public UnityEngine.Matrix4x4[] ComputeInstanceMatrices(USD.NET.Scene scene, string primPath) { var prim = scene.GetPrimAtPath(primPath); var pi = new pxr.UsdGeomPointInstancer(prim); var xforms = new pxr.VtMatrix4dArray(); pi.ComputeInstanceTransformsAtTime(xforms, scene.Time == null ? pxr.UsdTimeCode.Default() : scene.Time, 0); // Slow, but works. var matrices = new UnityEngine.Matrix4x4[xforms.size()]; for (int i = 0; i < xforms.size(); i++) { matrices[i] = UnityTypeConverter.FromMatrix(xforms[i]); } return(matrices); }
/// <summary> /// Rebuilds the USD scene as Unity GameObjects, with a limited budget per update. /// </summary> public static IEnumerator BuildScene(Scene scene, GameObject root, SceneImportOptions importOptions, PrimMap primMap, float targetFrameMilliseconds, bool composingSubtree) { var timer = new System.Diagnostics.Stopwatch(); var usdPrimRoot = new pxr.SdfPath(importOptions.usdRootPath); // Setting an arbitrary fudge factor of 20% is very non-scientific, however it's better than // nothing. The correct way to hit a deadline is to predict how long each iteration actually // takes and then return early if the estimated time is over budget. float targetTime = targetFrameMilliseconds * .8f; timer.Start(); // Reconstruct the USD hierarchy as Unity GameObjects. // A PrimMap is returned for tracking the USD <-> Unity mapping. Profiler.BeginSample("USD: Build Hierarchy"); if (importOptions.importHierarchy || importOptions.forceRebuild) { // When a USD file is fully RE-imported, all exsiting USD data must be removed. The old // assumption was that the root would never have much more than the UsdAsset component // itself, however it's now clear that the root may also have meaningful USD data added // too. // // TODO(jcowles): This feels like a workaround. What we really want here is an "undo" // process for changes made to the root GameObject. For example, to clean up non-USD // components which may have been added (e.g. what if a mesh is imported to the root? // currently the MeshRenderer etc will remain after re-import). RemoveComponent <UsdAssemblyRoot>(root); RemoveComponent <UsdVariantSet>(root); RemoveComponent <UsdModelRoot>(root); RemoveComponent <UsdLayerStack>(root); RemoveComponent <UsdPayload>(root); RemoveComponent <UsdPrimSource>(root); primMap.Clear(); HierarchyBuilder.BuildGameObjects(scene, root, usdPrimRoot, scene.Find(usdPrimRoot.ToString(), "UsdSchemaBase"), primMap, importOptions); } Profiler.EndSample(); if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } Profiler.BeginSample("USD: Post Process Hierarchy"); foreach (var processor in root.GetComponents <IImportPostProcessHierarchy>()) { try { processor.PostProcessHierarchy(primMap, importOptions); } catch (System.Exception ex) { Debug.LogException(ex); } } Profiler.EndSample(); if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } // // Pre-process UsdSkelRoots. // var skelRoots = new List <pxr.UsdSkelRoot>(); if (importOptions.importSkinning) { Profiler.BeginSample("USD: Process UsdSkelRoots"); foreach (var path in primMap.SkelRoots) { try { var skelRootPrim = scene.GetPrimAtPath(path); if (!skelRootPrim) { Debug.LogWarning("SkelRoot prim not found: " + path); continue; } var skelRoot = new pxr.UsdSkelRoot(skelRootPrim); if (!skelRoot) { Debug.LogWarning("SkelRoot prim not SkelRoot type: " + path); continue; } skelRoots.Add(skelRoot); GameObject go = primMap[path]; ImporterBase.GetOrAddComponent <Animator>(go, true); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error pre-processing SkelRoot <" + path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); } // // Import known prim types. // // Materials. Profiler.BeginSample("USD: Build Materials"); if (importOptions.ShouldBindMaterials) { foreach (var pathAndSample in scene.ReadAll <MaterialSample>(primMap.Materials)) { try { var mat = MaterialImporter.BuildMaterial(scene, pathAndSample.path, pathAndSample.sample, importOptions); if (mat != null) { importOptions.materialMap[pathAndSample.path] = mat; } } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing