                &combined_way,
+                args,
+                flood_fill_cache,
+                building_footprints,
+            );
         }
     }
 }

src/element_processing/leisure.rs

@@ -1,13 +1,20 @@
 use crate::args::Args;
 use crate::block_definitions::*;
 use crate::bresenham::bresenham_line;
+use crate::deterministic_rng::element_rng;
 use crate::element_processing::tree::Tree;
-use crate::floodfill::flood_fill_area;
+use crate::floodfill_cache::{BuildingFootprintBitmap, FloodFillCache};
 use crate::osm_parser::{ProcessedMemberRole, ProcessedRelation, ProcessedWay};
 use crate::world_editor::WorldEditor;
 use rand::Rng;
 
-pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args: &Args) {
+pub fn generate_leisure(
+    editor: &mut WorldEditor,
+    element: &ProcessedWay,
+    args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
+) {
     if let Some(leisure_type) = element.tags.get("leisure") {
         let mut previous_node: Option<(i32, i32)> = None;
         let mut corner_addup: (i32, i32, i32) = (0, 0, 0);
@@ -18,6 +25,7 @@ pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args:
             "park" | "nature_reserve" | "garden" | "disc_golf_course" | "golf_course" => {
                 GRASS_BLOCK
             }
+            "schoolyard" => BLACK_CONCRETE,
             "playground" | "recreation_ground" | "pitch" | "beach_resort" | "dog_park" => {
                 if let Some(surface) = element.tags.get("surface") {
                     match surface.as_str() {
@@ -73,15 +81,13 @@ pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args:
             previous_node = Some((node.x, node.z));
         }
 
-        // Flood-fill the interior of the leisure area
+        // Flood-fill the interior of the leisure area using cache
         if corner_addup != (0, 0, 0) {
-            let polygon_coords: Vec<(i32, i32)> = element
-                .nodes
-                .iter()
-                .map(|n: &crate::osm_parser::ProcessedNode| (n.x, n.z))
-                .collect();
             let filled_area: Vec<(i32, i32)> =
-                flood_fill_area(&polygon_coords, args.timeout.as_ref());
+                flood_fill_cache.get_or_compute(element, args.timeout.as_ref());
+
+            // Use deterministic RNG seeded by element ID for consistent results across region boundaries
+            let mut rng = element_rng(element.id);
 
             for (x, z) in filled_area {
                 editor.set_block(block_type, x, 0, z, Some(&[GRASS_BLOCK]), None);
@@ -90,7 +96,6 @@ pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args:
                 if matches!(leisure_type.as_str(), "park" | "garden" | "nature_reserve")
                     && editor.check_for_block(x, 0, z, Some(&[GRASS_BLOCK]))
                 {
-                    let mut rng: rand::prelude::ThreadRng = rand::thread_rng();
                     let random_choice: i32 = rng.gen_range(0..1000);
 
                     match random_choice {
@@ -114,7 +119,7 @@ pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args:
                         }
                         105..120 => {
                             // Tree
-                            Tree::create(editor, (x, 1, z));
+                            Tree::create(editor, (x, 1, z), Some(building_footprints));
                         }
                         _ => {}
                     }
@@ -122,7 +127,6 @@ pub fn generate_leisure(editor: &mut WorldEditor, element: &ProcessedWay, args:
 
                 // Add playground or recreation ground features
                 if matches!(leisure_type.as_str(), "playground" | "recreation_ground") {
-                    let mut rng: rand::prelude::ThreadRng = rand::thread_rng();
                     let random_choice: i32 = rng.gen_range(0..5000);
 
                     match random_choice {
@@ -175,12 +179,20 @@ pub fn generate_leisure_from_relation(
     editor: &mut WorldEditor,
     rel: &ProcessedRelation,
     args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
 ) {
     if rel.tags.get("leisure") == Some(&"park".to_string()) {
         // First generate individual ways with their original tags
         for member in &rel.members {
             if member.role == ProcessedMemberRole::Outer {
-                generate_leisure(editor, &member.way, args);
+                generate_leisure(
+                    editor,
+                    &member.way,
+                    args,
+                    flood_fill_cache,
+                    building_footprints,
+                );
             }
         }
 
@@ -200,6 +212,12 @@ pub fn generate_leisure_from_relation(
         };
 
         // Generate leisure area from combined way
-        generate_leisure(editor, &combined_way, args);
+        generate_leisure(
+            editor,
+            &combined_way,
+            args,
+            flood_fill_cache,
+            building_footprints,
+        );
     }
 }

src/element_processing/man_made.rs

@@ -25,6 +25,7 @@ pub fn generate_man_made(editor: &mut WorldEditor, element: &ProcessedElement, _
             "chimney" => generate_chimney(editor, element),
             "water_well" => generate_water_well(editor, element),
             "water_tower" => generate_water_tower(editor, element),
+            "mast" => generate_antenna(editor, element),
             _ => {} // Unknown man_made type, ignore
         }
     }
@@ -96,7 +97,6 @@ fn generate_antenna(editor: &mut WorldEditor, element: &ProcessedElement) {
             Some(h) => h.parse::<i32>().unwrap_or(20).min(40), // Max 40 blocks
             None => match element.tags().get("tower:type").map(|s| s.as_str()) {
                 Some("communication") => 20,
-                Some("transmission") => 25,
                 Some("cellular") => 15,
                 _ => 20,
             },
@@ -249,6 +249,7 @@ pub fn generate_man_made_nodes(editor: &mut WorldEditor, node: &ProcessedNode) {
             "chimney" => generate_chimney(editor, &element),
             "water_well" => generate_water_well(editor, &element),
             "water_tower" => generate_water_tower(editor, &element),
+            "mast" => generate_antenna(editor, &element),
             _ => {} // Unknown man_made type, ignore
         }
     }

src/element_processing/natural.rs

@@ -1,20 +1,27 @@
 use crate::args::Args;
 use crate::block_definitions::*;
 use crate::bresenham::bresenham_line;
+use crate::deterministic_rng::element_rng;
 use crate::element_processing::tree::Tree;
-use crate::floodfill::flood_fill_area;
+use crate::floodfill_cache::{BuildingFootprintBitmap, FloodFillCache};
 use crate::osm_parser::{ProcessedElement, ProcessedMemberRole, ProcessedRelation, ProcessedWay};
 use crate::world_editor::WorldEditor;
 use rand::Rng;
 
-pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, args: &Args) {
+pub fn generate_natural(
+    editor: &mut WorldEditor,
+    element: &ProcessedElement,
+    args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
+) {
     if let Some(natural_type) = element.tags().get("natural") {
         if natural_type == "tree" {
             if let ProcessedElement::Node(node) = element {
                 let x: i32 = node.x;
                 let z: i32 = node.z;
 
-                Tree::create(editor, (x, 1, z));
+                Tree::create(editor, (x, 1, z), Some(building_footprints));
             }
         } else {
             let mut previous_node: Option<(i32, i32)> = None;
@@ -69,17 +76,13 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                 previous_node = Some((x, z));
             }
 
-            // If there are natural nodes, flood-fill the area
+            // If there are natural nodes, flood-fill the area using cache
             if corner_addup != (0, 0, 0) {
-                let polygon_coords: Vec<(i32, i32)> = way
-                    .nodes
-                    .iter()
-                    .map(|n: &crate::osm_parser::ProcessedNode| (n.x, n.z))
-                    .collect();
                 let filled_area: Vec<(i32, i32)> =
-                    flood_fill_area(&polygon_coords, args.timeout.as_ref());
+                    flood_fill_cache.get_or_compute(way, args.timeout.as_ref());
 
-                let mut rng: rand::prelude::ThreadRng = rand::thread_rng();
+                // Use deterministic RNG seeded by element ID for consistent results across region boundaries
+                let mut rng = element_rng(way.id);
 
                 for (x, z) in filled_area {
                     editor.set_block(block_type, x, 0, z, None, None);
@@ -132,7 +135,7 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                             }
                             let random_choice = rng.gen_range(0..500);
                             if random_choice == 0 {
-                                Tree::create(editor, (x, 1, z));
+                                Tree::create(editor, (x, 1, z), Some(building_footprints));
                             } else if random_choice == 1 {
                                 let flower_block = match rng.gen_range(1..=4) {
                                     1 => RED_FLOWER,
@@ -161,7 +164,7 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                             }
                             let random_choice: i32 = rng.gen_range(0..30);
                             if random_choice == 0 {
-                                Tree::create(editor, (x, 1, z));
+                                Tree::create(editor, (x, 1, z), Some(building_footprints));
                             } else if random_choice == 1 {
                                 let flower_block = match rng.gen_range(1..=4) {
                                     1 => RED_FLOWER,
@@ -220,7 +223,11 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                                         // TODO implement mangrove
                                         let random_choice: i32 = rng.gen_range(0..40);
                                         if random_choice == 0 {
-                                            Tree::create(editor, (x, 1, z));
+                                            Tree::create(
+                                                editor,
+                                                (x, 1, z),
+                                                Some(building_footprints),
+                                            );
                                         } else if random_choice < 35 {
                                             editor.set_block(GRASS, x, 1, z, None, None);
                                         }
@@ -304,6 +311,7 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                                                         Tree::create(
                                                             editor,
                                                             (cluster_x, 1, cluster_z),
+                                                            Some(building_footprints),
                                                         );
                                                     } else if vegetation_chance < 15 {
                                                         // 15% chance for grass
@@ -416,7 +424,7 @@ pub fn generate_natural(editor: &mut WorldEditor, element: &ProcessedElement, ar
                             let hill_chance = rng.gen_range(0..1000);
                             if hill_chance == 0 {
                                 // 0.1% chance for rare trees
-                                Tree::create(editor, (x, 1, z));
+                                Tree::create(editor, (x, 1, z), Some(building_footprints));
                             } else if hill_chance < 50 {
                                 // 5% chance for flowers
                                 let flower_block = match rng.gen_range(1..=4) {
@@ -448,12 +456,20 @@ pub fn generate_natural_from_relation(
     editor: &mut WorldEditor,
     rel: &ProcessedRelation,
     args: &Args,
+    flood_fill_cache: &FloodFillCache,
+    building_footprints: &BuildingFootprintBitmap,
 ) {
     if rel.tags.contains_key("natural") {
         // Generate individual ways with their original tags
         for member in &rel.members {
             if member.role == ProcessedMemberRole::Outer {
-                generate_natural(editor, &ProcessedElement::Way(member.way.clone()), args);
+                generate_natural(
+                    editor,
+                    &ProcessedElement::Way((*member.way).clone()),
+                    args,
+                    flood_fill_cache,
+                    building_footprints,
+                );
             }
         }
 
@@ -475,7 +491,13 @@ pub fn generate_natural_from_relation(
             };
 
             // Generate natural area from combined way
-            generate_natural(editor, &ProcessedElement::Way(combined_way), args);
+            generate_natural(
+                editor,
+                &ProcessedElement::Way(combined_way),
+                args,
+                flood_fill_cache,
+                building_footprints,
+            );
         }
     }
 }

src/element_processing/railways.rs

@@ -174,3 +174,71 @@ fn determine_rail_direction(
         (None, None) => RAIL_NORTH_SOUTH,
     }
 }
+
+pub fn generate_roller_coaster(editor: &mut WorldEditor, element: &ProcessedWay) {
+    if let Some(roller_coaster) = element.tags.get("roller_coaster") {
+        if roller_coaster == "track" {
+            // Check if it's indoor (skip if yes)
+            if let Some(indoor) = element.tags.get("indoor") {
+                if indoor == "yes" {
+                    return;
+                }
+            }
+
+            // Check if layer is negative (skip if yes)
+            if let Some(layer) = element.tags.get("layer") {
+                if let Ok(layer_value) = layer.parse::<i32>() {
+                    if layer_value < 0 {
+                        return;
+                    }
+                }
+            }
+
+            let elevation_height = 4; // 4 blocks in the air
+            let pillar_interval = 6; // Support pillars every 6 blocks
+
+            for i in 1..element.nodes.len() {
+                let prev_node = element.nodes[i - 1].xz();
+                let cur_node = element.nodes[i].xz();
+
+                let points = bresenham_line(prev_node.x, 0, prev_node.z, cur_node.x, 0, cur_node.z);
+                let smoothed_points = smooth_diagonal_rails(&points);
+
+                for j in 0..smoothed_points.len() {
+                    let (bx, _, bz) = smoothed_points[j];
+
+                    // Place track foundation at elevation height
+                    editor.set_block(IRON_BLOCK, bx, elevation_height, bz, None, None);
+
+                    let prev = if j > 0 {
+                        Some(smoothed_points[j - 1])
+                    } else {
+                        None
+                    };
+                    let next = if j < smoothed_points.len() - 1 {
+                        Some(smoothed_points[j + 1])
+                    } else {
+                        None
+                    };
+
+                    let rail_block = determine_rail_direction(
+                        (bx, bz),
+                        prev.map(|(x, _, z)| (x, z)),
+                        next.map(|(x, _, z)| (x, z)),
+                    );
+
+                    // Place rail on top of the foundation
+                    editor.set_block(rail_block, bx, elevation_height + 1, bz, None, None);
+
+                    // Place support pillars every pillar_interval blocks
+                    if bx % pillar_interval == 0 && bz % pillar_interval == 0 {
+                        // Create a pillar from ground level up to the track
+                        for y in 1..elevation_height {
+                            editor.set_block(IRON_BLOCK, bx, y, bz, None, None);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/element_processing/subprocessor/buildings_interior.rs

@@ -133,7 +133,7 @@ pub fn get_interior_block(c: char, is_layer2: bool, wall_block: Block) -> Option
         '6' => Some(RED_BED_SOUTH_FOOT), // Bed South Foot
         '7' => Some(RED_BED_WEST_HEAD),  // Bed West Head
         '8' => Some(RED_BED_WEST_FOOT),  // Bed West Foot
-        'H' => Some(CHEST),              // Chest
+        // 'H' => Some(CHEST),           // Chest
         'L' => Some(CAULDRON),           // Cauldron
         'A' => Some(ANVIL),              // Anvil
         'P' => Some(OAK_PRESSURE_PLATE), // Pressure Plate
@@ -145,7 +145,7 @@ pub fn get_interior_block(c: char, is_layer2: bool, wall_block: Block) -> Option
                 Some(DARK_OAK_DOOR_LOWER)
             }
         }
-        'J' => Some(JUKEBOX),       // Jukebox
+        'J' => Some(NOTE_BLOCK),    // Note block
         'G' => Some(GLOWSTONE),     // Glowstone
         'N' => Some(BREWING_STAND), // Brewing Stand
         'T' => Some(WHITE_CARPET),  // White Carpet

src/element_processing/tree.rs

@@ -1,4 +1,6 @@
 use crate::block_definitions::*;
+use crate::deterministic_rng::coord_rng;
+use crate::floodfill_cache::BuildingFootprintBitmap;
 use crate::world_editor::WorldEditor;
 use rand::Rng;
 
@@ -107,7 +109,25 @@ pub struct Tree<'a> {
 }
 
 impl Tree<'_> {
-    pub fn create(editor: &mut WorldEditor, (x, y, z): Coord) {
+    /// Creates a tree at the specified coordinates.
+    ///
+    /// # Arguments
+    /// * `editor` - The world editor to place blocks
+    /// * `(x, y, z)` - The base coordinates for the tree
+    /// * `building_footprints` - Optional bitmap of (x, z) coordinates that are inside buildings.
+    ///   If provided, trees will not be placed at coordinates within this bitmap.
+    pub fn create(
+        editor: &mut WorldEditor,
+        (x, y, z): Coord,
+        building_footprints: Option<&BuildingFootprintBitmap>,
+    ) {
+        // Skip if this coordinate is inside a building
+        if let Some(footprints) = building_footprints {
+            if footprints.contains(x, z) {
+                return;
+            }
+        }
+
         let mut blacklist: Vec<Block> = Vec::new();
         blacklist.extend(Self::get_building_wall_blocks());
         blacklist.extend(Self::get_building_floor_blocks());
@@ -115,7 +135,9 @@ impl Tree<'_> {
         blacklist.extend(Self::get_functional_blocks());
         blacklist.push(WATER);
 
