Feature: Resource Deduplication on import

Editor/Scripts/GLTFImporter.cs

@@ -85,7 +85,9 @@ private static void EnsureShadersAreLoaded()
 
 	    [Tooltip("Turn this off to create an explicit GameObject for the glTF scene. A scene root will always be created if there's more than one root node.")]
         [SerializeField] internal bool _removeEmptyRootObjects = true;
-        [SerializeField] internal float _scaleFactor = 1.0f;
+        [SerializeField] internal float _scaleFactor = 1.0f; 
+        [Tooltip("Reduces identical resources. e.g. when identical meshes are found, only one will be imported.")]
+        [SerializeField] internal DeduplicateOptions _deduplicateResources = DeduplicateOptions.None;
         [SerializeField] internal int _maximumLod = 300;
         [SerializeField] internal bool _readWriteEnabled = true;
         [SerializeField] internal bool _generateColliders = false;
@@ -915,6 +917,7 @@ private void CreateGLTFScene(GLTFImportContext context, out GameObject scene,
 			    ImportBlendShapeNames = _importBlendShapeNames,
 			    BlendShapeFrameWeight = _blendShapeFrameWeight,
 			    CameraImport = _importCamera,
+			    DeduplicateResources = _deduplicateResources,
 		    };
 
 		    using (var stream = File.OpenRead(projectFilePath))

Editor/Scripts/GLTFImporterInspector.cs

@@ -81,6 +81,7 @@ private void ModelInspectorGUI()
 			EditorGUILayout.PropertyField(serializedObject.FindProperty(nameof(GLTFImporter._removeEmptyRootObjects)));
 			EditorGUILayout.PropertyField(serializedObject.FindProperty(nameof(GLTFImporter._scaleFactor)));
 			EditorGUILayout.PropertyField(serializedObject.FindProperty(nameof(GLTFImporter._importCamera)));
+			EditorGUILayout.PropertyField(serializedObject.FindProperty(nameof(GLTFImporter._deduplicateResources)));
 			// EditorGUILayout.PropertyField(serializedObject.FindProperty(nameof(GLTFImporter._maximumLod)), new GUIContent("Maximum Shader LOD"));
 			EditorGUILayout.Separator();
 

Editor/Scripts/ShaderGraph/MaterialEditorBridge.cs

@@ -81,7 +81,7 @@ private static void OnImmutableMaterialChanged(Material material)
 			// after importing a changed material, which can be confusing. Could be caching inside PBRGraphGUI
 			AssetDatabase.Refresh();
 
-			EditorApplication.update += () =>
+			EditorApplication.delayCall += () =>
 			{
 				// Repaint Inspector, newly imported values can be different if we're not perfectly round tripping
 				foreach (var editor in ActiveEditorTracker.sharedTracker.activeEditors)

README.md

@@ -295,13 +295,13 @@ Animation components and their legacy clips can also be exported.
 
 ### KHR_animation_pointer support
 
-UnityGLTF supports exporting animations with the KHR_animation_pointer extension. 
+UnityGLTF supports importing and exporting animations with the KHR_animation_pointer extension. 
 The core glTF spec only allows animation node transforms and blend shape weights, while this extension allows animating arbitrary properties in the glTF file – 
 including material and object properties, even in custom extensions and script components.
 
 Exporting with KHR_animation_pointer can be turned on in `Project Settings > UnityGLTF` by enabling the KHR_animation_pointer plugin.
 
-> **Note:** The exported files can be viewed with Gestaltor, Babylon Sandbox, and Needle Engine, but currently not with three.js / model-viewer. See https://github.com/mrdoob/three.js/pull/24108. They can also not be reimported into UnityGLTF at this point.
+> **Note:** The exported files can be viewed with Gestaltor, Babylon Sandbox, and Needle Engine, but currently not with three.js / model-viewer. See https://github.com/mrdoob/three.js/pull/24108.
 
 ## Blend Shape Export
 
@@ -359,9 +359,8 @@ If your plugin reads/writes custom extension data, you need to also implement `G
 
 ## Known Issues
 
-- Blend shapes with in-betweens are currently not supported. 
+- Blend shape in-betweens will not be exported as glTF does not have that functionality. 
 - Support for glTF files with multiple scenes is limited. 
-- Some material options (e.g. MAOS maps) are currently not exported correctly. 
 
 ## Contributing
 

Runtime/Scripts/GLTFSceneImporter.cs

@@ -15,16 +15,22 @@
 using UnityGLTF.Loader;
 using UnityGLTF.Plugins;
 using Quaternion = UnityEngine.Quaternion;
-using Vector2 = UnityEngine.Vector2;
 using Vector3 = UnityEngine.Vector3;
-using Vector4 = UnityEngine.Vector4;
 #if !WINDOWS_UWP && !UNITY_WEBGL
 using ThreadPriority = System.Threading.ThreadPriority;
 #endif
 using WrapMode = UnityEngine.WrapMode;
 
