Fixed shared SkinnedMesh on export

Runtime/Scripts/GLTFSceneExporter.cs

@@ -449,7 +449,6 @@ public bool Equals(UniquePrimitive other)
 			{
 				if (!Equals(Mesh, other.Mesh)) return false;
 				if (Materials == null && other.Materials == null) return true;
-				if (!Equals(SkinnedMeshRenderer, other.SkinnedMeshRenderer)) return false;
 				if (!(Materials != null && other.Materials != null)) return false;
 				if (!Equals(Materials.Length, other.Materials.Length)) return false;
 				for (var i = 0; i < Materials.Length; i++)
@@ -470,10 +469,6 @@ public override int GetHashCode()
 				unchecked
 				{
 					var code = (Mesh != null ? Mesh.GetHashCode() : 0) * 397;
-					if (SkinnedMeshRenderer != null)
-					{
-						code = code ^ SkinnedMeshRenderer.GetHashCode() * 397;
-					}
 					if (Materials != null)
 					{
 						code = code ^ Materials.Length.GetHashCode() * 397;
@@ -1094,6 +1089,32 @@ private NodeId ExportNode(Transform nodeTransform)
 				{
 					node.Mesh = ExportMesh(nodeTransform.name, uniquePrimitives);
 					RegisterPrimitivesWithNode(node, uniquePrimitives);
+
+					// Node - BlendShape Weights 
+					if (uniquePrimitives[0].SkinnedMeshRenderer)
+					{
+						var meshObj = uniquePrimitives[0].Mesh;
+						var smr = uniquePrimitives[0].SkinnedMeshRenderer;
+						// Only export the blendShapeWeights into the Node, when it's not the first SkinnedMeshRenderer with the same Mesh
+						// Because the weights already exported into the GltfMesh
+						if (smr && meshObj && _meshToBlendShapeAccessors.TryGetValue(meshObj, out var data) && smr != data.firstSkinnedMeshRenderer)
+						{
+							var blendShapeWeights = GetBlendShapeWeights(smr, meshObj);
+							if (blendShapeWeights != null)
+							{
+								if (data.weights != null)
+								{
+									// Check if the blendShapeWeights has any differences to the weights already exported into the gltfMesh
+									// When not, we don't need to set the same values to the Node Weights
+									bool isSame = true;
+									for (int i = 0; i < blendShapeWeights.Count; i++)
+										isSame &= System.Math.Abs(blendShapeWeights[i] - data.weights[i]) < double.Epsilon;
+									if (!isSame)
+										node.Weights = blendShapeWeights;
+								}
+							}
+						}
+					}
 				}
 			}
 

Runtime/Scripts/SceneExporter/ExporterMeshes.cs

@@ -17,7 +17,7 @@ public partial class GLTFSceneExporter
 	{
 		private struct MeshAccessors
 		{
-			public AccessorId aPosition, aNormal, aTangent, aTexcoord0, aTexcoord1, aColor0;
+			public AccessorId aPosition, aNormal, aTangent, aTexcoord0, aTexcoord1, aColor0, aJoints0, aWeights0;
 			public Dictionary<int, MeshPrimitive> subMeshPrimitives;
 		}
 
@@ -26,10 +26,12 @@ private struct BlendShapeAccessors
 			public List<Dictionary<string, AccessorId>> targets;
 			public List<Double> weights;
 			public List<string> targetNames;
+			internal SkinnedMeshRenderer firstSkinnedMeshRenderer; 
 		}
 
 		private readonly Dictionary<Mesh, MeshAccessors> _meshToPrims = new Dictionary<Mesh, MeshAccessors>();
 		private readonly Dictionary<Mesh, BlendShapeAccessors> _meshToBlendShapeAccessors = new Dictionary<Mesh, BlendShapeAccessors>();
+		private readonly Dictionary<SkinnedMeshRenderer, List<double>> _NodeBlendShapeWeights = new Dictionary<SkinnedMeshRenderer, List<double>>();
 
 		public void RegisterPrimitivesWithNode(Node node, List<UniquePrimitive> uniquePrimitives)
 		{
@@ -362,6 +364,32 @@ private MeshPrimitive[] ExportPrimitive(UniquePrimitive primKey, GLTFMesh mesh)
             return prims;
 		}
 