-        let mut rng = rand::thread_rng();
+        // Use deterministic RNG based on coordinates for consistent tree types across region boundaries
+        // The element_id of 0 is used as a salt for tree-specific randomness
+        let mut rng = coord_rng(x, z, 0);
 
         let tree = Self::get_tree(match rng.gen_range(1..=3) {
             1 => TreeType::Oak,
@@ -307,7 +329,7 @@ impl Tree<'_> {
             FURNACE,
             ANVIL,
             BREWING_STAND,
-            JUKEBOX,
+            NOTE_BLOCK,
             BOOKSHELF,
             CAULDRON,
             // Beds

src/element_processing/water_areas.rs

@@ -1,19 +1,40 @@
+use geo::orient::{Direction, Orient};
 use geo::{Contains, Intersects, LineString, Point, Polygon, Rect};
-use std::time::Instant;
 
+use crate::clipping::clip_water_ring_to_bbox;
 use crate::{
     block_definitions::WATER,
-    coordinate_system::cartesian::XZPoint,
-    osm_parser::{ProcessedMemberRole, ProcessedNode, ProcessedRelation},
+    coordinate_system::cartesian::{XZBBox, XZPoint},
+    osm_parser::{ProcessedMemberRole, ProcessedNode, ProcessedRelation, ProcessedWay},
     world_editor::WorldEditor,
 };
 
-pub fn generate_water_areas(editor: &mut WorldEditor, element: &ProcessedRelation) {
-    let start_time = Instant::now();
+pub fn generate_water_area_from_way(
+    editor: &mut WorldEditor,
+    element: &ProcessedWay,
+    _xzbbox: &XZBBox,
+) {
+    let outers = [element.nodes.clone()];
+    if !verify_closed_rings(&outers) {
+        println!("Skipping way {} due to invalid polygon", element.id);
+        return;
+    }
 
+    generate_water_areas(editor, &outers, &[]);
+}
+
+pub fn generate_water_areas_from_relation(
+    editor: &mut WorldEditor,
+    element: &ProcessedRelation,
+    xzbbox: &XZBBox,
+) {
     // Check if this is a water relation (either with water tag or natural=water)
     let is_water = element.tags.contains_key("water")
-        || element.tags.get("natural") == Some(&"water".to_string());
+        || element
+            .tags
+            .get("natural")
+            .map(|val| val == "water" || val == "bay")
+            .unwrap_or(false);
 
     if !is_water {
         return;
@@ -36,79 +57,132 @@ pub fn generate_water_areas(editor: &mut WorldEditor, element: &ProcessedRelatio
         }
     }
 
-    // Process each outer polygon individually
-    for (i, outer_nodes) in outers.iter().enumerate() {
-        let mut individual_outers = vec![outer_nodes.clone()];
+    // Preserve OSM-defined outer/inner roles without modification
+    merge_way_segments(&mut outers);
 
-        merge_loopy_loops(&mut individual_outers);
-        if !verify_loopy_loops(&individual_outers) {
-            println!(
-                "Skipping invalid outer polygon {} for relation {}",
-                i + 1,
-                element.id
-            );
-            continue; // Skip this outer if it's not valid
+    // Clip assembled rings to bbox (must happen after merging to preserve ring connectivity)
+    outers = outers
+        .into_iter()
+        .filter_map(|ring| clip_water_ring_to_bbox(&ring, xzbbox))
+        .collect();
+    merge_way_segments(&mut inners);
+    inners = inners
+        .into_iter()
+        .filter_map(|ring| clip_water_ring_to_bbox(&ring, xzbbox))
+        .collect();
+
+    if !verify_closed_rings(&outers) {
+        // For clipped multipolygons, some loops may not close perfectly
+        // Instead of force-closing with straight lines (which creates wedges),
+        // filter out unclosed loops and only render the properly closed ones
+
+        // Filter: Keep only loops that are already closed OR can be closed within 1 block
+        outers.retain(|loop_nodes| {
+            if loop_nodes.len() < 3 {
+                return false;
+            }
+            let first = &loop_nodes[0];
+            let last = loop_nodes.last().unwrap();
+            let dx = (first.x - last.x).abs();
+            let dz = (first.z - last.z).abs();
+
+            // Keep if already closed by ID or endpoints are within 1 block
+            first.id == last.id || (dx <= 1 && dz <= 1)
+        });
+
+        // Now close the remaining loops that are within 1 block tolerance
+        for loop_nodes in outers.iter_mut() {
+            let first = loop_nodes[0].clone();
+            let last_idx = loop_nodes.len() - 1;
+            if loop_nodes[0].id != loop_nodes[last_idx].id {
+                // Endpoints are close (within tolerance), close the loop
+                loop_nodes.push(first);
+            }
         }
 
-        merge_loopy_loops(&mut inners);
-        if !verify_loopy_loops(&inners) {
-            // If inners are invalid, process outer without inners
-            let empty_inners: Vec<Vec<ProcessedNode>> = vec![];
-            let mut temp_inners = empty_inners;
-            merge_loopy_loops(&mut temp_inners);
-
-            let (min_x, min_z) = editor.get_min_coords();
-            let (max_x, max_z) = editor.get_max_coords();
-            let individual_outers_xz: Vec<Vec<XZPoint>> = individual_outers
-                .iter()
-                .map(|x| x.iter().map(|y| y.xz()).collect::<Vec<_>>())
-                .collect();
-            let empty_inners_xz: Vec<Vec<XZPoint>> = vec![];
-
-            inverse_floodfill(
-                min_x,
-                min_z,
-                max_x,
-                max_z,
-                individual_outers_xz,
-                empty_inners_xz,
-                editor,
-                start_time,
-            );
-            continue;
+        // If no valid outer loops remain, skip the relation
+        if outers.is_empty() {
+            return;
         }
 
-        let (min_x, min_z) = editor.get_min_coords();
-        let (max_x, max_z) = editor.get_max_coords();
-        let individual_outers_xz: Vec<Vec<XZPoint>> = individual_outers
-            .iter()
-            .map(|x| x.iter().map(|y| y.xz()).collect::<Vec<_>>())
-            .collect();
-        let inners_xz: Vec<Vec<XZPoint>> = inners
-            .iter()
-            .map(|x| x.iter().map(|y| y.xz()).collect::<Vec<_>>())
-            .collect();
-
-        inverse_floodfill(
-            min_x,
-            min_z,
-            max_x,
-            max_z,
-            individual_outers_xz,
-            inners_xz,
-            editor,
-            start_time,
-        );
+        // Verify again after filtering and closing
+        if !verify_closed_rings(&outers) {
+            println!("Skipping relation {} due to invalid polygon", element.id);
+            return;
+        }
     }
+
+    merge_way_segments(&mut inners);
+    if !verify_closed_rings(&inners) {
+        println!("Skipping relation {} due to invalid polygon", element.id);
+        return;
+    }
+
+    generate_water_areas(editor, &outers, &inners);
 }
 
-// Merges ways that share nodes into full loops
-fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
+fn generate_water_areas(
+    editor: &mut WorldEditor,
+    outers: &[Vec<ProcessedNode>],
+    inners: &[Vec<ProcessedNode>],
+) {
+    // Calculate polygon bounding box to limit fill area
+    let mut poly_min_x = i32::MAX;
+    let mut poly_min_z = i32::MAX;
+    let mut poly_max_x = i32::MIN;
+    let mut poly_max_z = i32::MIN;
+
+    for outer in outers {
+        for node in outer {
+            poly_min_x = poly_min_x.min(node.x);
+            poly_min_z = poly_min_z.min(node.z);
+            poly_max_x = poly_max_x.max(node.x);
+            poly_max_z = poly_max_z.max(node.z);
+        }
+    }
+
+    // If no valid bounds, nothing to fill
+    if poly_min_x == i32::MAX || poly_max_x == i32::MIN {
+        return;
+    }
+
+    // Clamp to world bounds just in case
+    let (world_min_x, world_min_z) = editor.get_min_coords();
+    let (world_max_x, world_max_z) = editor.get_max_coords();
+    let min_x = poly_min_x.max(world_min_x);
+    let min_z = poly_min_z.max(world_min_z);
+    let max_x = poly_max_x.min(world_max_x);
+    let max_z = poly_max_z.min(world_max_z);
+
+    let outers_xz: Vec<Vec<XZPoint>> = outers
+        .iter()
+        .map(|x| x.iter().map(|y| y.xz()).collect::<Vec<_>>())
+        .collect();
+    let inners_xz: Vec<Vec<XZPoint>> = inners
+        .iter()
+        .map(|x| x.iter().map(|y| y.xz()).collect::<Vec<_>>())
+        .collect();
+
+    inverse_floodfill(min_x, min_z, max_x, max_z, outers_xz, inners_xz, editor);
+}
+
+/// Merges way segments that share endpoints into closed rings.
+fn merge_way_segments(rings: &mut Vec<Vec<ProcessedNode>>) {
     let mut removed: Vec<usize> = vec![];
     let mut merged: Vec<Vec<ProcessedNode>> = vec![];
 
-    for i in 0..loops.len() {
-        for j in 0..loops.len() {
+    // Match nodes by ID or proximity (handles synthetic nodes from bbox clipping)
+    let nodes_match = |a: &ProcessedNode, b: &ProcessedNode| -> bool {
+        if a.id == b.id {
+            return true;
+        }
+        let dx = (a.x - b.x).abs();
+        let dz = (a.z - b.z).abs();
+        dx <= 1 && dz <= 1
+    };
+
+    for i in 0..rings.len() {
+        for j in 0..rings.len() {
             if i == j {
                 continue;
             }
@@ -117,20 +191,29 @@ fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
                 continue;
             }
 
-            let x: &Vec<ProcessedNode> = &loops[i];
-            let y: &Vec<ProcessedNode> = &loops[j];
+            let x: &Vec<ProcessedNode> = &rings[i];
+            let y: &Vec<ProcessedNode> = &rings[j];
 
-            // it's looped already
-            if x[0].id == x.last().unwrap().id {
+            // Skip empty rings (can happen after clipping)
+            if x.is_empty() || y.is_empty() {
                 continue;
             }
 
-            // it's looped already
-            if y[0].id == y.last().unwrap().id {
+            let x_first = &x[0];
+            let x_last = x.last().unwrap();
+            let y_first = &y[0];
+            let y_last = y.last().unwrap();
+
+            // Skip already-closed rings
+            if nodes_match(x_first, x_last) {
                 continue;
             }
 
-            if x[0].id == y[0].id {
+            if nodes_match(y_first, y_last) {
+                continue;
+            }
+
+            if nodes_match(x_first, y_first) {
                 removed.push(i);
                 removed.push(j);
 
@@ -138,7 +221,7 @@ fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
                 x.reverse();
                 x.extend(y.iter().skip(1).cloned());
                 merged.push(x);
-            } else if x.last().unwrap().id == y.last().unwrap().id {
+            } else if nodes_match(x_last, y_last) {
                 removed.push(i);
                 removed.push(j);
 
@@ -146,7 +229,7 @@ fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
                 x.extend(y.iter().rev().skip(1).cloned());
 
                 merged.push(x);
-            } else if x[0].id == y.last().unwrap().id {
+            } else if nodes_match(x_first, y_last) {
                 removed.push(i);
                 removed.push(j);
 
@@ -154,7 +237,7 @@ fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
                 y.extend(x.iter().skip(1).cloned());
 
                 merged.push(y);
-            } else if x.last().unwrap().id == y[0].id {
+            } else if nodes_match(x_last, y_first) {
                 removed.push(i);
                 removed.push(j);
 
@@ -169,24 +252,35 @@ fn merge_loopy_loops(loops: &mut Vec<Vec<ProcessedNode>>) {
     removed.sort();
 
     for r in removed.iter().rev() {
-        loops.remove(*r);
+        rings.remove(*r);
     }
 
     let merged_len: usize = merged.len();
     for m in merged {
-        loops.push(m);
+        rings.push(m);
     }
 
     if merged_len > 0 {
-        merge_loopy_loops(loops);
+        merge_way_segments(rings);
     }
 }
 
-fn verify_loopy_loops(loops: &[Vec<ProcessedNode>]) -> bool {
-    let mut valid: bool = true;
-    for l in loops {
-        if l[0].id != l.last().unwrap().id {
-            eprintln!("WARN: Disconnected loop");
+/// Verifies all rings are properly closed (first node matches last).
+fn verify_closed_rings(rings: &[Vec<ProcessedNode>]) -> bool {
+    let mut valid = true;
+    for ring in rings {
+        let first = &ring[0];
+        let last = ring.last().unwrap();
+
+        // Check if ring is closed (by ID or proximity)
+        let is_closed = first.id == last.id || {
+            let dx = (first.x - last.x).abs();
+            let dz = (first.z - last.z).abs();
+            dx <= 1 && dz <= 1
+        };
+
+        if !is_closed {
+            eprintln!("WARN: Disconnected ring");
             valid = false;
         }
     }
@@ -206,8 +300,8 @@ fn inverse_floodfill(
     outers: Vec<Vec<XZPoint>>,
     inners: Vec<Vec<XZPoint>>,
     editor: &mut WorldEditor,
-    start_time: Instant,
 ) {
+    // Convert to geo Polygons with normalized winding order
     let inners: Vec<_> = inners
         .into_iter()
         .map(|x| {
@@ -219,6 +313,7 @@ fn inverse_floodfill(
                 ),
                 vec![],
             )
+            .orient(Direction::Default)
         })
         .collect();
 
@@ -233,17 +328,11 @@ fn inverse_floodfill(
                 ),
                 vec![],
             )
+            .orient(Direction::Default)
         })
         .collect();
 
-    inverse_floodfill_recursive(
-        (min_x, min_z),
-        (max_x, max_z),
-        &outers,
-        &inners,
-        editor,
-        start_time,
-    );
+    inverse_floodfill_recursive((min_x, min_z), (max_x, max_z), &outers, &inners, editor);
 }
 
 fn inverse_floodfill_recursive(
@@ -252,12 +341,11 @@ fn inverse_floodfill_recursive(
     outers: &[Polygon],
     inners: &[Polygon],
     editor: &mut WorldEditor,
-    start_time: Instant,
 ) {
-    // Check if we've exceeded 25 seconds
-    if start_time.elapsed().as_secs() > 25 {
-        println!("Water area generation exceeded 25 seconds, continuing anyway");
-    }
+    // Check if we've exceeded 40 seconds
+    // if start_time.elapsed().as_secs() > 40 {
+    //     println!("Water area generation exceeded 40 seconds, continuing anyway");
+    // }
 
     const ITERATIVE_THRES: i64 = 10_000;
 
@@ -312,7 +400,6 @@ fn inverse_floodfill_recursive(
                 &outers_intersects,
                 &inners_intersects,
                 editor,
-                start_time,
             );
         }
     }

src/elevation_data.rs

@@ -1,11 +1,12 @@
 use crate::coordinate_system::{geographic::LLBBox, transformation::geo_distance};
+#[cfg(feature = "gui")]
+use crate::telemetry::{send_log, LogLevel};
 use image::Rgb;
-use std::path::Path;
+use rayon::prelude::*;
+use std::path::{Path, PathBuf};
 
 /// Maximum Y coordinate in Minecraft (build height limit)
 const MAX_Y: i32 = 319;
-/// Scale factor for converting real elevation to Minecraft heights
-const BASE_HEIGHT_SCALE: f64 = 0.7;
 /// AWS S3 Terrarium tiles endpoint (no API key required)
 const AWS_TERRARIUM_URL: &str =
     "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png";
@@ -15,6 +16,8 @@ const TERRARIUM_OFFSET: f64 = 32768.0;
 const MIN_ZOOM: u8 = 10;
 /// Maximum zoom level for terrain tiles
 const MAX_ZOOM: u8 = 15;
+/// Maximum concurrent tile downloads to be respectful to AWS
+const MAX_CONCURRENT_DOWNLOADS: usize = 8;
 
 /// Holds processed elevation data and metadata
 #[derive(Clone)]
@@ -27,6 +30,11 @@ pub struct ElevationData {
     pub(crate) height: usize,
 }
 
+/// RGB image buffer type for elevation tiles
+type TileImage = image::ImageBuffer<Rgb<u8>, Vec<u8>>;
+/// Result type for tile download operations: ((tile_x, tile_y), image) or error
+type TileDownloadResult = Result<((u32, u32), TileImage), String>;
+
 /// Calculates appropriate zoom level for the given bounding box
 fn calculate_zoom_level(bbox: &LLBBox) -> u8 {
     let lat_diff: f64 = (bbox.max().lat() - bbox.min().lat()).abs();
@@ -44,6 +52,110 @@ fn lat_lng_to_tile(lat: f64, lng: f64, zoom: u8) -> (u32, u32) {
     (x, y)
 }
 
