SceneModel changes (#3559)

* Expose GetBoneVelocity
* Document SceneModel.Bones, expose HasBoneOverrides
* Fix spelling
* GetBoneVelocity( int ), fix GetBoneVelocities assert

---------

Co-authored-by: yuberee <59583743+yuberee@users.noreply.github.com>

engine/Sandbox.Engine/Scene/Components/Render/SkinnedModelRenderer.Bones.cs

@@ -196,11 +196,11 @@ public sealed partial class SkinnedModelRenderer
 	public record struct BoneVelocity( Vector3 Linear, Vector3 Angular );
 
 	/// <summary>
-	/// Allocate an array of bone veloicities in world space
+	/// Allocate an array of bone velocities in world space
 	/// </summary>
 	public BoneVelocity[] GetBoneVelocities()
 	{
-		Assert.NotNull( Model, "Model should not be null when calling GetBoneTransforms" );
+		Assert.NotNull( Model, "Model should not be null when calling GetBoneVelocities" );
 
 		BoneVelocity[] transforms = new BoneVelocity[Model.BoneCount];
 
@@ -215,4 +215,18 @@ public sealed partial class SkinnedModelRenderer
 
 		return transforms;
 	}
+
+	/// <summary>
+	/// Retrieve the bone's velocities based on previous and current position
+	/// </summary>
+	public BoneVelocity GetBoneVelocity( int boneIndex )
+	{
+		Assert.NotNull( Model, "Model should not be null when calling GetBoneVelocity" );
+
+		if ( !SceneModel.IsValid() || boneIndex < 0 || boneIndex >= Model.BoneCount )
+			return default;
+
+		SceneModel.GetBoneVelocity( boneIndex, out var linear, out var angular );
+		return new BoneVelocity( linear, angular );
+	}
 }

engine/Sandbox.Engine/Systems/SceneSystem/SceneModel.Bones.cs

@@ -6,6 +6,11 @@ namespace Sandbox;
 /// </summary>
 public sealed partial class SceneModel : SceneObject
 {
+	/// <summary>
+	/// Manually override the final bone transform.
+	/// </summary>
+	/// <param name="boneIndex"></param>
+	/// <param name="transform">Local coordinates based on the SceneModel's transform</param>
 	public void SetBoneOverride( int boneIndex, in Transform transform )
 	{
 		if ( boneIndex < 0 ) return;
@@ -13,21 +18,26 @@ public sealed partial class SceneModel : SceneObject
 		animNative.SetPhysicsBone( (ushort)boneIndex, transform );
 	}
 
+	/// <summary>
+	/// Clears all bone transform overrides.
+	/// </summary>
 	public void ClearBoneOverrides()
 	{
 		animNative.ClearPhysicsBones();
 	}
 
-	internal bool HasBoneOverrides()
+	/// <summary>
+	/// Whether any bone transforms have been overridden.
+	/// </summary>
+	public bool HasBoneOverrides()
 	{
 		return animNative.HasPhysicsBones();
 	}
 
 	/// <summary>
-	/// Calculate velocity from previous and current bone transform 
-	/// (I want to expose this public but want to make sure the math is correct first)
+	/// Calculates the velocity from the previous and current bone transforms.
 	/// </summary>
-	internal void GetBoneVelocity( int boneIndex, out Vector3 linear, out Vector3 angular )
+	public void GetBoneVelocity( int boneIndex, out Vector3 linear, out Vector3 angular )
 	{
 		linear = default;
 		angular = default;