From 94bb6f886b631a59c33c86a535afa55ea3330f8c Mon Sep 17 00:00:00 2001
From: Lorenz Junglas <4759511+lolleko@users.noreply.github.com>
Date: Thu, 11 Dec 2025 09:10:03 +0100
Subject: [PATCH] Shutdown scene early (#3576)

* Destroy ActiveScene early during game shutdown
* Don't call into native when deleting scenemaps
---
 .../Sandbox.Engine/Systems/SceneSystem/SceneMap.cs   |  2 +-
 .../Sandbox.Engine/Systems/SceneSystem/SceneWorld.cs | 12 ++++++++++--
 engine/Sandbox.GameInstance/GameInstance.cs          |  5 +++--
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/engine/Sandbox.Engine/Systems/SceneSystem/SceneMap.cs b/engine/Sandbox.Engine/Systems/SceneSystem/SceneMap.cs
index 4a138dac..2df2afae 100644
--- a/engine/Sandbox.Engine/Systems/SceneSystem/SceneMap.cs
+++ b/engine/Sandbox.Engine/Systems/SceneSystem/SceneMap.cs
@@ -210,7 +210,7 @@ public sealed partial class SceneMap : IValid
 		if ( PVS.IsValid )
 		{
 			// don't destroy if another SceneWorld is using it
-			if ( !SceneWorld.All.Where( x => x.IsValid() && x.native.GetPVS() == PVS ).Any() )
+			if ( !SceneWorld.All.Any( x => x.ActivePVS == PVS ) )
 			{
 				g_pEnginePVSManager.DestroyPvs( PVS );
 			}
diff --git a/engine/Sandbox.Engine/Systems/SceneSystem/SceneWorld.cs b/engine/Sandbox.Engine/Systems/SceneSystem/SceneWorld.cs
index e6931ac9..fc6948f9 100644
--- a/engine/Sandbox.Engine/Systems/SceneSystem/SceneWorld.cs
+++ b/engine/Sandbox.Engine/Systems/SceneSystem/SceneWorld.cs
@@ -16,6 +16,7 @@ public sealed partial class SceneWorld : IHandle
 	internal HashSet<SceneObject> InternalSceneObjects { get; set; } = new();
 	internal HashSet<SceneMap> InternalSceneMaps { get; set; } = new();
 	internal HashSet<SceneSkybox3D> InternalSkyboxWorlds { get; set; } = new();
+	internal IPVS ActivePVS { get; private set; }
 
 	/// <summary>
 	/// List of scene objects belonging to this scene world.
@@ -100,6 +101,7 @@ public sealed partial class SceneWorld : IHandle
 
 		CSceneSystem.DestroyWorld( this );
 		native = IntPtr.Zero;
+		ActivePVS = default;
 	}
 
 	internal void OnNativeInit( ISceneWorld ptr )
@@ -111,6 +113,7 @@ public sealed partial class SceneWorld : IHandle
 	internal void OnNativeDestroy()
 	{
 		native = IntPtr.Zero;
+		ActivePVS = default;
 		All.Remove( this );
 	}
 
@@ -168,6 +171,7 @@ public sealed partial class SceneWorld : IHandle
 			{
 				//Log.Info( $"{this} - SET PVS from {sceneMap}" );
 				native.SetPVS( sceneMap.PVS );
+				ActivePVS = sceneMap.PVS;
 			}
 		}
 	}
@@ -182,9 +186,13 @@ public sealed partial class SceneWorld : IHandle
 				Log.Warning( "Couldn't remove sceneMap" );
 			}
 
-			if ( native.GetPVS() == sceneMap.PVS )
+			if ( ActivePVS == sceneMap.PVS )
 			{
-				native.SetPVS( default );
+				if ( !native.IsNull )
+				{
+					native.SetPVS( default );
+				}
+				ActivePVS = default;
 			}
 		}
 	}
diff --git a/engine/Sandbox.GameInstance/GameInstance.cs b/engine/Sandbox.GameInstance/GameInstance.cs
index fd354eb0..f80a3b8b 100644
--- a/engine/Sandbox.GameInstance/GameInstance.cs
+++ b/engine/Sandbox.GameInstance/GameInstance.cs
@@ -106,6 +106,9 @@ internal partial class GameInstance : IGameInstance
 
 		_packageAssembly = null;
 
+		// Tear down the active scene while content is still mounted so native handles remain valid during cleanup
+		Game.Shutdown();
+
 		GlobalContext.Current.UISystem.Clear();
 
 		if ( activePackage != null && !Application.IsStandalone )
@@ -123,8 +126,6 @@ internal partial class GameInstance : IGameInstance
 
 		GameInstanceDll.Current.Shutdown( this );
 
-		Game.Shutdown();
-
 		// If we were running a benchmark, leave the game
 		if ( Application.IsBenchmark )
 		{