+/// Downloads a tile from AWS Terrain Tiles service
+fn download_tile(
+    client: &reqwest::blocking::Client,
+    tile_x: u32,
+    tile_y: u32,
+    zoom: u8,
+    tile_path: &Path,
+) -> Result<image::ImageBuffer<Rgb<u8>, Vec<u8>>, String> {
+    println!("Fetching tile x={tile_x},y={tile_y},z={zoom} from AWS Terrain Tiles");
+    let url: String = AWS_TERRARIUM_URL
+        .replace("{z}", &zoom.to_string())
+        .replace("{x}", &tile_x.to_string())
+        .replace("{y}", &tile_y.to_string());
+
+    let response = client.get(&url).send().map_err(|e| e.to_string())?;
+    response.error_for_status_ref().map_err(|e| e.to_string())?;
+    let bytes = response.bytes().map_err(|e| e.to_string())?;
+    std::fs::write(tile_path, &bytes).map_err(|e| e.to_string())?;
+    let img = image::load_from_memory(&bytes).map_err(|e| e.to_string())?;
+    Ok(img.to_rgb8())
+}
+
+/// Fetches a tile from cache or downloads it if not available
+/// Note: In parallel execution, multiple threads may attempt to download the same tile
+/// if it's missing or corrupted. This is harmless (just wastes some bandwidth) as
+/// file writes are atomic at the OS level.
+fn fetch_or_load_tile(
+    client: &reqwest::blocking::Client,
+    tile_x: u32,
+    tile_y: u32,
+    zoom: u8,
+    tile_path: &Path,
+) -> Result<image::ImageBuffer<Rgb<u8>, Vec<u8>>, String> {
+    if tile_path.exists() {
+        // Check if the cached file has a reasonable size (PNG files should be at least a few KB)
+        let file_size = std::fs::metadata(tile_path).map(|m| m.len()).unwrap_or(0);
+
+        if file_size < 1000 {
+            eprintln!(
+                "Warning: Cached tile at {} appears to be too small ({} bytes). Refetching tile.",
+                tile_path.display(),
+                file_size
+            );
+            #[cfg(feature = "gui")]
+            send_log(
+                LogLevel::Warning,
+                "Cached tile appears too small, refetching.",
+            );
+
+            // Remove the potentially corrupted file
+            if let Err(e) = std::fs::remove_file(tile_path) {
+                eprintln!("Warning: Failed to remove corrupted tile file: {e}");
+                #[cfg(feature = "gui")]
+                send_log(
+                    LogLevel::Warning,
+                    "Failed to remove corrupted tile file during refetching.",
+                );
+            }
+
+            // Re-download the tile
+            return download_tile(client, tile_x, tile_y, zoom, tile_path);
+        }
+
+        // Try to load cached tile, but handle corruption gracefully
+        match image::open(tile_path) {
+            Ok(img) => {
+                println!(
+                    "Loading cached tile x={tile_x},y={tile_y},z={zoom} from {}",
+                    tile_path.display()
+                );
+                Ok(img.to_rgb8())
+            }
+            Err(e) => {
+                eprintln!(
+                    "Cached tile at {} is corrupted or invalid: {}. Re-downloading...",
+                    tile_path.display(),
+                    e
+                );
+                #[cfg(feature = "gui")]
+                send_log(
+                    LogLevel::Warning,
+                    "Cached tile is corrupted or invalid. Re-downloading...",
+                );
+
+                // Remove the corrupted file
+                if let Err(e) = std::fs::remove_file(tile_path) {
+                    eprintln!("Warning: Failed to remove corrupted tile file: {e}");
+                    #[cfg(feature = "gui")]
+                    send_log(
+                        LogLevel::Warning,
+                        "Failed to remove corrupted tile file during re-download.",
+                    );
+                }
+
+                // Re-download the tile
+                download_tile(client, tile_x, tile_y, zoom, tile_path)
+            }
+        }
+    } else {
+        // Download the tile for the first time
+        download_tile(client, tile_x, tile_y, zoom, tile_path)
+    }
+}
+
 pub fn fetch_elevation_data(
     bbox: &LLBBox,
     scale: f64,
@@ -67,51 +179,68 @@ pub fn fetch_elevation_data(
     let mut height_grid: Vec<Vec<f64>> = vec![vec![f64::NAN; grid_width]; grid_height];
     let mut extreme_values_found = Vec::new(); // Track extreme values for debugging
 
-    let client: reqwest::blocking::Client = reqwest::blocking::Client::new();
-
-    let tile_cache_dir = Path::new("./arnis-tile-cache");
+    let tile_cache_dir = PathBuf::from("./arnis-tile-cache");
     if !tile_cache_dir.exists() {
-        std::fs::create_dir_all(tile_cache_dir)?;
+        std::fs::create_dir_all(&tile_cache_dir)?;
     }
 
-    // Fetch and process each tile
-    for (tile_x, tile_y) in &tiles {
-        // Check if tile is already cached
-        let tile_path = tile_cache_dir.join(format!("z{zoom}_x{tile_x}_y{tile_y}.png"));
+    // Create a shared HTTP client for connection pooling
+    let client = reqwest::blocking::Client::new();
 
-        let rgb_img: image::ImageBuffer<Rgb<u8>, Vec<u8>> = if tile_path.exists() {
-            println!(
-                "Loading cached tile x={tile_x},y={tile_y},z={zoom} from {}",
-                tile_path.display()
-            );
-            let img: image::DynamicImage = image::open(&tile_path)?;
-            img.to_rgb8()
-        } else {
-            // AWS Terrain Tiles don't require an API key
-            println!("Fetching tile x={tile_x},y={tile_y},z={zoom} from AWS Terrain Tiles");
-            let url: String = AWS_TERRARIUM_URL
-                .replace("{z}", &zoom.to_string())
-                .replace("{x}", &tile_x.to_string())
-                .replace("{y}", &tile_y.to_string());
+    // Download tiles in parallel with limited concurrency to be respectful to AWS
+    let num_tiles = tiles.len();
+    println!(
+        "Downloading {num_tiles} elevation tiles (up to {MAX_CONCURRENT_DOWNLOADS} concurrent)..."
+    );
 
-            let response: reqwest::blocking::Response = client.get(&url).send()?;
-            response.error_for_status_ref()?;
-            let bytes = response.bytes()?;
-            std::fs::write(&tile_path, &bytes)?;
-            let img: image::DynamicImage = image::load_from_memory(&bytes)?;
-            img.to_rgb8()
-        };
+    // Use a custom thread pool to limit concurrent downloads
+    let thread_pool = rayon::ThreadPoolBuilder::new()
+        .num_threads(MAX_CONCURRENT_DOWNLOADS)
+        .build()
+        .map_err(|e| format!("Failed to create thread pool: {e}"))?;
 
+    let downloaded_tiles: Vec<TileDownloadResult> = thread_pool.install(|| {
+        tiles
+            .par_iter()
+            .map(|(tile_x, tile_y)| {
+                let tile_path = tile_cache_dir.join(format!("z{zoom}_x{tile_x}_y{tile_y}.png"));
+
+                let rgb_img = fetch_or_load_tile(&client, *tile_x, *tile_y, zoom, &tile_path)?;
+                Ok(((*tile_x, *tile_y), rgb_img))
+            })
+            .collect()
+    });
+
+    // Check for any download errors
+    let mut successful_tiles = Vec::new();
+    for result in downloaded_tiles {
+        match result {
+            Ok(tile_data) => successful_tiles.push(tile_data),
+            Err(e) => {
+                eprintln!("Warning: Failed to download tile: {e}");
+                #[cfg(feature = "gui")]
+                send_log(
+                    LogLevel::Warning,
+                    &format!("Failed to download elevation tile: {e}"),
+                );
+            }
+        }
+    }
+
+    println!("Processing {} elevation tiles...", successful_tiles.len());
+
+    // Process tiles sequentially (writes to shared height_grid)
+    for ((tile_x, tile_y), rgb_img) in successful_tiles {
         // Only process pixels that fall within the requested bbox
         for (y, row) in rgb_img.rows().enumerate() {
             for (x, pixel) in row.enumerate() {
                 // Convert tile pixel coordinates back to geographic coordinates
-                let pixel_lng = ((*tile_x as f64 + x as f64 / 256.0) / (2.0_f64.powi(zoom as i32)))
+                let pixel_lng = ((tile_x as f64 + x as f64 / 256.0) / (2.0_f64.powi(zoom as i32)))
                     * 360.0
                     - 180.0;
                 let pixel_lat_rad = std::f64::consts::PI
                     * (1.0
-                        - 2.0 * (*tile_y as f64 + y as f64 / 256.0) / (2.0_f64.powi(zoom as i32)));
+                        - 2.0 * (tile_y as f64 + y as f64 / 256.0) / (2.0_f64.powi(zoom as i32)));
                 let pixel_lat = pixel_lat_rad.sinh().atan().to_degrees();
 
                 // Skip pixels outside the requested bounding box
@@ -172,34 +301,33 @@ pub fn fetch_elevation_data(
     filter_elevation_outliers(&mut height_grid);
 
     // Calculate blur sigma based on grid resolution
-    // Reference points for tuning:
-    const SMALL_GRID_REF: f64 = 100.0; // Reference grid size
-    const SMALL_SIGMA_REF: f64 = 15.0; // Sigma for 100x100 grid
-    const LARGE_GRID_REF: f64 = 1000.0; // Reference grid size
-    const LARGE_SIGMA_REF: f64 = 7.0; // Sigma for 1000x1000 grid
+    // Use sqrt scaling to maintain consistent relative smoothing across different area sizes.
+    // This prevents larger generation areas from appearing noisier than smaller ones.
+    // Reference: 100x100 grid uses sigma=5 (5% relative blur)
+    const BASE_GRID_REF: f64 = 100.0;
+    const BASE_SIGMA_REF: f64 = 5.0;
 
     let grid_size: f64 = (grid_width.min(grid_height) as f64).max(1.0);
 
-    let sigma: f64 = if grid_size <= SMALL_GRID_REF {
-        // Linear scaling for small grids
-        SMALL_SIGMA_REF * (grid_size / SMALL_GRID_REF)
-    } else {
-        // Logarithmic scaling for larger grids
-        let ln_small: f64 = SMALL_GRID_REF.ln();
-        let ln_large: f64 = LARGE_GRID_REF.ln();
-        let log_grid_size: f64 = grid_size.ln();
-        let t: f64 = (log_grid_size - ln_small) / (ln_large - ln_small);
-        SMALL_SIGMA_REF + t * (LARGE_SIGMA_REF - SMALL_SIGMA_REF)
-    };
+    // Sqrt scaling provides a good balance:
+    // - 100x100: sigma = 5 (5% relative)
+    // - 500x500: sigma ≈ 11.2 (2.2% relative)
+    // - 1000x1000: sigma ≈ 15.8 (1.6% relative)
+    // This smooths terrain proportionally while preserving more detail.
+    let sigma: f64 = BASE_SIGMA_REF * (grid_size / BASE_GRID_REF).sqrt();
 
-    /* eprintln!(
-        "Grid: {}x{}, Blur sigma: {:.2}",
-        grid_width, grid_height, sigma
-    ); */
+    //let blur_percentage: f64 = (sigma / grid_size) * 100.0;
+    /*eprintln!(
+        "Elevation blur: grid={}x{}, sigma={:.2}, blur_percentage={:.2}%",
+        grid_width, grid_height, sigma, blur_percentage
+    );*/
 
     // Continue with the existing blur and conversion to Minecraft heights...
     let blurred_heights: Vec<Vec<f64>> = apply_gaussian_blur(&height_grid, sigma);
 
+    // Release raw height grid
+    drop(height_grid);
+
     let mut mc_heights: Vec<Vec<i32>> = Vec::with_capacity(blurred_heights.len());
 
     // Find min/max in raw data
@@ -223,7 +351,7 @@ pub fn fetch_elevation_data(
         }
     }
 
-    eprintln!("Height data range: {min_height} to {max_height} m");
+    //eprintln!("Height data range: {min_height} to {max_height} m");
     if extreme_low_count > 0 {
         eprintln!(
             "WARNING: Found {extreme_low_count} pixels with extremely low elevations (< -1000m)"
@@ -236,35 +364,58 @@ pub fn fetch_elevation_data(
     }
 
     let height_range: f64 = max_height - min_height;
-    // Apply scale factor to height scaling
-    let mut height_scale: f64 = BASE_HEIGHT_SCALE * scale.sqrt(); // sqrt to make height scaling less extreme
-    let mut scaled_range: f64 = height_range * height_scale;
 
-    // Adaptive scaling: ensure we don't exceed reasonable Y range
-    let available_y_range = (MAX_Y - ground_level) as f64;
-    let safety_margin = 0.9; // Use 90% of available range
-    let max_allowed_range = available_y_range * safety_margin;
+    // Realistic height scaling: 1 meter of real elevation = scale blocks in Minecraft
+    // At scale=1.0, 1 meter = 1 block (realistic 1:1 mapping)
+    // At scale=2.0, 1 meter = 2 blocks (exaggerated for larger worlds)
+    let ideal_scaled_range: f64 = height_range * scale;
 
-    if scaled_range > max_allowed_range {
-        let adjustment_factor = max_allowed_range / scaled_range;
-        height_scale *= adjustment_factor;
-        scaled_range = height_range * height_scale;
+    // Calculate available Y range in Minecraft (from ground_level to MAX_Y)
+    // Leave a buffer at the top for buildings, trees, and other structures
+    const TERRAIN_HEIGHT_BUFFER: i32 = 15;
+    let available_y_range: f64 = (MAX_Y - TERRAIN_HEIGHT_BUFFER - ground_level) as f64;
+
+    // Determine final height scale:
+    // - Use realistic 1:1 (times scale) if terrain fits within Minecraft limits
+    // - Only compress if the terrain would exceed the build height
+    let scaled_range: f64 = if ideal_scaled_range <= available_y_range {
+        // Terrain fits! Use realistic scaling
         eprintln!(
-            "Height range too large, applying scaling adjustment factor: {adjustment_factor:.3}"
+            "Realistic elevation: {:.1}m range fits in {} available blocks",
+            height_range, available_y_range as i32
         );
-        eprintln!("Adjusted scaled range: {scaled_range:.1} blocks");
-    }
+        ideal_scaled_range
+    } else {
+        // Terrain too tall, compress to fit within Minecraft limits
+        let compression_factor: f64 = available_y_range / height_range;
+        let compressed_range: f64 = height_range * compression_factor;
+        eprintln!(
+            "Elevation compressed: {:.1}m range -> {:.0} blocks ({:.2}:1 ratio, 1 block = {:.2}m)",
+            height_range,
+            compressed_range,
+            height_range / compressed_range,
+            compressed_range / height_range
+        );
+        compressed_range
+    };
 
     // Convert to scaled Minecraft Y coordinates
+    // Lowest real elevation maps to ground_level, highest maps to ground_level + scaled_range
     for row in blurred_heights {
         let mc_row: Vec<i32> = row
             .iter()
             .map(|&h| {
-                // Scale the height differences
-                let relative_height: f64 = (h - min_height) / height_range;
+                // Calculate relative position within the elevation range (0.0 to 1.0)
+                let relative_height: f64 = if height_range > 0.0 {
+                    (h - min_height) / height_range
+                } else {
+                    0.0
+                };
+                // Scale to Minecraft blocks and add to ground level
                 let scaled_height: f64 = relative_height * scaled_range;
-                // With terrain enabled, ground_level is used as the MIN_Y for terrain
-                ((ground_level as f64 + scaled_height).round() as i32).clamp(ground_level, MAX_Y)
+                // Clamp to valid Minecraft Y range (leave buffer at top for structures)
+                ((ground_level as f64 + scaled_height).round() as i32)
+                    .clamp(ground_level, MAX_Y - TERRAIN_HEIGHT_BUFFER)
             })
             .collect();
         mc_heights.push(mc_row);
@@ -278,7 +429,7 @@ pub fn fetch_elevation_data(
             max_block_height = max_block_height.max(height);
         }
     }
-    eprintln!("Minecraft height data range: {min_block_height} to {max_block_height} blocks");
+    //eprintln!("Minecraft height data range: {min_block_height} to {max_block_height} blocks");
 
     Ok(ElevationData {
         heights: mc_heights,
@@ -438,7 +589,7 @@ fn filter_elevation_outliers(height_grid: &mut [Vec<f64>]) {
     let min_reasonable = all_heights[p1_idx];
     let max_reasonable = all_heights[p99_idx];
 