+		private List<double> GetBlendShapeWeights(SkinnedMeshRenderer smr, Mesh meshObj)
+		{
+			if (_NodeBlendShapeWeights.TryGetValue(smr, out var w))
+				return w;
+
+			List<Double> weights = new List<double>(meshObj.blendShapeCount);
+
+			for (int blendShapeIndex = 0; blendShapeIndex < meshObj.blendShapeCount; blendShapeIndex++)
+			{
+				// We need to get the weight from the SkinnedMeshRenderer because this represents the currently
+				// defined weight by the user to apply to this blend shape.  If we instead got the value from
+				// the unityMesh, it would be a _per frame_ weight, and for a single-frame blend shape, that would
+				// always be 100.  A blend shape might have more than one frame if a user wanted to more tightly
+				// control how a blend shape will be animated during weight changes (e.g. maybe they want changes
+				// between 0-50% to be really minor, but between 50-100 to be extreme, hence they'd have two frames
+				// where the first frame would have a weight of 50 (meaning any weight between 0-50 should be relative
+				// to the values in this frame) and then any weight between 50-100 would be relevant to the weights in
+				// the second frame.  See Post 20 for more info:
+				// https://forum.unity3d.com/threads/is-there-some-method-to-add-blendshape-in-editor.298002/#post-2015679
+				var frameWeight = meshObj.GetBlendShapeFrameWeight(blendShapeIndex, 0);
+				weights.Add(smr.GetBlendShapeWeight(blendShapeIndex) / frameWeight);
+			}
+
+			return weights;
+		}
+
 		// Blend Shapes / Morph Targets
 		// Adopted from Gary Hsu (bghgary)
 		// https://github.com/bghgary/glTF-Tools-for-Unity/blob/master/UnityProject/Assets/Gltf/Editor/Exporter.cs
@@ -381,7 +409,7 @@ private void ExportBlendShapes(SkinnedMeshRenderer smr, Mesh meshObj, int submes
 			if (smr != null && meshObj.blendShapeCount > 0)
 			{
 				List<Dictionary<string, AccessorId>> targets = new List<Dictionary<string, AccessorId>>(meshObj.blendShapeCount);
-				List<Double> weights = new List<double>(meshObj.blendShapeCount);
+				List<Double> weights;
 				List<string> targetNames = new List<string>(meshObj.blendShapeCount);
 
 #if UNITY_2019_3_OR_NEWER
@@ -455,30 +483,19 @@ private void ExportBlendShapes(SkinnedMeshRenderer smr, Mesh meshObj, int submes
 							exportTargets.Add(SemanticProperties.TANGENT, ExportSparseAccessor(null, null, SchemaExtensions.ConvertVector3CoordinateSpaceAndCopy(deltaTangents, SchemaExtensions.CoordinateSpaceConversionScale)));
 						}
 					}
-					targets.Add(exportTargets);
-
-					// We need to get the weight from the SkinnedMeshRenderer because this represents the currently
-					// defined weight by the user to apply to this blend shape.  If we instead got the value from
-					// the unityMesh, it would be a _per frame_ weight, and for a single-frame blend shape, that would
-					// always be 100.  A blend shape might have more than one frame if a user wanted to more tightly
-					// control how a blend shape will be animated during weight changes (e.g. maybe they want changes
-					// between 0-50% to be really minor, but between 50-100 to be extreme, hence they'd have two frames
-					// where the first frame would have a weight of 50 (meaning any weight between 0-50 should be relative
-					// to the values in this frame) and then any weight between 50-100 would be relevant to the weights in
-					// the second frame.  See Post 20 for more info:
-					// https://forum.unity3d.com/threads/is-there-some-method-to-add-blendshape-in-editor.298002/#post-2015679
-					var frameWeight = meshObj.GetBlendShapeFrameWeight(blendShapeIndex, 0);
-					if(exportTargets.Any())
-						weights.Add(smr.GetBlendShapeWeight(blendShapeIndex) / frameWeight);
 
+					targets.Add(exportTargets);
+
 					exportBlendShapeMarker.End();
 				}
 
+				weights = GetBlendShapeWeights(smr, meshObj);
 				if(weights.Any() && targets.Any())
 				{
 					mesh.Weights = weights;
 					mesh.TargetNames = targetNames;
 					primitive.Targets = targets;
+					_NodeBlendShapeWeights.Add(smr, weights);
 				}
 				else
 				{
@@ -492,7 +509,8 @@ private void ExportBlendShapes(SkinnedMeshRenderer smr, Mesh meshObj, int submes
 				{
 					targets = targets,
 					weights = weights,
-					targetNames = targetNames
+					targetNames = targetNames,
+					firstSkinnedMeshRenderer = smr
 				});
 			}
 		}

Runtime/Scripts/SceneExporter/ExporterSkinning.cs

@@ -89,6 +89,12 @@ private void ExportSkinFromNode(Transform transform)
 				GLTF.Schema.GLTFMesh gltfMesh = _root.Meshes[val.Id];
 				if(gltfMesh != null)
 				{
+					var accessors = _meshToPrims[mesh];
+					if (accessors.aJoints0 != null)
+						sharedBones = accessors.aJoints0;
+					if (accessors.aWeights0 != null)
+						sharedWeights = accessors.aWeights0;
+
 					foreach (MeshPrimitive prim in gltfMesh.Primitives)
 					{
 						if (!prim.Attributes.ContainsKey("JOINTS_0"))
@@ -101,6 +107,8 @@ private void ExportSkinFromNode(Transform transform)
 								jointsAccessor.Value.BufferView.Value.Target = BufferViewTarget.ArrayBuffer;
 								prim.Attributes.Add("JOINTS_0", jointsAccessor);
 								sharedBones = jointsAccessor;
+								accessors.aJoints0 = jointsAccessor;
+								_meshToPrims[mesh] = accessors;
 							}
 						}
 
@@ -114,6 +122,8 @@ private void ExportSkinFromNode(Transform transform)
 								weightsAccessor.Value.BufferView.Value.Target = BufferViewTarget.ArrayBuffer;
 								prim.Attributes.Add("WEIGHTS_0", weightsAccessor);
 								sharedWeights = weightsAccessor;
+								accessors.aWeights0 = weightsAccessor;
+								_meshToPrims[mesh] = accessors;
 							}
 						}
 					}