material <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } } Profiler.EndSample(); // // Start threads. // ReadAllJob <XformSample> readXforms; if (importOptions.importTransforms) { readXforms = new ReadAllJob <XformSample>(scene, primMap.Xforms); #if UNITY_2018_1_OR_NEWER readXforms.Schedule(primMap.Xforms.Length, 4); #else readXforms.Run(); #endif } if (importOptions.importMeshes) { ActiveMeshImporter.BeginReading(scene, primMap); } #if UNITY_2018_1_OR_NEWER JobHandle.ScheduleBatchedJobs(); #endif // Xforms. // // Note that we are specifically filtering on XformSample, not Xformable, this way only // Xforms are processed to avoid doing that work redundantly. if (importOptions.importTransforms) { Profiler.BeginSample("USD: Build Xforms"); foreach (var pathAndSample in readXforms) { try { if (pathAndSample.path == usdPrimRoot) { // Never read the xform from the USD root, that will be authored in Unity. continue; } GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } foreach (var pathAndSample in scene.ReadAll <XformSample>(primMap.SkelRoots)) { try { if (pathAndSample.path == usdPrimRoot) { // Never read the xform from the USD root, that will be authored in Unity. continue; } GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } if (importOptions.importSkinning) { foreach (var pathAndSample in scene.ReadAll <XformSample>(primMap.Skeletons)) { try { if (pathAndSample.path == usdPrimRoot) { // Never read the xform from the USD root, that will be authored in Unity. continue; } GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } } Profiler.EndSample(); } // Meshes. if (importOptions.importMeshes) { Profiler.BeginSample("USD: Build Meshes"); IEnumerator it = ActiveMeshImporter.Import(scene, primMap, importOptions); while (it.MoveNext()) { if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); // Cubes. Profiler.BeginSample("USD: Build Cubes"); foreach (var pathAndSample in scene.ReadAll <CubeSample>(primMap.Cubes)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); CubeImporter.BuildCube(pathAndSample.sample, go, importOptions); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing cube <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); } // Cameras. if (importOptions.importCameras) { Profiler.BeginSample("USD: Cameras"); foreach (var pathAndSample in scene.ReadAll <CameraSample>(primMap.Cameras)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); // The camera has many value-type parameters that need to be handled correctly when not // not animated. For now, only the camera transform will animate, until this is fixed. if (scene.AccessMask == null || scene.IsPopulatingAccessMask) { CameraImporter.BuildCamera(pathAndSample.sample, go, importOptions); } } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing camera <" + pathAndSample.path + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); } // Build out masters for instancing. Profiler.BeginSample("USD: Build Instances"); foreach (var masterRootPath in primMap.GetMasterRootPaths()) { try { Transform masterRootXf = primMap[masterRootPath].transform; // Transforms if (importOptions.importTransforms) { Profiler.BeginSample("USD: Build Xforms"); foreach (var pathAndSample in scene.ReadAll <XformSample>(masterRootPath)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } } foreach (var pathAndSample in scene.ReadAll <XformSample>(masterRootPath)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } } foreach (var pathAndSample in scene.ReadAll <XformSample>(primMap.Skeletons)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing xform <" + pathAndSample.path + ">", ex)); } } Profiler.EndSample(); } // Meshes. if (importOptions.importMeshes) { Profiler.BeginSample("USD: Build Meshes"); foreach (var pathAndSample in scene.ReadAll <MeshSample>(masterRootPath)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); var subsets = MeshImporter.ReadGeomSubsets(scene, pathAndSample.path); MeshImporter.BuildMesh(pathAndSample.path, pathAndSample.sample, subsets, go, importOptions); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing mesh <" + pathAndSample.path + ">", ex)); } } Profiler.EndSample(); // Cubes. Profiler.BeginSample("USD: Build Cubes"); foreach (var pathAndSample in scene.ReadAll <CubeSample>(masterRootPath)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); CubeImporter.BuildCube(pathAndSample.sample, go, importOptions); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing cube <" + pathAndSample.path + ">", ex)); } } Profiler.EndSample(); } // Cameras. if (importOptions.importCameras) { Profiler.BeginSample("USD: Build Cameras"); foreach (var pathAndSample in scene.ReadAll <CameraSample>(masterRootPath)) { try { GameObject go = primMap[pathAndSample.path]; NativeImporter.ImportObject(scene, go, scene.GetPrimAtPath(pathAndSample.path), importOptions); XformImporter.BuildXform(pathAndSample.path, pathAndSample.sample, go, importOptions, scene); CameraImporter.BuildCamera(pathAndSample.sample, go, importOptions); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing camera <" + pathAndSample.path + ">", ex)); } } Profiler.EndSample(); } } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing master <" + masterRootPath + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } // Instances. Profiler.EndSample(); // // Post-process dependencies: materials and bones. // Profiler.BeginSample("USD: Process Material Bindings"); try { // TODO: Currently ProcessMaterialBindings runs too long and will go over budget for any // large scene. However, pulling the loop into this code feels wrong in terms of // responsibilities. // Process all material bindings in a single vectorized request. MaterialImporter.ProcessMaterialBindings(scene, importOptions); } catch (System.Exception ex) { Debug.LogException(new ImportException("Failed in ProcessMaterialBindings", ex)); } Profiler.EndSample(); if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } // // SkinnedMesh bone bindings. // if (importOptions.importSkinning) { Profiler.BeginSample("USD: Build Skeletons"); var skeletonSamples = new Dictionary <pxr.SdfPath, SkeletonSample>(); foreach (var skelRoot in skelRoots) { try { var bindings = new pxr.UsdSkelBindingVector(); if (!primMap.SkelBindings.TryGetValue(skelRoot.GetPath(), out bindings)) { Debug.LogWarning("No bindings found skelRoot: " + skelRoot.GetPath()); } if (bindings.Count == 0) { Debug.LogWarning("No bindings found skelRoot: " + skelRoot.GetPath()); } foreach (var skelBinding in bindings) { // The SkelRoot will likely have a skeleton binding, but it's inherited, so the bound // skeleton isn't actually known until it's queried from the binding. Still, we would // like not to reprocess skeletons redundantly, so skeletons are cached into a // dictionary. Profiler.BeginSample("Build Bind Transforms"); var skelPath = skelBinding.GetSkeleton().GetPath(); SkeletonSample skelSample = null; if (!skeletonSamples.TryGetValue(skelPath, out skelSample)) { skelSample = new SkeletonSample(); Profiler.BeginSample("Read Skeleton"); scene.Read(skelPath, skelSample); Profiler.EndSample(); skeletonSamples.Add(skelPath, skelSample); // Unity uses the inverse bindTransform, since that's actually what's needed for // skinning. Do that once here, so each skinned mesh doesn't need to do it // redundantly. SkeletonImporter.BuildBindTransforms(skelPath, skelSample, importOptions); var bindXforms = new pxr.VtMatrix4dArray(); var prim = scene.GetPrimAtPath(skelPath); var skel = new pxr.UsdSkelSkeleton(prim); Profiler.BeginSample("Get SkelQuery"); pxr.UsdSkelSkeletonQuery skelQuery = primMap.SkelCache.GetSkelQuery(skel); Profiler.EndSample(); Profiler.BeginSample("Get JointWorldBind Transforms"); if (!skelQuery.GetJointWorldBindTransforms(bindXforms)) { throw new ImportException("Failed to compute binding trnsforms for <" + skelPath + ">"); } Profiler.EndSample(); SkeletonImporter.BuildDebugBindTransforms(skelSample, primMap[skelPath], importOptions); } Profiler.EndSample(); if (importOptions.importSkinWeights) { // // Apply skinning weights to each skinned mesh. // Profiler.BeginSample("Apply Skin Weights"); foreach (var