-    eprintln!("Filtering outliers outside range: {min_reasonable:.1}m to {max_reasonable:.1}m");
+    //eprintln!("Filtering outliers outside range: {min_reasonable:.1}m to {max_reasonable:.1}m");
 
     let mut outliers_filtered = 0;
 
@@ -453,7 +604,7 @@ fn filter_elevation_outliers(height_grid: &mut [Vec<f64>]) {
     }
 
     if outliers_filtered > 0 {
-        eprintln!("Filtered {outliers_filtered} elevation outliers, interpolating replacements...");
+        //eprintln!("Filtered {outliers_filtered} elevation outliers, interpolating replacements...");
         // Re-run the NaN filling to interpolate the filtered values
         fill_nan_values(height_grid);
     }

src/floodfill.rs

@@ -71,7 +71,7 @@ fn optimized_flood_fill_area(
 
     for z in (min_z..=max_z).step_by(step_z as usize) {
         for x in (min_x..=max_x).step_by(step_x as usize) {
-            // Fast timeout check - only every few iterations
+            // Fast timeout check, only every few iterations
             if filled_area.len() % 100 == 0 {
                 if let Some(timeout) = timeout {
                     if start_time.elapsed() > *timeout {
@@ -160,11 +160,10 @@ fn original_flood_fill_area(
     for z in (min_z..=max_z).step_by(step_z as usize) {
         for x in (min_x..=max_x).step_by(step_x as usize) {
             // Reduced timeout checking frequency for better performance
-            if global_visited.len() % 200 == 0 {
-                if let Some(timeout) = timeout {
-                    if &start_time.elapsed() > timeout {
-                        return filled_area;
-                    }
+            // Use manual % check since is_multiple_of() is unstable on stable Rust
+            if let Some(timeout) = timeout {
+                if &start_time.elapsed() > timeout {
+                    return filled_area;
                 }
             }
 

src/floodfill_cache.rs

@@ -0,0 +1,338 @@
+//! Pre-computed flood fill cache for parallel polygon filling.
+//!
+//! This module provides a way to pre-compute all flood fill operations in parallel
+//! before the main element processing loop, then retrieve cached results during
+//! sequential processing.
+
+use crate::coordinate_system::cartesian::XZBBox;
+use crate::floodfill::flood_fill_area;
+use crate::osm_parser::{ProcessedElement, ProcessedMemberRole, ProcessedWay};
+use fnv::FnvHashMap;
+use rayon::prelude::*;
+use std::time::Duration;
+
+/// A memory-efficient bitmap for storing building footprint coordinates.
+///
+/// Instead of storing each coordinate individually (~24 bytes per entry in a HashSet),
+/// this uses 1 bit per coordinate in the world bounds, reducing memory usage by ~200x.
+///
+/// For a world of size W x H blocks, the bitmap uses only (W * H) / 8 bytes.
+pub struct BuildingFootprintBitmap {
+    /// The bitmap data, where each bit represents one (x, z) coordinate
+    bits: Vec<u8>,
+    /// Minimum x coordinate (offset for indexing)
+    min_x: i32,
+    /// Minimum z coordinate (offset for indexing)
+    min_z: i32,
+    /// Width of the world (max_x - min_x + 1)
+    width: usize,
+    /// Height of the world (max_z - min_z + 1)
+    height: usize,
+    /// Number of coordinates marked as building footprints
+    count: usize,
+}
+
+impl BuildingFootprintBitmap {
+    /// Creates a new empty bitmap covering the given world bounds.
+    pub fn new(xzbbox: &XZBBox) -> Self {
+        let min_x = xzbbox.min_x();
+        let min_z = xzbbox.min_z();
+        // Use i64 to avoid overflow when world spans more than i32::MAX in either dimension
+        let width = (i64::from(xzbbox.max_x()) - i64::from(min_x) + 1) as usize;
+        let height = (i64::from(xzbbox.max_z()) - i64::from(min_z) + 1) as usize;
+
+        // Calculate number of bytes needed (round up to nearest byte)
+        let total_bits = width
+            .checked_mul(height)
+            .expect("BuildingFootprintBitmap: world size too large (width * height overflowed)");
+        let num_bytes = total_bits.div_ceil(8);
+
+        Self {
+            bits: vec![0u8; num_bytes],
+            min_x,
+            min_z,
+            width,
+            height,
+            count: 0,
+        }
+    }
+
+    /// Converts (x, z) coordinate to bit index, returning None if out of bounds.
+    #[inline]
+    fn coord_to_index(&self, x: i32, z: i32) -> Option<usize> {
+        // Use i64 arithmetic to avoid overflow when coordinates span large ranges
+        let local_x = i64::from(x) - i64::from(self.min_x);
+        let local_z = i64::from(z) - i64::from(self.min_z);
+
+        if local_x < 0 || local_z < 0 {
+            return None;
+        }
+
+        let local_x = local_x as usize;
+        let local_z = local_z as usize;
+
+        if local_x >= self.width || local_z >= self.height {
+            return None;
+        }
+
+        // Safe: bounds checks above ensure this won't overflow (max = total_bits - 1)
+        Some(local_z * self.width + local_x)
+    }
+
+    /// Sets a coordinate as part of a building footprint.
+    #[inline]
+    pub fn set(&mut self, x: i32, z: i32) {
+        if let Some(bit_index) = self.coord_to_index(x, z) {
+            let byte_index = bit_index / 8;
+            let bit_offset = bit_index % 8;
+
+            // Safety: coord_to_index already validates bounds, so byte_index is always valid
+            let mask = 1u8 << bit_offset;
+            // Only increment count if bit wasn't already set
+            if self.bits[byte_index] & mask == 0 {
+                self.bits[byte_index] |= mask;
+                self.count += 1;
+            }
+        }
+    }
+
+    /// Checks if a coordinate is part of a building footprint.
+    #[inline]
+    pub fn contains(&self, x: i32, z: i32) -> bool {
+        if let Some(bit_index) = self.coord_to_index(x, z) {
+            let byte_index = bit_index / 8;
+            let bit_offset = bit_index % 8;
+
+            // Safety: coord_to_index already validates bounds, so byte_index is always valid
+            return (self.bits[byte_index] >> bit_offset) & 1 == 1;
+        }
+        false
+    }
+
+    /// Returns true if no coordinates are marked.
+    #[must_use]
+    #[allow(dead_code)] // Standard API method for collection-like types
+    pub fn is_empty(&self) -> bool {
+        self.count == 0
+    }
+}
+
+/// A cache of pre-computed flood fill results, keyed by element ID.
+pub struct FloodFillCache {
+    /// Cached results: element_id -> filled coordinates
+    way_cache: FnvHashMap<u64, Vec<(i32, i32)>>,
+}
+
+impl FloodFillCache {
+    /// Creates an empty cache.
+    pub fn new() -> Self {
+        Self {
+            way_cache: FnvHashMap::default(),
+        }
+    }
+
+    /// Pre-computes flood fills for all elements that need them.
+    ///
+    /// This runs in parallel using Rayon, taking advantage of multiple CPU cores.
+    pub fn precompute(elements: &[ProcessedElement], timeout: Option<&Duration>) -> Self {
+        // Collect all ways that need flood fill
+        let ways_needing_fill: Vec<&ProcessedWay> = elements
+            .iter()
+            .filter_map(|el| match el {
+                ProcessedElement::Way(way) => {
+                    if Self::way_needs_flood_fill(way) {
+                        Some(way)
+                    } else {
+                        None
+                    }
+                }
+                _ => None,
+            })
+            .collect();
+
+        // Compute all way flood fills in parallel
+        let way_results: Vec<(u64, Vec<(i32, i32)>)> = ways_needing_fill
+            .par_iter()
+            .map(|way| {
+                let polygon_coords: Vec<(i32, i32)> =
+                    way.nodes.iter().map(|n| (n.x, n.z)).collect();
+                let filled = flood_fill_area(&polygon_coords, timeout);
+                (way.id, filled)
+            })
+            .collect();
+
+        // Build the cache
+        let mut cache = Self::new();
+        for (id, filled) in way_results {
+            cache.way_cache.insert(id, filled);
+        }
+
+        cache
+    }
+
+    /// Gets cached flood fill result for a way, or computes it if not cached.
+    ///
+    /// Note: Combined ways created from relations (e.g., in `generate_natural_from_relation`)
+    /// will miss the cache and fall back to on-demand computation. This is by design,
+    /// these synthetic ways don't exist in the original element list and have relation IDs
+    /// rather than way IDs. The individual member ways are still cached.
+    pub fn get_or_compute(
+        &self,
+        way: &ProcessedWay,
+        timeout: Option<&Duration>,
+    ) -> Vec<(i32, i32)> {
+        if let Some(cached) = self.way_cache.get(&way.id) {
+            // Clone is intentional: each result is typically accessed once during
+            // sequential processing, so the cost is acceptable vs Arc complexity
+            cached.clone()
+        } else {
+            // Fallback: compute on demand for synthetic/combined ways from relations
+            let polygon_coords: Vec<(i32, i32)> = way.nodes.iter().map(|n| (n.x, n.z)).collect();
+            flood_fill_area(&polygon_coords, timeout)
+        }
+    }
+
+    /// Gets cached flood fill result for a ProcessedElement (Way only).
+    /// For Nodes/Relations, returns empty vec.
+    pub fn get_or_compute_element(
+        &self,
+        element: &ProcessedElement,
+        timeout: Option<&Duration>,
+    ) -> Vec<(i32, i32)> {
+        match element {
+            ProcessedElement::Way(way) => self.get_or_compute(way, timeout),
+            _ => Vec::new(),
+        }
+    }
+
+    /// Determines if a way element needs flood fill based on its tags.
+    ///
+    /// This checks for tag presence (not specific values) because:
+    /// - Only some values within each tag type actually use flood fill
+    /// - But caching extra results is harmless (small memory overhead)
+    /// - And avoids duplicating value-checking logic from processors
+    ///
+    /// Covered cases:
+    /// - building/building:part -> buildings::generate_buildings (includes bridge)
+    /// - landuse -> landuse::generate_landuse
+    /// - leisure -> leisure::generate_leisure
+    /// - amenity -> amenities::generate_amenities
+    /// - natural (except tree) -> natural::generate_natural
+    /// - highway with area=yes -> highways::generate_highways (area fill)
+    fn way_needs_flood_fill(way: &ProcessedWay) -> bool {
+        way.tags.contains_key("building")
+            || way.tags.contains_key("building:part")
+            || way.tags.contains_key("landuse")
+            || way.tags.contains_key("leisure")
+            || way.tags.contains_key("amenity")
+            || way
+                .tags
+                .get("natural")
+                .map(|v| v != "tree")
+                .unwrap_or(false)
+            // Highway areas (like pedestrian plazas) use flood fill when area=yes
+            || (way.tags.contains_key("highway")
+                && way.tags.get("area").map(|v| v == "yes").unwrap_or(false))
+    }
+
+    /// Collects all building footprint coordinates from the pre-computed cache.
+    ///
+    /// This should be called after precompute() and before elements are processed.
+    /// Returns a memory-efficient bitmap of all (x, z) coordinates that are part of buildings.
+    ///
+    /// The bitmap uses only 1 bit per coordinate in the world bounds, compared to ~24 bytes
+    /// per entry in a HashSet, reducing memory usage by ~200x for large worlds.
+    pub fn collect_building_footprints(
+        &self,
+        elements: &[ProcessedElement],
+        xzbbox: &XZBBox,
+    ) -> BuildingFootprintBitmap {
+        let mut footprints = BuildingFootprintBitmap::new(xzbbox);
+
+        for element in elements {
+            match element {
+                ProcessedElement::Way(way) => {
+                    if way.tags.contains_key("building") || way.tags.contains_key("building:part") {
+                        if let Some(cached) = self.way_cache.get(&way.id) {
+                            for &(x, z) in cached {
+                                footprints.set(x, z);
+                            }
+                        }
+                    }
+                }
+                ProcessedElement::Relation(rel) => {
+                    if rel.tags.contains_key("building") || rel.tags.contains_key("building:part") {
+                        for member in &rel.members {
+                            // Only treat outer members as building footprints.
+                            // Inner members represent courtyards/holes where trees can spawn.
+                            if member.role == ProcessedMemberRole::Outer {
+                                if let Some(cached) = self.way_cache.get(&member.way.id) {
+                                    for &(x, z) in cached {
+                                        footprints.set(x, z);
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+
+        footprints
+    }
+
+    /// Removes a way's cached flood fill result, freeing memory.
+    ///
+    /// Call this after processing an element to release its cached data.
+    pub fn remove_way(&mut self, way_id: u64) {
+        self.way_cache.remove(&way_id);
+    }
+
+    /// Removes all cached flood fill results for ways in a relation.
+    ///
+    /// Relations contain multiple ways, so we need to remove all of them.
+    pub fn remove_relation_ways(&mut self, way_ids: &[u64]) {
+        for &id in way_ids {
+            self.way_cache.remove(&id);
+        }
+    }
+}
+
+impl Default for FloodFillCache {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Configures the global Rayon thread pool with a CPU usage cap.
+///
+/// Call this once at startup before any parallel operations.
+///
+/// # Arguments
+/// * `cpu_fraction` - Fraction of available cores to use (e.g., 0.9 for 90%).
+///   Values are clamped to the range [0.1, 1.0].
+pub fn configure_rayon_thread_pool(cpu_fraction: f64) {
+    // Clamp cpu_fraction to valid range
+    let cpu_fraction = cpu_fraction.clamp(0.1, 1.0);
+
+    let available_cores = std::thread::available_parallelism()
+        .map(|n| n.get())
+        .unwrap_or(4);
+
+    let target_threads = ((available_cores as f64) * cpu_fraction).floor() as usize;
+    let target_threads = target_threads.max(1); // At least 1 thread
+
+    // Only configure if we haven't already (this can only be called once)
+    match rayon::ThreadPoolBuilder::new()
+        .num_threads(target_threads)
+        .build_global()
+    {
+        Ok(()) => {
+            // Successfully configured (silent to avoid cluttering output)
+        }
+        Err(_) => {
+            // Thread pool already configured
+        }
+    }
+}

src/ground.rs

@@ -23,12 +23,22 @@ impl Ground {
     }
 
     pub fn new_enabled(bbox: &LLBBox, scale: f64, ground_level: i32) -> Self {
-        let elevation_data = fetch_elevation_data(bbox, scale, ground_level)
-            .expect("Failed to fetch elevation data");
-        Self {
-            elevation_enabled: true,
-            ground_level,
-            elevation_data: Some(elevation_data),
+        match fetch_elevation_data(bbox, scale, ground_level) {
+            Ok(elevation_data) => Self {
+                elevation_enabled: true,
+                ground_level,
+                elevation_data: Some(elevation_data),
+            },
+            Err(e) => {
+                eprintln!("Failed to fetch elevation data: {}", e);
+                emit_gui_progress_update(15.0, "Elevation unavailable, using flat ground");
+                // Graceful fallback: disable elevation and keep provided ground_level
+                Self {
+                    elevation_enabled: false,
+                    ground_level,
+                    elevation_data: None,
+                }
+            }
         }
     }
 

src/gui.rs

@@ -1,21 +1,25 @@
 use crate::args::Args;
-use crate::coordinate_system::cartesian::XZPoint;
+use crate::coordinate_system::cartesian::{XZBBox, XZPoint};
 use crate::coordinate_system::geographic::{LLBBox, LLPoint};
-use crate::data_processing;
+use crate::coordinate_system::transformation::CoordTransformer;
+use crate::data_processing::{self, GenerationOptions};
 use crate::ground::{self, Ground};
 use crate::map_transformation;
 use crate::osm_parser;
-use crate::progress;
+use crate::progress::{self, emit_gui_progress_update};
 use crate::retrieve_data;
+use crate::telemetry::{self, send_log, LogLevel};
 use crate::version_check;
+use crate::world_editor::WorldFormat;
+use colored::Colorize;
 use fastnbt::Value;
 use flate2::read::GzDecoder;
 use fs2::FileExt;
-use log::{error, LevelFilter};
+use log::LevelFilter;
 use rfd::FileDialog;
 use std::io::Read;
 use std::path::{Path, PathBuf};
-use std::{env, fs, io::Write, panic};
+use std::{env, fs, io::Write};
 use tauri_plugin_log::{Builder as LogBuilder, Target, TargetKind};
 