 namespace UnityGLTF
 {
+	[Flags]
+	public enum DeduplicateOptions
+	{
+		None = 0,
+		Meshes = 1,
+		Textures = 2,
+	}
+
 	public class ImportOptions
 	{
 #pragma warning disable CS0618 // Type or member is obsolete
@@ -40,7 +46,7 @@ public class ImportOptions
 		public AnimationMethod AnimationMethod = AnimationMethod.Legacy;
 		public bool AnimationLoopTime = true;
 		public bool AnimationLoopPose = false;
-
+		public DeduplicateOptions DeduplicateResources = DeduplicateOptions.None;
 		public bool SwapUVs = false;
 		public GLTFImporterNormals ImportNormals = GLTFImporterNormals.Import;
 		public GLTFImporterNormals ImportTangents = GLTFImporterNormals.Import;
@@ -73,51 +79,7 @@ public enum AnimationMethod
 		Mecanim,
 		MecanimHumanoid,
 	}
-
-	public class UnityMeshData
-	{
-		public bool[] subMeshDataCreated;
-		public Vector3[] Vertices;
-		public Vector3[] Normals;
-		public Vector4[] Tangents;
-		public Vector2[] Uv1;
-		public Vector2[] Uv2;
-		public Vector2[] Uv3;
-		public Vector2[] Uv4;
-		public Color[] Colors;
-		public BoneWeight[] BoneWeights;
-
-		public Vector3[][] MorphTargetVertices;
-		public Vector3[][] MorphTargetNormals;
-		public Vector3[][] MorphTargetTangents;
-
-		public MeshTopology[] Topology;
-		public DrawMode[] DrawModes;
-		public int[][] Indices;
-
-		public HashSet<int> alreadyAddedAccessors = new HashSet<int>();
-		public uint[] subMeshVertexOffset;
-
-		public void Clear()
-		{
-			Vertices = null;
-			Normals = null;
-			Tangents = null;
-			Uv1 = null;
-			Uv2 = null;
-			Uv3 = null;
-			Uv4 = null;
-			Colors = null;
-			BoneWeights = null;
-			MorphTargetVertices = null;
-			MorphTargetNormals = null;
-			MorphTargetTangents = null;
-			Topology = null;
-			Indices = null;
-			subMeshVertexOffset = null;
-		}
-	}
-
+
 	public struct ImportProgress
 	{
 		public bool IsDownloaded;
@@ -496,7 +458,9 @@ public void Dispose()
 				DisposeNativeBuffers();
 
 				onLoadComplete?.Invoke(null, ExceptionDispatchInfo.Capture(ex));
-				Debug.Log(LogType.Error, $"Error loading file: {_gltfFileName}");
+				Debug.Log(LogType.Error, $"Error loading file: {_gltfFileName}" 
+				                         + System.Environment.NewLine + "Message: " + ex.Message
+				                         + System.Environment.NewLine + "StackTrace: " + ex.StackTrace);
 				throw;
 			}
 			finally
@@ -701,6 +665,24 @@ private void InitializeGltfTopLevelObject()
 
 			// Free up some Memory, Accessor contents are no longer needed
 			FreeUpAccessorContents();
+
+			if (_options.DeduplicateResources != DeduplicateOptions.None)
+			{
+				if (IsMultithreaded)
+				{
+					if (_options.DeduplicateResources.HasFlag(DeduplicateOptions.Meshes))
+						await Task.Run(CheckForMeshDuplicates, cancellationToken);
+					if (_options.DeduplicateResources.HasFlag(DeduplicateOptions.Textures))
+						await Task.Run(CheckForDuplicateImages, cancellationToken);
+				}
+				else
+				{
+					if (_options.DeduplicateResources.HasFlag(DeduplicateOptions.Meshes))
+						CheckForMeshDuplicates();
+					if (_options.DeduplicateResources.HasFlag(DeduplicateOptions.Textures))
+						CheckForDuplicateImages();
+				}
+			}
 
 			await ConstructScene(scene, showSceneObj, cancellationToken);
 

Runtime/Scripts/SceneImporter/ImporterMeshes.cs

@@ -1361,5 +1361,50 @@ private static T[][] Allocate2dArray<T>(uint x, uint y)
 			for (var i = 0; i < x; i++) result[i] = new T[y];
 			return result;
 		}
+
+		private void CheckForMeshDuplicates()
+		{
+			Dictionary<int, int> meshDuplicates = new Dictionary<int, int>();
+
+			for (int meshIndex = 0; meshIndex < _gltfRoot.Meshes.Count; meshIndex++)
+			{
+				if (meshDuplicates.ContainsKey(meshIndex))
+				    continue;
+
+				for (int i = meshIndex+1; i < _gltfRoot.Meshes.Count; i++)
+				{
+
+					if (i == meshIndex)
+						continue;
+					if (_assetCache.MeshCache[i] == null)
+						continue;
+
+					if (_assetCache.UnityMeshDataCache[i] == null
+					    || _assetCache.UnityMeshDataCache[meshIndex] == null)
+						continue;
+
+					var meshIsEqual = _assetCache.UnityMeshDataCache[i]
+						.IsEqual(_assetCache.UnityMeshDataCache[meshIndex]);
+
+					if (meshIsEqual)
+						meshDuplicates[i] = meshIndex;
+				}
+			}
+
+			foreach (var dm in meshDuplicates)
+			{
+				for (int i = 0; i < _gltfRoot.Nodes.Count; i++)
+				{
+					if (_gltfRoot.Nodes[i].Mesh != null && _gltfRoot.Nodes[i].Mesh.Id == dm.Key)
+					{
+						if (_gltfRoot.Nodes[i].Weights == null && _gltfRoot.Meshes[dm.Value].Weights != null)
+							_gltfRoot.Nodes[i].Weights = _gltfRoot.Meshes[_gltfRoot.Nodes[i].Mesh.Id].Weights;
+
+						_gltfRoot.Nodes[i].Mesh.Id = dm.Value;
+					}
+				}
+			}
+
+		}
 	}
 }