skinningQuery in skelBinding.GetSkinningTargetsAsVector()) { var meshPath = skinningQuery.GetPrim().GetPath(); try { var skelBindingSample = new SkelBindingSample(); var goMesh = primMap[meshPath]; scene.Read(meshPath, skelBindingSample); Profiler.BeginSample("Build Skinned Mesh"); SkeletonImporter.BuildSkinnedMesh( meshPath, skelPath, skelSample, skelBindingSample, goMesh, primMap, importOptions); Profiler.EndSample(); // In terms of performance, this is almost free. goMesh.GetComponent <SkinnedMeshRenderer>().rootBone = primMap[skelPath].transform.GetChild(0); } catch (System.Exception ex) { Debug.LogException(new ImportException("Error skinning mesh: " + meshPath, ex)); } } Profiler.EndSample(); } } } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing SkelRoot <" + skelRoot.GetPath() + ">", ex)); } } // foreach SkelRoot Profiler.EndSample(); if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } // // Bone transforms. // Profiler.BeginSample("USD: Pose Bones"); foreach (var pathAndSample in skeletonSamples) { var skelPath = pathAndSample.Key; try { var prim = scene.GetPrimAtPath(skelPath); var skel = new pxr.UsdSkelSkeleton(prim); pxr.UsdSkelSkeletonQuery skelQuery = primMap.SkelCache.GetSkelQuery(skel); var joints = skelQuery.GetJointOrder(); var restXforms = new pxr.VtMatrix4dArray(); var time = scene.Time.HasValue ? scene.Time.Value : pxr.UsdTimeCode.Default(); Profiler.BeginSample("Compute Joint Local Transforms"); if (!skelQuery.ComputeJointLocalTransforms(restXforms, time, atRest: false)) { throw new ImportException("Failed to compute bind trnsforms for <" + skelPath + ">"); } Profiler.EndSample(); Profiler.BeginSample("Build Bones"); for (int i = 0; i < joints.size(); i++) { var jointPath = scene.GetSdfPath(joints[i]); if (joints[i] == "/") { jointPath = skelPath; } else if (jointPath.IsAbsolutePath()) { Debug.LogException(new System.Exception("Unexpected absolute joint path: " + jointPath)); jointPath = new pxr.SdfPath(joints[i].ToString().TrimStart('/')); jointPath = skelPath.AppendPath(jointPath); } else { jointPath = skelPath.AppendPath(jointPath); } var goBone = primMap[jointPath]; Profiler.BeginSample("Convert Matrix"); var restXform = UnityTypeConverter.FromMatrix(restXforms[i]); Profiler.EndSample(); Profiler.BeginSample("Build Bone"); SkeletonImporter.BuildSkeletonBone(skelPath, goBone, restXform, joints, importOptions); Profiler.EndSample(); } Profiler.EndSample(); } catch (System.Exception ex) { Debug.LogException( new ImportException("Error processing SkelRoot <" + skelPath + ">", ex)); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); } // // Apply instancing. // if (importOptions.importSceneInstances) { Profiler.BeginSample("USD: Build Scene-Instances"); try { // Build scene instances. InstanceImporter.BuildSceneInstances(primMap, importOptions); } catch (System.Exception ex) { Debug.LogException(new ImportException("Failed in BuildSceneInstances", ex)); } Profiler.EndSample(); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } // Build point instances. if (importOptions.importPointInstances) { Profiler.BeginSample("USD: Build Point-Instances"); // TODO: right now all point instancer data is read, but we only need prototypes and indices. foreach (var pathAndSample in scene.ReadAll <PointInstancerSample>()) { try { GameObject instancerGo = primMap[pathAndSample.path]; // Now build the point instances. InstanceImporter.BuildPointInstances(scene, primMap, pathAndSample.path, pathAndSample.sample, instancerGo, importOptions); } catch (System.Exception ex) { Debug.LogError("Error processing point instancer <" + pathAndSample.path + ">: " + ex.Message); } if (ShouldYield(targetTime, timer)) { yield return(null); ResetTimer(timer); } } Profiler.EndSample(); } // // Apply root transform corrections. // Profiler.BeginSample("USD: Build Root Transforms"); if (!composingSubtree) { if (!root) { // There is no single root, // Apply root transform corrections to all imported root prims. foreach (KeyValuePair <pxr.SdfPath, GameObject> kvp in primMap) { if (kvp.Key.IsRootPrimPath() && kvp.Value != null) { // The root object at which the USD scene will be reconstructed. // It may need a Z-up to Y-up conversion and a right- to left-handed change of basis. XformImporter.BuildSceneRoot(scene, kvp.Value.transform, importOptions); } } } else { // There is only one root, apply a single transform correction. XformImporter.BuildSceneRoot(scene, root.transform, importOptions); } } Profiler.EndSample(); Profiler.BeginSample("USD: Post Process Components"); foreach (var processor in root.GetComponents <IImportPostProcessComponents>()) { try { processor.PostProcessComponents(primMap, importOptions); } catch (System.Exception ex) { Debug.LogException(ex); } } Profiler.EndSample(); }
public static void BuildSkinnedMesh(string meshPath, string skelPath, SkeletonSample skeleton, UsdSkelSkinningQuery skinningQuery, GameObject go, PrimMap primMap, SceneImportOptions options) { // The mesh renderer must already exist, since hte mesh also must already exist. var smr = go.GetComponent <SkinnedMeshRenderer>(); if (!smr) { throw new Exception( "Error importing " + meshPath + " SkinnnedMeshRenderer not present on GameObject" ); } // Get and validate the joint weights and indices informations. UsdGeomPrimvar jointWeights = skinningQuery.GetJointWeightsPrimvar(); UsdGeomPrimvar jointIndices = skinningQuery.GetJointIndicesPrimvar(); if (!jointWeights.IsDefined() || !jointIndices.IsDefined()) { throw new Exception("Joints information (indices and/or weights) are missing for: " + meshPath); } // TODO: Both indices and weights attributes can be animated. It's not handled yet. // TODO: Having something that convert a UsdGeomPrimvar into a PrimvarSample could help simplify this code. int[] indices = IntrinsicTypeConverter.FromVtArray((VtIntArray)jointIndices.GetAttr().Get()); int indicesElementSize = jointIndices.GetElementSize(); pxr.TfToken indicesInterpolation = jointIndices.GetInterpolation(); if (indices.Length == 0 || indicesElementSize == 0 || indices.Length % indicesElementSize != 0 || !pxr.UsdGeomPrimvar.IsValidInterpolation(indicesInterpolation)) { throw new Exception("Joint indices information are invalid or empty for: " + meshPath); } float[] weights = IntrinsicTypeConverter.FromVtArray((VtFloatArray)jointWeights.GetAttr().Get()); int weightsElementSize = jointWeights.GetElementSize(); pxr.TfToken weightsInterpolation = jointWeights.GetInterpolation(); if (weights.Length == 0 || weightsElementSize == 0 || weights.Length % weightsElementSize != 0 || !pxr.UsdGeomPrimvar.IsValidInterpolation(weightsInterpolation)) { throw new Exception("Joints weights information are invalid or empty for: " + meshPath); } // Get and validate the local list of joints. VtTokenArray jointsAttr = new VtTokenArray(); skinningQuery.GetJointOrder(jointsAttr); // If jointsAttr wasn't define, GetJointOrder return an empty array and FromVtArray as well. string[] joints = IntrinsicTypeConverter.FromVtArray(jointsAttr); // WARNING: Do not mutate skeleton values. string[] skelJoints = skeleton.joints; if (joints == null || joints.Length == 0) { if (skelJoints == null || skelJoints.Length == 0) { throw new Exception("Joints array empty: " + meshPath); } else { joints = skelJoints; } } var mesh = smr.sharedMesh; // TODO: bind transform attribute can be animated. It's not handled yet. Matrix4x4 geomXf = UnityTypeConverter.FromMatrix(skinningQuery.GetGeomBindTransform()); // If the joints list is a different length than the bind transforms, then this is likely // a mesh using a subset of the total bones in the skeleton and the bindTransforms must be // reconstructed. var bindPoses = skeleton.bindTransforms; if (!JointsMatch(skeleton.joints, joints)) { var boneToPose = new Dictionary <string, Matrix4x4>(); bindPoses = new Matrix4x4[joints.Length]; for (int i = 0; i < skelJoints.Length; i++) { boneToPose[skelJoints[i]] = skeleton.bindTransforms[i]; } for (int i = 0; i < joints.Length; i++) { bindPoses[i] = boneToPose[joints[i]]; } } // When geomXf is identity, we can take a shortcut and just use the exact skeleton bindPoses. if (!ImporterBase.ApproximatelyEqual(geomXf, Matrix4x4.identity)) { // Note that the bind poses were transformed when the skeleton was imported, but the // geomBindTransform is per-mesh, so it must be transformed here so it is in the same space // as the bind pose. XformImporter.ImportXform(ref geomXf, options); // Make a copy only if we haven't already copied the bind poses earlier. if (bindPoses == skeleton.bindTransforms) { var newBindPoses = new Matrix4x4[skeleton.bindTransforms.Length]; Array.Copy(bindPoses, newBindPoses, bindPoses.Length); bindPoses = newBindPoses; } // Concatenate the geometry bind transform with the skeleton bind poses. for (int i = 0; i < bindPoses.Length; i++) { // The geometry transform should be applied to the points before any other transform, // hence the right hand multiply here. bindPoses[i] = bindPoses[i] * geomXf; } } mesh.bindposes = bindPoses; var bones = new Transform[joints.Length]; var sdfSkelPath = new SdfPath(skelPath); for (int i = 0; i < joints.Length; i++) { var jointPath = new SdfPath(joints[i]); if (joints[i] == "/") { jointPath = sdfSkelPath; } else if (jointPath.IsAbsolutePath()) { Debug.LogException(new Exception("Unexpected absolute joint path: " + jointPath)); jointPath = new SdfPath(joints[i].TrimStart('/')); jointPath = sdfSkelPath.AppendPath(jointPath); } else { jointPath = sdfSkelPath.AppendPath(jointPath); } var jointGo = primMap[jointPath]; if (!jointGo) { Debug.LogError("Error importing " + meshPath + " " + "Joint not found: " + joints[i]); continue; } bones[i] = jointGo.transform; } smr.bones = bones; bool isConstant = weightsInterpolation.GetString() == pxr.UsdGeomTokens.constant; // Unity 2019 supports many-bone rigs, older versions of Unity only support four bones. #if UNITY_2019 var bonesPerVertex = new NativeArray <byte>(mesh.vertexCount, Allocator.Persistent); var boneWeights1 = new NativeArray <BoneWeight1>(mesh.vertexCount * weightsElementSize, Allocator.Persistent); for (int i = 0; i < mesh.vertexCount; i++) { int unityIndex = i * weightsElementSize; int usdIndex = isConstant ? 0 : unityIndex; bonesPerVertex[i] = (byte)weightsElementSize; for (int wi = 0; wi < weightsElementSize; wi++) { var bw = boneWeights1[unityIndex + wi]; bw.boneIndex = indices[usdIndex + wi]; bw.weight = weights[usdIndex + wi]; boneWeights1[unityIndex + wi] = bw; } } // TODO: Investigate if bone weights should be normalized before this line. mesh.SetBoneWeights(bonesPerVertex, boneWeights1); bonesPerVertex.Dispose(); boneWeights1.Dispose(); #else var boneWeights = new BoneWeight[mesh.vertexCount]; for (int i = 0; i < boneWeights.Length; i++) { // When interpolation is constant, the base usdIndex should always be zero. // When non-constant, the offset is the index times the number of weights per vertex. int usdIndex = isConstant ? 0 : i * weightsElementSize; var boneWeight = boneWeights[i]; if (usdIndex >= indices.Length) { Debug.Log("UsdIndex out of bounds: " + usdIndex + " indices.Length: " + indices.Length + " boneWeights.Length: " + boneWeights.Length + " mesh: " + meshPath); } boneWeight.boneIndex0 = indices[usdIndex]; boneWeight.weight0 = weights[usdIndex]; if (indicesElementSize >= 2) { boneWeight.boneIndex1 = indices[usdIndex + 1]; boneWeight.weight1 = weights[usdIndex + 1]; } if (indicesElementSize >= 3) { boneWeight.boneIndex2 = indices[usdIndex + 2]; boneWeight.weight2 = weights[usdIndex + 2]; } if (indicesElementSize >= 4) { boneWeight.boneIndex3 = indices[usdIndex + 3]; boneWeight.weight3 = weights[usdIndex + 3]; } // If weights are less than 1, Unity will not automatically renormalize. // If weights are greater than 1, Unity will renormalize. // Only normalize when less than one to make it easier to diff bone weights which were // round-tripped and were being normalized by Unity. float sum = boneWeight.weight0 + boneWeight.weight1 + boneWeight.weight2 + boneWeight.weight3; if (sum < 1) { boneWeight.weight0 /= sum; boneWeight.weight1 /= sum; boneWeight.weight2 /= sum; boneWeight.weight3 /= sum; } boneWeights[i] = boneWeight; } mesh.boneWeights = boneWeights; #endif }