 /// Manages the session.lock file for a Minecraft world directory
@@ -58,16 +62,26 @@ impl Drop for SessionLock {
     }
 }
 
+/// Gets the area name for a given bounding box using the center point
+fn get_area_name_for_bedrock(bbox: &LLBBox) -> String {
+    let center_lat = (bbox.min().lat() + bbox.max().lat()) / 2.0;
+    let center_lon = (bbox.min().lng() + bbox.max().lng()) / 2.0;
+
+    match retrieve_data::fetch_area_name(center_lat, center_lon) {
+        Ok(Some(name)) => name,
+        _ => "Unknown Location".to_string(),
+    }
+}
+
 pub fn run_gui() {
+    // Configure thread pool with 90% CPU cap to keep system responsive
+    crate::floodfill_cache::configure_rayon_thread_pool(0.9);
+
     // Launch the UI
     println!("Launching UI...");
 
-    // Set a custom panic hook to log panic information
-    panic::set_hook(Box::new(|panic_info| {
-        let message = format!("Application panicked: {panic_info:?}");
-        error!("{message}");
-        std::process::exit(1);
-    }));
+    // Install panic hook for crash reporting
+    telemetry::install_panic_hook();
 
     // Workaround WebKit2GTK issue with NVIDIA drivers and graphics issues
     // Source: https://github.com/tauri-apps/tauri/issues/10702
@@ -102,7 +116,9 @@ pub fn run_gui() {
             gui_select_world,
             gui_start_generation,
             gui_get_version,
-            gui_check_for_updates
+            gui_check_for_updates,
+            gui_get_world_map_data,
+            gui_show_in_folder
         ])
         .setup(|app| {
             let app_handle = app.handle();
@@ -142,16 +158,20 @@ fn gui_select_world(generate_new: bool) -> Result<String, i32> {
 
     if generate_new {
         // Handle new world generation
-        if let Some(default_path) = &default_dir {
+        // Try Minecraft saves directory first, fall back to current directory
+        let target_path = if let Some(default_path) = &default_dir {
             if default_path.exists() {
-                // Call create_new_world and return the result
-                create_new_world(default_path).map_err(|_| 1) // Error code 1: Minecraft directory not found
+                default_path.clone()
             } else {
-                Err(1) // Error code 1: Minecraft directory not found
+                // Minecraft directory doesn't exist, use current directory
+                env::current_dir().unwrap_or_else(|_| PathBuf::from("."))
             }
         } else {
-            Err(1) // Error code 1: Minecraft directory not found
-        }
+            // No default directory configured, use current directory
+            env::current_dir().unwrap_or_else(|_| PathBuf::from("."))
+        };
+
+        create_new_world(&target_path).map_err(|_| 3) // Error code 3: Failed to create new world
     } else {
         // Handle existing world selection
         // Open the directory picker dialog
@@ -226,13 +246,13 @@ fn create_new_world(base_path: &Path) -> Result<String, String> {
         .map_err(|e| format!("Failed to create world directory: {e}"))?;
 
     // Copy the region template file
-    const REGION_TEMPLATE: &[u8] = include_bytes!("../mcassets/region.template");
+    const REGION_TEMPLATE: &[u8] = include_bytes!("../assets/minecraft/region.template");
     let region_path = new_world_path.join("region").join("r.0.0.mca");
     fs::write(&region_path, REGION_TEMPLATE)
         .map_err(|e| format!("Failed to create region file: {e}"))?;
 
     // Add the level.dat file
-    const LEVEL_TEMPLATE: &[u8] = include_bytes!("../mcassets/level.dat");
+    const LEVEL_TEMPLATE: &[u8] = include_bytes!("../assets/minecraft/level.dat");
 
     // Decompress the gzipped level.template
     let mut decoder = GzDecoder::new(LEVEL_TEMPLATE);
@@ -299,7 +319,7 @@ fn create_new_world(base_path: &Path) -> Result<String, String> {
         .map_err(|e| format!("Failed to create level.dat file: {e}"))?;
 
     // Add the icon.png file
-    const ICON_TEMPLATE: &[u8] = include_bytes!("../mcassets/icon.png");
+    const ICON_TEMPLATE: &[u8] = include_bytes!("../assets/minecraft/icon.png");
     fs::write(new_world_path.join("icon.png"), ICON_TEMPLATE)
         .map_err(|e| format!("Failed to create icon.png file: {e}"))?;
 
@@ -307,52 +327,45 @@ fn create_new_world(base_path: &Path) -> Result<String, String> {
 }
 
 /// Adds localized area name to the world name in level.dat
-fn add_localized_world_name(world_path_str: &str, bbox: &LLBBox) -> String {
-    let world_path = PathBuf::from(world_path_str);
-
+fn add_localized_world_name(world_path: PathBuf, bbox: &LLBBox) -> PathBuf {
     // Only proceed if the path exists
     if !world_path.exists() {
-        return world_path_str.to_string();
+        return world_path;
     }
 
     // Check the level.dat file first to get the current name
     let level_path = world_path.join("level.dat");
 
     if !level_path.exists() {
-        return world_path_str.to_string();
+        return world_path;
     }
 
     // Try to read the current world name from level.dat
-    let current_name = match std::fs::read(&level_path) {
-        Ok(level_data) => {
-            let mut decoder = GzDecoder::new(level_data.as_slice());
-            let mut decompressed_data = Vec::new();
-            if decoder.read_to_end(&mut decompressed_data).is_ok() {
-                if let Ok(Value::Compound(ref root)) =
-                    fastnbt::from_bytes::<Value>(&decompressed_data)
-                {
-                    if let Some(Value::Compound(ref data)) = root.get("Data") {
-                        if let Some(Value::String(name)) = data.get("LevelName") {
-                            name.clone()
-                        } else {
-                            return world_path_str.to_string();
-                        }
-                    } else {
-                        return world_path_str.to_string();
-                    }
-                } else {
-                    return world_path_str.to_string();
-                }
-            } else {
-                return world_path_str.to_string();
-            }
-        }
-        Err(_) => return world_path_str.to_string(),
+    let Ok(level_data) = std::fs::read(&level_path) else {
+        return world_path;
+    };
+
+    let mut decoder = GzDecoder::new(level_data.as_slice());
+    let mut decompressed_data = Vec::new();
+    if decoder.read_to_end(&mut decompressed_data).is_err() {
+        return world_path;
+    }
+
+    let Ok(Value::Compound(ref root)) = fastnbt::from_bytes::<Value>(&decompressed_data) else {
+        return world_path;
+    };
+
+    let Some(Value::Compound(ref data)) = root.get("Data") else {
+        return world_path;
+    };
+
+    let Some(Value::String(current_name)) = data.get("LevelName") else {
+        return world_path;
     };
 
     // Only modify if it's an Arnis world and doesn't already have an area name
     if !current_name.starts_with("Arnis World ") || current_name.contains(": ") {
-        return world_path_str.to_string();
+        return world_path;
     }
 
     // Calculate center coordinates of bbox
@@ -362,7 +375,7 @@ fn add_localized_world_name(world_path_str: &str, bbox: &LLBBox) -> String {
     // Try to fetch the area name
     let area_name = match retrieve_data::fetch_area_name(center_lat, center_lon) {
         Ok(Some(name)) => name,
-        _ => return world_path_str.to_string(), // Keep original name if no area name found
+        _ => return world_path, // Keep original name if no area name found
     };
 
     // Create new name with localized area name, ensuring total length doesn't exceed 30 characters
@@ -378,7 +391,7 @@ fn add_localized_world_name(world_path_str: &str, bbox: &LLBBox) -> String {
                 .collect::<String>()
         } else if max_area_name_len == 0 {
             // If base name is already too long, don't add area name
-            return world_path_str.to_string();
+            return world_path;
         } else {
             area_name
         };
@@ -406,6 +419,10 @@ fn add_localized_world_name(world_path_str: &str, bbox: &LLBBox) -> String {
                                 if let Ok(compressed_data) = encoder.finish() {
                                     if let Err(e) = std::fs::write(&level_path, compressed_data) {
                                         eprintln!("Failed to update level.dat with area name: {e}");
+                                        send_log(
+                                            LogLevel::Warning,
+                                            "Failed to update level.dat with area name",
+                                        );
                                     }
                                 }
                             }
@@ -417,39 +434,23 @@ fn add_localized_world_name(world_path_str: &str, bbox: &LLBBox) -> String {
     }
 
     // Return the original path since we didn't change the directory name
-    world_path_str.to_string()
+    world_path
 }
 
-// Function to update player position in level.dat based on spawn point coordinates
-fn update_player_position(
+/// Calculates the default spawn point at X=1, Z=1 relative to the world origin.
+/// This is used when no spawn point is explicitly selected by the user.
+fn calculate_default_spawn(xzbbox: &XZBBox) -> (i32, i32) {
+    (xzbbox.min_x() + 1, xzbbox.min_z() + 1)
+}
+
+/// Sets the player spawn point in level.dat using Minecraft XZ coordinates.
+/// The Y coordinate is set to a temporary value (150) and will be updated
+/// after terrain generation by `update_player_spawn_y_after_generation`.
+fn set_player_spawn_in_level_dat(
     world_path: &str,
-    spawn_point: Option<(f64, f64)>,
-    bbox_text: String,
-    scale: f64,
+    spawn_x: i32,
+    spawn_z: i32,
 ) -> Result<(), String> {
-    use crate::coordinate_system::transformation::CoordTransformer;
-
-    let Some((lat, lng)) = spawn_point else {
-        return Ok(()); // No spawn point selected, exit early
-    };
-
-    // Parse geometrical point and bounding box
-    let llpoint =
-        LLPoint::new(lat, lng).map_err(|e| format!("Failed to parse spawn point:\n{e}"))?;
-    let llbbox = LLBBox::from_str(&bbox_text)
-        .map_err(|e| format!("Failed to parse bounding box for spawn point:\n{e}"))?;
-
-    // Check if spawn point is within the bbox
-    if !llbbox.contains(&llpoint) {
-        return Err("Spawn point is outside the selected area".to_string());
-    }
-
-    // Convert lat/lng to Minecraft coordinates
-    let (transformer, _) = CoordTransformer::llbbox_to_xzbbox(&llbbox, scale)
-        .map_err(|e| format!("Failed to build transformation on coordinate systems:\n{e}"))?;
-
-    let xzpoint = transformer.transform_point(llpoint);
-
     // Default y spawn position since terrain elevation cannot be determined yet
     let y = 150.0;
 
@@ -481,21 +482,24 @@ fn update_player_position(
     if let Value::Compound(ref mut root) = nbt_data {
         if let Some(Value::Compound(ref mut data)) = root.get_mut("Data") {
             // Set world spawn point
-            data.insert("SpawnX".to_string(), Value::Int(xzpoint.x));
+            data.insert("SpawnX".to_string(), Value::Int(spawn_x));
             data.insert("SpawnY".to_string(), Value::Int(y as i32));
-            data.insert("SpawnZ".to_string(), Value::Int(xzpoint.z));
+            data.insert("SpawnZ".to_string(), Value::Int(spawn_z));
 
-            // Update player position
+            // Update player position if Player compound exists
             if let Some(Value::Compound(ref mut player)) = data.get_mut("Player") {
                 if let Some(Value::List(ref mut pos)) = player.get_mut("Pos") {
-                    if let Value::Double(ref mut pos_x) = pos.get_mut(0).unwrap() {
-                        *pos_x = xzpoint.x as f64;
-                    }
-                    if let Value::Double(ref mut pos_y) = pos.get_mut(1).unwrap() {
-                        *pos_y = y;
-                    }
-                    if let Value::Double(ref mut pos_z) = pos.get_mut(2).unwrap() {
-                        *pos_z = xzpoint.z as f64;
+                    // Safely update position values with bounds checking
+                    if pos.len() >= 3 {
+                        if let Some(Value::Double(ref mut pos_x)) = pos.get_mut(0) {
+                            *pos_x = spawn_x as f64;
+                        }
+                        if let Some(Value::Double(ref mut pos_y)) = pos.get_mut(1) {
+                            *pos_y = y;
+                        }
+                        if let Some(Value::Double(ref mut pos_z)) = pos.get_mut(2) {
+                            *pos_z = spawn_z as f64;
+                        }
                     }
                 }
             }
@@ -527,19 +531,15 @@ fn update_player_position(
 }
 
 // Function to update player spawn Y coordinate based on terrain height after generation
+// This updates the spawn Y coordinate to be at terrain height + 3 blocks
 pub fn update_player_spawn_y_after_generation(
-    world_path: &str,
-    spawn_point: Option<(f64, f64)>,
+    world_path: &Path,
     bbox_text: String,
     scale: f64,
     ground: &Ground,
 ) -> Result<(), String> {
     use crate::coordinate_system::transformation::CoordTransformer;
 
-    let Some((_lat, _lng)) = spawn_point else {
-        return Ok(()); // No spawn point selected, exit early
-    };
-
     // Read the current level.dat file to get existing spawn coordinates
     let level_path = PathBuf::from(world_path).join("level.dat");
     if !level_path.exists() {
@@ -608,7 +608,7 @@ pub fn update_player_spawn_y_after_generation(
         let relative_z = existing_spawn_z - xzbbox.min_z();
         let terrain_point = XZPoint::new(relative_x, relative_z);
 
-        ground.level(terrain_point) + 2
+        ground.level(terrain_point) + 3 // Add 3 blocks above terrain for safety
     } else {
         -61 // Default Y if no terrain
     };
@@ -622,8 +622,8 @@ pub fn update_player_spawn_y_after_generation(
             // Update player position - only Y coordinate
             if let Some(Value::Compound(ref mut player)) = data.get_mut("Player") {
                 if let Some(Value::List(ref mut pos)) = player.get_mut("Pos") {
-                    // Keep existing X and Z, only update Y
-                    if let Value::Double(ref mut pos_y) = pos.get_mut(1).unwrap() {
+                    // Safely update Y position with bounds checking
+                    if let Some(Value::Double(ref mut pos_y)) = pos.get_mut(1) {
                         *pos_y = spawn_y as f64;
                     }
                 }
@@ -668,6 +668,114 @@ fn gui_check_for_updates() -> Result<bool, String> {
     }
 }
 
+/// Returns the world map image data as base64 and geo bounds for overlay display.
+/// Returns None if the map image or metadata doesn't exist.
+#[tauri::command]
+fn gui_get_world_map_data(world_path: String) -> Result<Option<WorldMapData>, String> {
+    let world_dir = PathBuf::from(&world_path);
+    let map_path = world_dir.join("arnis_world_map.png");
+    let metadata_path = world_dir.join("metadata.json");
+
+    // Check if both files exist
+    if !map_path.exists() || !metadata_path.exists() {
+        return Ok(None);
+    }
+
+    // Read and encode the map image as base64
+    let image_data = fs::read(&map_path).map_err(|e| format!("Failed to read map image: {e}"))?;
+    let base64_image =
+        base64::Engine::encode(&base64::engine::general_purpose::STANDARD, &image_data);
+
+    // Read metadata
+    let metadata_content =
+        fs::read_to_string(&metadata_path).map_err(|e| format!("Failed to read metadata: {e}"))?;
+    let metadata: serde_json::Value = serde_json::from_str(&metadata_content)
+        .map_err(|e| format!("Failed to parse metadata: {e}"))?;
+
+    // Extract geo bounds (metadata uses camelCase from serde)
+    let min_lat = metadata["minGeoLat"]
+        .as_f64()
+        .ok_or("Missing minGeoLat in metadata")?;
+    let max_lat = metadata["maxGeoLat"]
+        .as_f64()
+        .ok_or("Missing maxGeoLat in metadata")?;
+    let min_lon = metadata["minGeoLon"]
+        .as_f64()
+        .ok_or("Missing minGeoLon in metadata")?;
+    let max_lon = metadata["maxGeoLon"]
+        .as_f64()
+        .ok_or("Missing maxGeoLon in metadata")?;
+
+    Ok(Some(WorldMapData {
+        image_base64: format!("data:image/png;base64,{}", base64_image),
+        min_lat,
+        max_lat,
+        min_lon,
+        max_lon,
+    }))
+}
+
+/// Data structure for world map overlay
+#[derive(serde::Serialize)]
+struct WorldMapData {
+    image_base64: String,
+    min_lat: f64,
+    max_lat: f64,
+    min_lon: f64,
+    max_lon: f64,
+}
+
+/// Opens the file with default application (Windows) or shows in file explorer (macOS/Linux)
+#[tauri::command]
+fn gui_show_in_folder(path: String) -> Result<(), String> {
+    #[cfg(target_os = "windows")]
+    {
+        // On Windows, try to open with default application (Minecraft Bedrock)
+        // If that fails, show in Explorer
+        if std::process::Command::new("cmd")
+            .args(["/C", "start", "", &path])
+            .spawn()
+            .is_err()
+        {
+            std::process::Command::new("explorer")
+                .args(["/select,", &path])
+                .spawn()
+                .map_err(|e| format!("Failed to open explorer: {}", e))?;
+        }
+    }
+
+    #[cfg(target_os = "macos")]
+    {
+        // On macOS, just reveal in Finder
+        std::process::Command::new("open")
+            .args(["-R", &path])
+            .spawn()
+            .map_err(|e| format!("Failed to open Finder: {}", e))?;
+    }
+
+    #[cfg(target_os = "linux")]
+    {
+        // On Linux, just show in file manager
+        let path_parent = std::path::Path::new(&path)
+            .parent()
+            .map(|p| p.to_string_lossy().to_string())
+            .unwrap_or_else(|| path.clone());
+
+        // Try nautilus with select first, then fall back to xdg-open on parent
+        if std::process::Command::new("nautilus")
+            .args(["--select", &path])
+            .spawn()
+            .is_err()
+        {
+            let _ = std::process::Command::new("xdg-open")
+                .arg(&path_parent)
+                .spawn();
+        }
+    }
+
+    Ok(())
+}
+
 #[tauri::command]
 #[allow(clippy::too_many_arguments)]
 #[allow(unused_variables)]
@@ -676,59 +784,118 @@ fn gui_start_generation(
     selected_world: String,
     world_scale: f64,
     ground_level: i32,
-    floodfill_timeout: u64,
     terrain_enabled: bool,
+    skip_osm_objects: bool,
     interior_enabled: bool,
     roof_enabled: bool,
     fillground_enabled: bool,
     is_new_world: bool,
     spawn_point: Option<(f64, f64)>,
+    telemetry_consent: bool,
+    world_format: String,
 ) -> Result<(), String> {
     use progress::emit_gui_error;
     use LLBBox;
 
-    // If spawn point was chosen and the world is new, check and set the spawn point
-    if is_new_world && spawn_point.is_some() {
-        // Verify the spawn point is within bounds
-        if let Some(coords) = spawn_point {
-            let llbbox = match LLBBox::from_str(&bbox_text) {
-                Ok(bbox) => bbox,
-                Err(e) => {
-                    let error_msg = format!("Failed to parse bounding box: {e}");
-                    eprintln!("{error_msg}");
-                    emit_gui_error(&error_msg);
-                    return Err(error_msg);
-                }
-            };
+    // Store telemetry consent for crash reporting
+    telemetry::set_telemetry_consent(telemetry_consent);
 
+    // Send generation click telemetry
+    telemetry::send_generation_click();
+
+    // For new Java worlds, set the spawn point in level.dat
+    // Only update player position for Java worlds - Bedrock worlds don't have a pre-existing
+    // level.dat to modify (the spawn point will be set when the .mcworld is created)
+    if is_new_world && world_format != "bedrock" {
+        let llbbox = match LLBBox::from_str(&bbox_text) {
+            Ok(bbox) => bbox,
+            Err(e) => {
+                let error_msg = format!("Failed to parse bounding box: {e}");
+                eprintln!("{error_msg}");
+                emit_gui_error(&error_msg);
+                return Err(error_msg);
+            }
+        };
+
+        let (transformer, xzbbox) = match CoordTransformer::llbbox_to_xzbbox(&llbbox, world_scale) {
+            Ok(result) => result,
+            Err(e) => {
+                let error_msg = format!("Failed to create coordinate transformer: {e}");
+                eprintln!("{error_msg}");
+                emit_gui_error(&error_msg);
+                return Err(error_msg);
+            }
+        };
+
+        let (spawn_x, spawn_z) = if let Some(coords) = spawn_point {
+            // User selected a spawn point - verify it's within bounds and convert to XZ
             let llpoint = LLPoint::new(coords.0, coords.1)
                 .map_err(|e| format!("Failed to parse spawn point: {e}"))?;
 
             if llbbox.contains(&llpoint) {
-                // Spawn point is valid, update the player position
-                update_player_position(
-                    &selected_world,
-                    spawn_point,
-                    bbox_text.clone(),
-                    world_scale,
-                )
-                .map_err(|e| format!("Failed to set spawn point: {e}"))?;
+                let xzpoint = transformer.transform_point(llpoint);
+                (xzpoint.x, xzpoint.z)
+            } else {
+                // Spawn point outside bounds, use default
+                calculate_default_spawn(&xzbbox)
             }
-        }
+        } else {
+            // No user-selected spawn point - use default at X=1, Z=1 relative to world origin
+            calculate_default_spawn(&xzbbox)
+        };
+
+        set_player_spawn_in_level_dat(&selected_world, spawn_x, spawn_z)
+            .map_err(|e| format!("Failed to set spawn point: {e}"))?;
     }
 
     tauri::async_runtime::spawn(async move {
         if let Err(e) = tokio::task::spawn_blocking(move || {
-            // Acquire session lock for the world directory before starting generation
             let world_path = PathBuf::from(&selected_world);
-            let _session_lock = match SessionLock::acquire(&world_path) {
-                Ok(lock) => lock,
-                Err(e) => {
-                    let error_msg = format!("Failed to acquire session lock: {e}");
+
+            // Determine world format from UI selection first (needed for session lock decision)
+            let world_format = if world_format == "bedrock" {
+                WorldFormat::BedrockMcWorld
+            } else {
+                WorldFormat::JavaAnvil
+            };
+
+            // Check available disk space before starting generation (minimum 3GB required)
+            const MIN_DISK_SPACE_BYTES: u64 = 3 * 1024 * 1024 * 1024; // 3 GB
+            let check_path = if world_format == WorldFormat::JavaAnvil {
+                world_path.clone()
+            } else {
+                // For Bedrock, check current directory where .mcworld will be created
+                std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."))
+            };
+            match fs2::available_space(&check_path) {
+                Ok(available) if available < MIN_DISK_SPACE_BYTES => {
+                    let error_msg = "Not enough disk space available.".to_string();
                     eprintln!("{error_msg}");
                     emit_gui_error(&error_msg);
                     return Err(error_msg);
                 }
+                Err(e) => {
+                    // Log warning but don't block generation if we can't check space
+                    eprintln!("Warning: Could not check disk space: {e}");
+                }
+                _ => {} // Sufficient space available
+            }
+
+            // Acquire session lock for Java worlds only
+            // Session lock prevents Minecraft from having the world open during generation
+            // Bedrock worlds are generated as .mcworld files and don't need this lock
+            let _session_lock: Option<SessionLock> = if world_format == WorldFormat::JavaAnvil {
+                match SessionLock::acquire(&world_path) {
+                    Ok(lock) => Some(lock),
+                    Err(e) => {
+                        let error_msg = format!("Failed to acquire session lock: {e}");
+                        eprintln!("{error_msg}");
+                        emit_gui_error(&error_msg);
+                        return Err(error_msg);
+                    }
+                }
+            } else {
+                None
             };
 
             // Parse the bounding box from the text with proper error handling
@@ -742,19 +909,72 @@ fn gui_start_generation(
                 }
             };
 
-            // Add localized name to the world if user generated a new world
-            let updated_world_path = if is_new_world {
-                add_localized_world_name(&selected_world, &bbox)
-            } else {
-                selected_world.clone()
+            // Determine output path and level name based on format
+            let (generation_path, level_name) = match world_format {
+                WorldFormat::JavaAnvil => {
+                    // Java: use the selected world path, add localized name if new
+                    let updated_path = if is_new_world {
+                        add_localized_world_name(world_path.clone(), &bbox)
+                    } else {
+                        world_path.clone()
+                    };
+                    (updated_path, None)
+                }
+                WorldFormat::BedrockMcWorld => {
+                    // Bedrock: generate .mcworld in current directory with location-based name
+                    let area_name = get_area_name_for_bedrock(&bbox);
+                    let filename = format!("Arnis {}.mcworld", area_name);
+                    let lvl_name = format!("Arnis World: {}", area_name);
+                    let output_path = std::env::current_dir()
+                        .unwrap_or_else(|_| PathBuf::from("."))
+                        .join(filename);
+                    (output_path, Some(lvl_name))
+                }
             };
 
-            // Create an Args instance with the chosen bounding box and world directory path
+            // Calculate MC spawn coordinates from lat/lng if spawn point was provided
+            // Otherwise, default to X=1, Z=1 (relative to xzbbox min coordinates)
+            let mc_spawn_point: Option<(i32, i32)> = if let Some((lat, lng)) = spawn_point {
+                if let Ok(llpoint) = LLPoint::new(lat, lng) {
+                    if let Ok((transformer, _)) =
+                        CoordTransformer::llbbox_to_xzbbox(&bbox, world_scale)
+                    {
+                        let xzpoint = transformer.transform_point(llpoint);
+                        Some((xzpoint.x, xzpoint.z))
+                    } else {
+                        None
+                    }
+                } else {
+                    None
+                }
+            } else {
+                // Default spawn point: X=1, Z=1 relative to world origin
+                if let Ok((_, xzbbox)) = CoordTransformer::llbbox_to_xzbbox(&bbox, world_scale) {
+                    Some(calculate_default_spawn(&xzbbox))
+                } else {
+                    None
+                }
+            };
+
+            // Create generation options
+            let generation_options = GenerationOptions {
+                path: generation_path.clone(),
+                format: world_format,
+                level_name,
+                spawn_point: mc_spawn_point,
+            };
+
+            // Create an Args instance with the chosen bounding box
+            // Note: path is used for Java-specific features like spawn point update
             let args: Args = Args {
                 bbox,
                 file: None,
                 save_json_file: None,
-                path: updated_world_path,
+                path: if world_format == WorldFormat::JavaAnvil {
+                    generation_path
+                } else {
+                    world_path
+                },
                 downloader: "requests".to_string(),
                 scale: world_scale,
                 ground_level,
@@ -763,11 +983,47 @@ fn gui_start_generation(
                 roof: roof_enabled,
                 fillground: fillground_enabled,
                 debug: false,
-                timeout: Some(std::time::Duration::from_secs(floodfill_timeout)),
-                spawn_point,
+                timeout: Some(std::time::Duration::from_secs(40)),
             };
 
-            // Run data fetch and world generation
+            // If skip_osm_objects is true (terrain-only mode), skip fetching and processing OSM data
+            if skip_osm_objects {
+                // Generate ground data (terrain) for terrain-only mode
+                let ground = ground::generate_ground_data(&args);
+
+                // Create empty parsed_elements and xzbbox for terrain-only mode
+                let parsed_elements = Vec::new();
+                let (_coord_transformer, xzbbox) =
+                    CoordTransformer::llbbox_to_xzbbox(&args.bbox, args.scale)
+                        .map_err(|e| format!("Failed to create coordinate transformer: {}", e))?;
+
+                let _ = data_processing::generate_world_with_options(
+                    parsed_elements,
+                    xzbbox.clone(),
+                    args.bbox,
+                    ground,
+                    &args,
+                    generation_options.clone(),
+                );
+                // Explicitly release session lock before showing Done message
+                // so Minecraft can open the world immediately
+                drop(_session_lock);
+                emit_gui_progress_update(100.0, "Done! World generation completed.");
+                println!("{}", "Done! World generation completed.".green().bold());
+
+                // Start map preview generation silently in background (Java only)
+                if world_format == WorldFormat::JavaAnvil {
+                    let preview_info = data_processing::MapPreviewInfo::new(
+                        generation_options.path.clone(),
+                        &xzbbox,
+                    );
+                    data_processing::start_map_preview_generation(preview_info);
+                }
+
+                return Ok(());
+            }
+
+            // Run data fetch and world generation (standard mode: objects + terrain, or objects only)
             match retrieve_data::fetch_data_from_overpass(args.bbox, args.debug, "requests", None) {
                 Ok(raw_data) => {
                     let (mut parsed_elements, mut xzbbox) =
@@ -794,15 +1050,35 @@ fn gui_start_generation(
                         &mut ground,
                     );
 
-                    let _ = data_processing::generate_world(parsed_elements, xzbbox, ground, &args);
-                    // Session lock will be automatically released when _session_lock goes out of scope
+                    let _ = data_processing::generate_world_with_options(
+                        parsed_elements,
+                        xzbbox.clone(),
+                        args.bbox,
+                        ground,
+                        &args,
+                        generation_options.clone(),
+                    );
+                    // Explicitly release session lock before showing Done message
+                    // so Minecraft can open the world immediately
+                    drop(_session_lock);
+                    emit_gui_progress_update(100.0, "Done! World generation completed.");
+                    println!("{}", "Done! World generation completed.".green().bold());
+
+                    // Start map preview generation silently in background (Java only)
+                    if world_format == WorldFormat::JavaAnvil {
+                        let preview_info = data_processing::MapPreviewInfo::new(
+                            generation_options.path.clone(),
+                            &xzbbox,
+                        );
+                        data_processing::start_map_preview_generation(preview_info);
+                    }
+
                     Ok(())
                 }
                 Err(e) => {
-                    let error_msg = format!("Failed to fetch data: {e}");
-                    emit_gui_error(&error_msg);
+                    emit_gui_error(&e.to_string());
                     // Session lock will be automatically released when _session_lock goes out of scope
-                    Err(error_msg)
+                    Err(e.to_string())
                 }
             }
         })

src/gui/css/bbox.css

@@ -8,13 +8,9 @@ body,
   font-family: "Courier New", Courier, monospace;
 }
 
+/* Hide the BBOX coordinates display at bottom of map */
 #info-box {
-  position: absolute;
-  width: 100%;
-  height: auto;
-  bottom: 0;
-  border: 0 0 7px 0;
-  z-index: 10000;
+  display: none;
 }
 
 #coord-format {
@@ -344,4 +340,39 @@ body,
   filter: blur(1px) sepia(1) invert(1);
   transition: all 1s ease;
 
+}
+
+/* World Preview Button in Edit Toolbar */
+.leaflet-draw-toolbar .leaflet-draw-edit-preview {
+  background-position: -31px -2px;
+}
+
+.leaflet-draw-toolbar .leaflet-draw-edit-preview.disabled,
+.leaflet-draw-toolbar .leaflet-draw-edit-preview.editing-mode {
+  opacity: 0.4;
+  cursor: not-allowed;
+  pointer-events: none;
+}
+
+.leaflet-draw-toolbar .leaflet-draw-edit-preview.active {
+  background-color: #a0d0ff;
+}
+
+.world-preview-slider-container {
+  padding: 6px 8px !important;
+  background: white !important;
+  background-clip: padding-box;
+}
+
+.world-preview-slider-container a {
+  display: none !important;
+}
+
+.world-preview-slider {
+  width: 80px;
+  height: 8px;
+  cursor: pointer;
+  accent-color: #3887BE;
+  display: block;
+  margin: 0;
 }

src/gui/css/maps/leaflet.draw.css

@@ -158,12 +158,13 @@
 	background-position: -182px -2px;
 }
 
+/* Disabled states reuse same sprites; opacity indicates disabled */
 .leaflet-draw-toolbar .leaflet-draw-edit-edit.leaflet-disabled {
-	background-position: -212px -2px;
+	background-position: -152px -2px;
 }
 
 .leaflet-draw-toolbar .leaflet-draw-edit-remove.leaflet-disabled {
-	background-position: -242px -2px;
+	background-position: -182px -2px;
 }
 
 /* ================================================================== */

src/gui/css/styles.css

@@ -32,9 +32,12 @@ p {
 
 .logo {
   height: 6em;
-  padding: 1.5em;
+  padding-top: 0.4em;
+  padding-bottom: 0.5em;
   will-change: filter;
   transition: 0.75s;
+  max-width: 950px;
+  max-height: 600px;
 }
 
 .logo.arnis:hover {
@@ -59,10 +62,11 @@ a:hover {
 
 .flex-container {
   display: flex;
-  gap: 20px;
+  gap: 15px;
   justify-content: center;
   align-items: stretch;
   margin-top: 5px;
+  min-height: 70vh;
 }
 
 .section {
@@ -74,26 +78,60 @@ a:hover {
 
 .map-box,
 .controls-box {
-  width: 45%;
+  display: flex;
+  flex-direction: column;
+}
+
+.map-box {
+  width: 63%;
+  min-height: 420px;
+  padding: 0;
+  overflow: hidden;
   background: #575757;
-  padding: 20px;
   border-radius: 8px;
   box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
 }
 
+.controls-box {
+  width: 32%;
+  background: transparent;
+  padding: 0;
+  border-radius: 0;
+  box-shadow: none;
+}
+
 .controls-content {
   display: flex;
   flex-direction: column;
   height: 100%;
+  justify-content: space-between;
 }
 
 .controls-box .progress-section {
-  margin-top: auto;
+  margin-top: 0;
+}
+
+.controls-top {
+  display: flex;
+  flex-direction: column;
+}
+
+.bbox-info-text {
+  font-size: 0.9em;
+  color: #ffffff;
+  display: block;
+  font-weight: bold;
+  min-height: 2.5em;
+  line-height: 1.25em;
+  margin-bottom: 5px;
 }
 
 .map-container {
-  border: 2px solid #e0e0e0;
+  border: none;
   border-radius: 8px;
+  flex-grow: 1;
+  width: 100%;
+  height: 100%;
 }
 
 .section h2 {
@@ -133,18 +171,26 @@ button:hover {
   margin-top: auto;
 }
 
-.progress-section h2 {
-  margin-bottom: 8px;
-  text-align: center;
+.progress-row {
+  display: flex;
+  align-items: center;
+  gap: 10px;
 }
 
 .progress-bar-container {
-  width: 100%;
+  flex: 1;
+  max-width: 80%;
   height: 20px;
   background-color: #e0e0e0;
   border-radius: 10px;
   overflow: hidden;
-  margin-top: 8px;
+}
+
+#progress-detail {
+  min-width: 40px;
+  text-align: right;
+  font-size: 0.9em;
+  color: #fff;
 }
 
 .progress-bar {
@@ -154,15 +200,6 @@ button:hover {
   transition: width 0.4s;
 }
 
-/* Left and right alignment for "Saving world..." text */
-.progress-status {
-  display: flex;
-  justify-content: space-between;
-  font-size: 0.9em;
-  margin-top: 8px;
-  color: #fff;
-}
-
 .footer {
   margin-top: 20px;
   text-align: center;
@@ -181,7 +218,7 @@ button:hover {
 @media (prefers-color-scheme: dark) {
   :root {
     color: #f6f6f6;
-    background-color: #2f2f2f;
+    background-color: #333333;
   }
 
   p {
@@ -213,10 +250,73 @@ button:hover {
   width: 100%;
 }
 
+/* World Selection Container */
+.world-selection-container {
+  width: 100%;
+}
+
+.choose-world-btn {
+  padding: 10px;
+  line-height: 1.2;
+  width: 100%;
+  border-radius: 8px 8px 0 0 !important;
+  margin-bottom: 0 !important;
+  margin-top: 0 !important;
+  box-shadow: none !important;
+}
+
+/* World Format Toggle */
+.format-toggle-container {
+  display: flex;
+  width: 100%;
+  gap: 0;
+  margin-top: 0;
+}
+
+.format-toggle-btn {
+  flex: 1;
+  padding: 10px;
+  font-size: 1em;
+  font-weight: 500;
+  border: 1px solid transparent;
+  cursor: pointer;
+  transition: all 0.25s ease;
+  margin-top: 0;
+  border-radius: 0;
+}
+
+.format-toggle-btn:first-child {
+  border-radius: 0 0 0 8px;
+}
+
+.format-toggle-btn:last-child {
+  border-radius: 0 0 8px 0;
+}
+
+.format-toggle-btn:not(.format-active) {
+  background-color: #3a3a3a;
+  color: #b0b0b0;
+}
+
+.format-toggle-btn:not(.format-active):hover {
+  background-color: #4a4a4a;
+  color: #ffffff;
+}
+
+.format-toggle-btn.format-active {
+  background-color: var(--primary-accent);
+  color: #0f0f0f;
+  font-weight: 600;
+}
+
+.format-toggle-btn.format-active:hover {
+  background-color: var(--primary-accent-dark);
+}
+
 /* Customization Settings */
 .modal {
   position: fixed;
-  z-index: 1000;
+  z-index: 20001;
   left: 0;
   top: 0;
   width: 100%;
@@ -229,7 +329,7 @@ button:hover {
 }
 
 .modal-content {
-  background-color: #797979;
+  background-color: #717171;
   padding: 20px;
   border: 1px solid #797979;
   border-radius: 10px;
@@ -249,6 +349,33 @@ button:hover {
   color: #ffffff;
 }
 
+/* Modal actions/buttons */
+.modal-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: 10px;
+}
+
+.btn-primary {
+  background-color: var(--primary-accent);
+  color: #1a1a1a;
+}
+
+.btn-primary:hover {
+  background-color: var(--primary-accent-dark);
+}
+
+.btn-secondary {
+  background-color: #e0e0e0;
+}
+
+@media (prefers-color-scheme: dark) {
+  .btn-secondary {
+    background-color: #3a3a3a;
+    color: #ffffff;
+  }
+}
+
 #terrain-toggle {
   accent-color: #fecc44;
 }
@@ -281,6 +408,10 @@ button:hover {
   margin: 15px 0;
 }
 
+#telemetry-toggle {
+  accent-color: #fecc44;
+}
+
 .scale-slider-container label {
   display: block;
   margin-bottom: 5px;
@@ -306,7 +437,7 @@ button:hover {
 
 #bbox-coords {
   width: 100%;
-  padding: 8px;
+  padding: 5px;
   border: 1px solid #fecc44;
   border-radius: 4px;
   font-size: 14px;
@@ -318,6 +449,20 @@ button:hover {
   box-shadow: 0 0 5px #fecc44;
 }
 
+#save-path {
+  width: 100%;
+  padding: 5px;
+  border: 1px solid #fecc44;
+  border-radius: 4px;
+  font-size: 14px;
+}
+
+#save-path:focus {
+  outline: none;
+  border-color: #fecc44;
+  box-shadow: 0 0 5px #fecc44;
+}
+
 /* Settings Modal Layout */
 .settings-row {
   display: flex;
@@ -329,6 +474,75 @@ button:hover {
 .settings-row label {
   text-align: left;
   flex: 1;
+  display: flex;
+  align-items: center;
+  gap: 6px;
+}
+
+/* Tooltip icon (question mark in circle) */
+.tooltip-icon {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 16px;
+  height: 16px;
+  border-radius: 50%;
+  background-color: rgba(254, 204, 68, 0.3);
+  color: #fecc44;
+  font-size: 11px;
+  font-weight: bold;
+  cursor: help;
+  position: relative;
+  flex-shrink: 0;
+}
+
+.tooltip-icon:hover {
+  background-color: rgba(254, 204, 68, 0.5);
+}
+
+/* Arnis-styled tooltip box */
+.tooltip-icon::after {
+  content: attr(data-tooltip);
+  position: absolute;
+  left: 50%;
+  bottom: calc(100% + 8px);
+  transform: translateX(-50%);
+  background-color: #2a2a2a;
+  color: #fecc44;
+  padding: 6px 14px;
+  border-radius: 6px;
+  font-size: 12px;
+  font-weight: normal;
+  white-space: nowrap;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
+  border: 1px solid #fecc44;
+  opacity: 0;
+  visibility: hidden;
+  transition: opacity 0.2s ease, visibility 0.2s ease;
+  z-index: 1000;
+  pointer-events: none;
+}
+
+/* Tooltip arrow */
+.tooltip-icon::before {
+  content: '';
+  position: absolute;
+  left: 50%;
+  bottom: calc(100% + 2px);
+  transform: translateX(-50%);
+  border: 6px solid transparent;
+  border-top-color: #fecc44;
+  opacity: 0;
+  visibility: hidden;
+  transition: opacity 0.2s ease, visibility 0.2s ease;
+  z-index: 1001;
+  pointer-events: none;
+}
+
+.tooltip-icon:hover::after,
+.tooltip-icon:hover::before {
+  opacity: 1;
+  visibility: visible;
 }
 
 .settings-control {
@@ -353,7 +567,7 @@ button:hover {
 
 .license-button-row {
   justify-content: center;
-  margin-top: 10px;
+  margin-top: 5px;
 }
 
 .license-button {
@@ -389,11 +603,39 @@ button:hover {
   box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
 }
 
+/* Generation mode dropdown styling */
+.generation-mode-dropdown {
+  width: 100%;
+  max-width: 180px;
+  padding: 3px 8px;
+  border-radius: 4px;
+  border: 1px solid #fecc44;
+  background-color: #ffffff;
+  color: #0f0f0f;
+  appearance: menulist;
+  cursor: pointer;
+  font-size: 15px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+}
+
+.generation-mode-dropdown option {
+  padding: 5px;
+  font-size: 15px;
+}
+
+@media (prefers-color-scheme: dark) {
+  .generation-mode-dropdown {
+    background-color: #0f0f0f98;
+    color: #ffffff;
+    border: 1px solid #fecc44;
+  }
+}
+
 /* Language dropdown styling */
 .language-dropdown {
   width: 100%;
   max-width: 180px;
-  padding: 5px 8px;
+  padding: 3px 8px;
   border-radius: 4px;
   border: 1px solid #fecc44;
   background-color: #ffffff;
@@ -421,7 +663,7 @@ button:hover {
 .theme-dropdown {
   width: 100%;
   max-width: 180px;
-  padding: 5px 8px;
+  padding: 3px 8px;
   border-radius: 4px;
   border: 1px solid #fecc44;
   background-color: #ffffff;
@@ -476,9 +718,12 @@ button:hover {
   transition: background-color 0.3s, border-color 0.3s;
 }
 
-.settings-button .gear-icon::before {
-  content: "⚙️";
-  font-size: 18px;
+.settings-button svg {
+  stroke: white;
+  width: 22px;
+  height: 22px;
+  min-width: 22px;
+  min-height: 22px;
 }
 
 /* Logo Animation */

src/gui/index.html

@@ -14,55 +14,57 @@
 <body>
   <main class="container">
     <div class="row">
-      <a href="https://github.com/louis-e/arnis" target="_blank">
+      <a href="https://arnismc.com" target="_blank">
         <img src="./images/logo.png" id="arnis-logo" class="logo arnis" alt="Arnis Logo" style="width: 35%; height: auto;">
       </a>
     </div>
 
     <div class="flex-container">
-      <!-- Left Box: Map and BBox Input -->
-      <section class="section map-box" style="margin-bottom: 0; padding-bottom: 0;">
-        <h2 data-localize="select_location">Select Location</h2>
-        <span id="bbox-text" style="font-size: 1.0em; display: block; margin-top: -8px; margin-bottom: 3px;" data-localize="zoom_in_and_choose">
-          Zoom in and choose your area using the rectangle tool
-        </span>
-        <iframe src="maps.html" width="100%" height="300" class="map-container" title="Map Picker"></iframe>
-
-        <span id="bbox-info"
-          style="font-size: 0.75em; color: #7bd864; display: block; margin-bottom: 4px; font-weight: bold; min-height: 2em;"></span>
+      <!-- Left Box: Map -->
+      <section class="section map-box">
+        <iframe src="maps.html" width="100%" height="100%" class="map-container" title="Map Picker"></iframe>
       </section>
 
       <!-- Right Box: Directory Selection, Start Button, and Progress Bar -->
       <section class="section controls-box">
         <div class="controls-content">
-          <h2 data-localize="select_world">Select World</h2>
-
-          <!-- Updated Tooltip Structure -->
-          <div class="tooltip" style="width: 100%;">
-            <button type="button" onclick="openWorldPicker()" style="padding: 10px; line-height: 1.2; width: 100%;">
-              <span id="choose_world">Choose World</span>
-              <br>
-              <span id="selected-world" style="font-size: 0.8em; color: #fecc44; display: block; margin-top: 4px;" data-localize="no_world_selected">
-                No world selected
-              </span>
-            </button>
+          <div class="controls-top">
+            <!-- World Selection Container -->
+            <div class="world-selection-container">
+              <div class="tooltip" style="width: 100%;">
+                <button type="button" id="choose-world-btn" onclick="openWorldPicker()" class="choose-world-btn">
+                  <span id="choose_world">Choose World</span>
+                  <br>
+                  <span id="selected-world" style="font-size: 0.8em; color: #fecc44; display: block; margin-top: 4px;" data-localize="no_world_selected">
+                    No world selected
+                  </span>
+                </button>
+              </div>
+              <!-- World Format Toggle -->
+              <div class="format-toggle-container">
+                <button type="button" id="format-java" class="format-toggle-btn format-active" onclick="setWorldFormat('java')">
+                  Java
+                </button>
+                <button type="button" id="format-bedrock" class="format-toggle-btn" onclick="setWorldFormat('bedrock')">
+                  Bedrock
+                </button>
+              </div>
+            </div>
+            
+            <div class="button-container">
+              <button type="button" id="start-button" class="start-button" onclick="startGeneration()" data-localize="start_generation">Start Generation</button>
+              <button type="button" class="settings-button" onclick="openSettings()" aria-label="Settings">
+                  <svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M12.22 2h-.44a2 2 0 0 0-2 2v.18a2 2 0 0 1-1 1.73l-.43.25a2 2 0 0 1-2 0l-.15-.08a2 2 0 0 0-2.73.73l-.22.38a2 2 0 0 0 .73 2.73l.15.1a2 2 0 0 1 1 1.72v.51a2 2 0 0 1-1 1.74l-.15.09a2 2 0 0 0-.73 2.73l.22.38a2 2 0 0 0 2.73.73l.15-.08a2 2 0 0 1 2 0l.43.25a2 2 0 0 1 1 1.73V20a2 2 0 0 0 2 2h.44a2 2 0 0 0 2-2v-.18a2 2 0 0 1 1-1.73l.43-.25a2 2 0 0 1 2 0l.15.08a2 2 0 0 0 2.73-.73l.22-.39a2 2 0 0 0-.73-2.73l-.15-.08a2 2 0 0 1-1-1.74v-.5a2 2 0 0 1 1-1.74l.15-.09a2 2 0 0 0 .73-2.73l-.22-.38a2 2 0 0 0-2.73-.73l-.15.08a2 2 0 0 1-2 0l-.43-.25a2 2 0 0 1-1-1.73V4a2 2 0 0 0-2-2z"></path><circle cx="12" cy="12" r="3"></circle></svg>
+              </button>
+            </div>
           </div>
-          
-          <div class="button-container">
-            <button type="button" id="start-button" class="start-button" onclick="startGeneration()" data-localize="start_generation">Start Generation</button>
-            <button type="button" class="settings-button" onclick="openSettings()">
-                <i class="gear-icon"></i>
-            </button>
-          </div>
-          <br><br>
 
           <div class="progress-section">
-            <h2 data-localize="progress">Progress</h2>
-            <div class="progress-bar-container">
-              <div class="progress-bar" id="progress-bar"></div>
-            </div>
-            <div class="progress-status">
-              <span id="progress-message"></span>
+            <span id="bbox-info" class="bbox-info-text" data-localize="select_area_prompt">Select an area on the map using the tools.</span>
+            <div class="progress-row">
+              <div class="progress-bar-container">
+                <div class="progress-bar" id="progress-bar"></div>
+              </div>
               <span id="progress-detail">0%</span>
             </div>
           </div>
@@ -87,33 +89,49 @@
         <span class="close-button" onclick="closeSettings()">&times;</span>
         <h2 data-localize="customization_settings">Customization Settings</h2>
 
-        <!-- Terrain Toggle Button -->
+        <!-- Generation Mode Dropdown -->
         <div class="settings-row">
-          <label for="terrain-toggle" data-localize="terrain">Terrain</label>
+          <label for="generation-mode-select">
+            <span data-localize="generation_mode">Generation Mode</span>
+            <span class="tooltip-icon" data-tooltip="Choose what to generate: buildings/roads with terrain, just objects, or terrain only">?</span>
+          </label>
           <div class="settings-control">
-            <input type="checkbox" id="terrain-toggle" name="terrain-toggle" checked>
-          </div>
-        </div>
-
-        <!-- Interior Toggle Button -->
-        <div class="settings-row">
-          <label for="interior-toggle" data-localize="interior">Interior Generation</label>
-          <div class="settings-control">
-            <input type="checkbox" id="interior-toggle" name="interior-toggle" checked>
+            <select id="generation-mode-select" name="generation-mode-select" class="generation-mode-dropdown">
+              <option value="geo-terrain" data-localize="mode_geo_terrain">Objects + Terrain</option>
+              <option value="geo-only" data-localize="mode_geo_only">Objects only</option>
+              <option value="terrain-only" data-localize="mode_terrain_only">Terrain only</option>
+            </select>
           </div>
         </div>
 
         <!-- Roof Toggle Button -->
         <div class="settings-row">
-          <label for="roof-toggle" data-localize="roof">Roof Generation</label>
+          <label for="roof-toggle">
+            <span data-localize="roof">Roof Generation</span>
+            <span class="tooltip-icon" data-tooltip="Generate roofs on buildings">?</span>
+          </label>
           <div class="settings-control">
             <input type="checkbox" id="roof-toggle" name="roof-toggle" checked>
           </div>
         </div>
 
+        <!-- Interior Toggle Button -->
+        <div class="settings-row">
+          <label for="interior-toggle">
+            <span data-localize="interior">Interior Generation</span>
+            <span class="tooltip-icon" data-tooltip="Generate interior details inside buildings">?</span>
+          </label>
+          <div class="settings-control">
+            <input type="checkbox" id="interior-toggle" name="interior-toggle">
+          </div>
+        </div>
+
         <!-- Fill ground Toggle Button -->
         <div class="settings-row">
-          <label for="fillground-toggle" data-localize="fillground">Fill Ground</label>
+          <label for="fillground-toggle">
+            <span data-localize="fillground">Fill Ground</span>
+            <span class="tooltip-icon" data-tooltip="Fill the ground below the surface">?</span>
+          </label>
           <div class="settings-control">
             <input type="checkbox" id="fillground-toggle" name="fillground-toggle">
           </div>
@@ -121,7 +139,10 @@
 
         <!-- World Scale Slider -->
         <div class="settings-row">
-          <label for="scale-value-slider" data-localize="world_scale">World Scale</label>
+          <label for="scale-value-slider">
+            <span data-localize="world_scale">World Scale</span>
+            <span class="tooltip-icon" data-tooltip="Scale factor for the generated world (1.0 = real-world scale)">?</span>
+          </label>
           <div class="settings-control">
             <input type="range" id="scale-value-slider" name="scale-value-slider" min="0.30" max="2.5" step="0.1" value="1">
             <span id="slider-value">1.00</span>
@@ -130,23 +151,21 @@
 
         <!-- Bounding Box Input -->
         <div class="settings-row">
-          <label for="bbox-coords" data-localize="custom_bounding_box">Custom Bounding Box</label>
+          <label for="bbox-coords">
+            <span data-localize="custom_bounding_box">Custom Bounding Box</span>
+            <span class="tooltip-icon" data-tooltip="Manually enter coordinates (lat,lng,lat,lng) or use map selection">?</span>
+          </label>
           <div class="settings-control">
             <input type="text" id="bbox-coords" name="bbox-coords" maxlength="55" placeholder="Format: lat,lng,lat,lng">
           </div>
         </div>
 
-        <!-- Floodfill Timeout Input -->
-        <div class="settings-row">
-          <label for="floodfill-timeout" data-localize="floodfill_timeout">Floodfill Timeout (sec)</label>
-          <div class="settings-control">
-            <input type="number" id="floodfill-timeout" name="floodfill-timeout" min="0" step="1" value="20" placeholder="Seconds">
-          </div>
-        </div>
-
         <!-- Map Theme Selector -->
         <div class="settings-row">
-          <label for="tile-theme-select" data-localize="map_theme">Map Theme</label>
+          <label for="tile-theme-select">
+            <span data-localize="map_theme">Map Theme</span>
+            <span class="tooltip-icon" data-tooltip="Visual style of the map picker">?</span>
+          </label>
           <div class="settings-control">
             <select id="tile-theme-select" name="tile-theme-select" class="theme-dropdown">
               <option value="osm">Standard</option>
@@ -160,7 +179,10 @@
 
         <!-- Language Selector -->
         <div class="settings-row">
-          <label for="language-select" data-localize="language">Language</label>
+          <label for="language-select">
+            <span data-localize="language">Language</span>
+            <span class="tooltip-icon" data-tooltip="Interface language">?</span>
+          </label>
           <div class="settings-control">
             <select id="language-select" name="language-select" class="language-dropdown">
               <option value="en">English</option>
@@ -171,6 +193,7 @@
               <option value="zh-CN">中文 (简体)</option>
               <option value="ko">한국어</option>
               <option value="pl">Polski</option>
+              <option value="lv">Latviešu</option>
               <option value="sv">Svenska</option>
               <option value="ar">العربية</option>
               <option value="fi">Suomi</option>
@@ -181,6 +204,17 @@
           </div>
         </div>
 
+        <!-- Telemetry Consent Toggle -->
+        <div class="settings-row">
+          <label for="telemetry-toggle" style="white-space: nowrap;">
+            <span>Anonymous Crash Reports</span>
+            <span class="tooltip-icon" data-tooltip="Send anonymous crash data to help improve Arnis">?</span>
+          </label>
+          <div class="settings-control">
+            <input type="checkbox" id="telemetry-toggle" name="telemetry-toggle">
+          </div>
+        </div>
+
         <!-- License and Credits Button -->
         <div class="settings-row license-button-row">
           <button type="button" id="license-button" class="license-button" onclick="openLicense()" data-localize="license_and_credits">License and Credits</button>
@@ -198,6 +232,22 @@
       </div>
     </div>
 
+    <!-- Telemetry Consent Modal (first run) -->
+    <div id="telemetry-modal" class="modal" style="display: none;">
+      <div class="modal-content">
+        <span class="close-button" onclick="rejectTelemetry()">&times;</span>
+        <h2>Help improve Arnis</h2>
+        <p style="text-align:left; margin-top:6px; color:#ececec;">
+          We’d like to collect anonymous usage data like crashes and performance to make Arnis more stable and faster.
+          <a href="https://arnismc.com/privacypolicy.html" style="color: inherit;" target="_blank">No personal data or world contents are collected.</a>
+        </p>
+        <div class="modal-actions" style="margin-top:14px;">
+          <button type="button" class="btn-secondary" onclick="rejectTelemetry()">No thanks</button>
+          <button type="button" class="btn-primary" onclick="acceptTelemetry()">Allow anonymous data</button>
+        </div>
+      </div>
+    </div>
+
     <!-- License Modal -->
     <div id="license-modal" class="modal" style="display: none;">
       <div class="modal-content">

src/gui/js/bbox.js

@@ -529,7 +529,7 @@ $(document).ready(function () {
                 failureCount++;
 
                 // After a few failures, try HTTP fallback
-                if (failureCount >= 3 && !this._httpFallbackAttempted && theme.url.startsWith('https://')) {
+                if (failureCount >= 6 && !this._httpFallbackAttempted && theme.url.startsWith('https://')) {
                     console.log('HTTPS tile loading failed, attempting HTTP fallback for', themeKey);
                     this._httpFallbackAttempted = true;
 
@@ -558,11 +558,235 @@ $(document).ready(function () {
     var savedTheme = localStorage.getItem('selectedTileTheme') || 'osm';
     changeTileTheme(savedTheme);
 
-    // Listen for theme changes from parent window (settings modal)
+    // World overlay state
+    var worldOverlay = null;
+    var worldOverlayData = null;
+    var worldOverlayEnabled = false;
+    var worldPreviewAvailable = false;
+    var sliderControl = null;
+    var worldOverlayHiddenForEdit = false; // Track if we hid the overlay for edit/delete mode
+
+    // Create the opacity slider as a proper Leaflet control
+    var SliderControl = L.Control.extend({
+        options: { position: 'topleft' },
+        onAdd: function(map) {
+            var container = L.DomUtil.create('div', 'leaflet-bar world-preview-slider-container');
+            container.id = 'world-preview-slider-container';
+            container.style.display = 'none';
+
+            var slider = L.DomUtil.create('input', 'world-preview-slider', container);
+            slider.type = 'range';
+            slider.min = '0';
+            slider.max = '100';
+            slider.value = '50';
+            slider.id = 'world-preview-opacity';
+            slider.title = 'Overlay Opacity';
+
+            L.DomEvent.on(slider, 'input', function(e) {
+                if (worldOverlay) {
+                    worldOverlay.setOpacity(e.target.value / 100);
+                }
+            });
+
+            // Prevent all map interactions
+            L.DomEvent.disableClickPropagation(container);
+            L.DomEvent.disableScrollPropagation(container);
+            L.DomEvent.on(container, 'mousedown', L.DomEvent.stopPropagation);
+            L.DomEvent.on(container, 'touchstart', L.DomEvent.stopPropagation);
+            L.DomEvent.on(slider, 'mousedown', L.DomEvent.stopPropagation);
+            L.DomEvent.on(slider, 'touchstart', L.DomEvent.stopPropagation);
+
+            return container;
+        }
+    });
+
+    // Function to add world preview button to the draw control's edit toolbar
+    function addWorldPreviewToEditToolbar() {
+        // Find the edit toolbar (contains Edit layers and Delete layers buttons)
+        var editToolbar = document.querySelector('.leaflet-draw-toolbar:not(.leaflet-draw-toolbar-top)');
+        if (!editToolbar) {
+            // Try finding by the edit/delete buttons
+            var deleteBtn = document.querySelector('.leaflet-draw-edit-remove');
+            if (deleteBtn) {
+                editToolbar = deleteBtn.parentElement;
+            }
+        }
+
+        if (editToolbar) {
+            // Create the preview button
+            var toggleBtn = document.createElement('a');
+            toggleBtn.className = 'leaflet-draw-edit-preview disabled';
+            toggleBtn.href = '#';
+            toggleBtn.title = 'Show World Preview (not available yet)';
+            toggleBtn.id = 'world-preview-btn';
+
+            toggleBtn.addEventListener('click', function(e) {
+                e.preventDefault();
+                e.stopPropagation();
+                if (worldPreviewAvailable) {
+                    toggleWorldOverlay();
+                }
+            });
+
+            editToolbar.appendChild(toggleBtn);
+
+            // Add the slider control to the map
+            sliderControl = new SliderControl();
+            map.addControl(sliderControl);
+        }
+    }
+
+    // Toggle world overlay function
+    function toggleWorldOverlay() {
+        if (!worldPreviewAvailable || !worldOverlayData) return;
+
+        worldOverlayEnabled = !worldOverlayEnabled;
+        var btn = document.getElementById('world-preview-btn');
+        var sliderContainer = document.getElementById('world-preview-slider-container');
+
+        if (worldOverlayEnabled) {
+            // Show overlay
+            var data = worldOverlayData;
+            var bounds = L.latLngBounds(
+                [data.min_lat, data.min_lon],
+                [data.max_lat, data.max_lon]
+            );
+
+            if (worldOverlay) {
+                map.removeLayer(worldOverlay);
+            }
+
+            var opacity = document.getElementById('world-preview-opacity');
+            var opacityValue = opacity ? opacity.value / 100 : 0.5;
+
+            worldOverlay = L.imageOverlay(data.image_base64, bounds, {
+                opacity: opacityValue,
+                interactive: false,
+                zIndex: 500
+            });
+            worldOverlay.addTo(map);
+
+            if (btn) {
+                btn.classList.add('active');
+                btn.title = 'Hide World Preview';
+            }
+            if (sliderContainer) {
+                sliderContainer.style.display = 'block';
+            }
+        } else {
+            // Hide overlay
+            if (worldOverlay) {
+                map.removeLayer(worldOverlay);
+                worldOverlay = null;
+            }
+            if (btn) {
+                btn.classList.remove('active');
+                btn.title = 'Show World Preview';
+            }
+            if (sliderContainer) {
+                sliderContainer.style.display = 'none';
+            }
+        }
+    }
+
+    // Enable the preview button when data is available
+    function enableWorldPreview(data) {
+        worldOverlayData = data;
+        worldPreviewAvailable = true;
+        var btn = document.getElementById('world-preview-btn');
+        if (btn) {
+            btn.classList.remove('disabled');
+            btn.title = 'Show World Preview';
+        }
+    }
+
+    // Disable and reset preview (when world changes)
+    function disableWorldPreview() {
+        worldPreviewAvailable = false;
+        worldOverlayData = null;
+        worldOverlayEnabled = false;
+
+        if (worldOverlay) {
+            map.removeLayer(worldOverlay);
+            worldOverlay = null;
+        }
+
+        var btn = document.getElementById('world-preview-btn');
+        var sliderContainer = document.getElementById('world-preview-slider-container');
+        if (btn) {
+            btn.classList.add('disabled');
+            btn.classList.remove('active');
+            btn.title = 'Show World Preview (not available yet)';
+        }
+        if (sliderContainer) {
+            sliderContainer.style.display = 'none';
+        }
+    }
+
+    // Temporarily hide the overlay (for edit/delete mode)
+    function hideWorldOverlayTemporarily() {
+        if (worldOverlay && worldOverlayEnabled) {
+            worldOverlayHiddenForEdit = true;
+            map.removeLayer(worldOverlay);
+        }
+        // Also visually disable the preview button during edit/delete mode
+        var btn = document.getElementById('world-preview-btn');
+        if (btn) {
+            btn.classList.add('editing-mode');
+        }
+    }
+
+    // Restore the overlay after edit/delete mode ends
+    function restoreWorldOverlay() {
+        if (worldOverlayHiddenForEdit && worldOverlay && worldOverlayEnabled) {
+            worldOverlay.addTo(map);
+            worldOverlayHiddenForEdit = false;
+        }
+        // Re-enable the preview button
+        var btn = document.getElementById('world-preview-btn');
+        if (btn) {
+            btn.classList.remove('editing-mode');
+        }
+    }
+
+    // Listen for messages from parent window
     window.addEventListener('message', function(event) {
         if (event.data && event.data.type === 'changeTileTheme') {
             changeTileTheme(event.data.theme);
         }
+
+        // Handle world preview data ready (after generation completes)
+        if (event.data && event.data.type === 'worldPreviewReady') {
+            enableWorldPreview(event.data.data);
+
+            // Auto-enable the overlay when generation completes
+            if (!worldOverlayEnabled) {
+                toggleWorldOverlay();
+            }
+        }
+
+        // Handle existing world map load (zoom to location and auto-enable)
+        if (event.data && event.data.type === 'loadExistingWorldMap') {
+            var data = event.data.data;
+            enableWorldPreview(data);
+
+            // Calculate bounds and zoom to them
+            var bounds = L.latLngBounds(
+                [data.min_lat, data.min_lon],
+                [data.max_lat, data.max_lon]
+            );
+            map.fitBounds(bounds, { padding: [50, 50] });
+
+            // Auto-enable the overlay
+            if (!worldOverlayEnabled) {
+                toggleWorldOverlay();
+            }
+        }
+
+        // Handle world changed (disable preview)
+        if (event.data && event.data.type === 'worldChanged') {
+            disableWorldPreview();
+        }
     });
 
     // Set the dropdown value in parent window if it exists
@@ -652,6 +876,9 @@ $(document).ready(function () {
         }
     });
     map.addControl(drawControl);
+
+    // Add world preview button to the edit toolbar after drawControl is added
+    addWorldPreviewToEditToolbar();
     /*
     **
     **  create bounds layer
@@ -699,6 +926,15 @@ $(document).ready(function () {
             });
         }
 
+        // If it's a rectangle, remove any existing rectangles first
+        if (e.layerType === 'rectangle') {
+            drawnItems.eachLayer(function(layer) {
+                if (layer instanceof L.Rectangle) {
+                    drawnItems.removeLayer(layer);
+                }
+            });
+        }
+
         // Check if it's a rectangle and set proper styles before adding it to the layer
         if (e.layerType === 'rectangle') {
             e.layer.setStyle({
@@ -790,6 +1026,23 @@ $(document).ready(function () {
         map.fitBounds(bounds.getBounds());
     });
 
+    // Hide world preview overlay when entering edit or delete mode
+    map.on('draw:editstart', function() {
+        hideWorldOverlayTemporarily();
+    });
+
+    map.on('draw:deletestart', function() {
+        hideWorldOverlayTemporarily();
+    });
+
+    // Restore world preview overlay when exiting edit or delete mode
+    map.on('draw:editstop', function() {
+        restoreWorldOverlay();
+    });
+
+    map.on('draw:deletestop', function() {
+        restoreWorldOverlay();
+    });
     function display() {
         $('#boxbounds').text(formatBounds(bounds.getBounds(), '4326'));
         $('#boxboundsmerc').text(formatBounds(bounds.getBounds(), currentproj));