Goal: To render in an apple vision pro app, the solid-mechanics 3D simulation results coming form an FEA code. Starting point: I have surface vtks with deformations on each node. Each time step has a a mesh with the nodal coordinates. This is straighforward translatable to a usd MeshSequence. Unfortunately, the results cannot be simplified to a scaling o linear transformation as you would do with other game-oriented animations. Tools: Right now, I am using Xcode and reality composer pro (RCP) to build the scenes. Technical limitations: I am aware that RCP can do animations with BlendMesh and skeletons and that MeshSequence is not a problem. Progress: Coverting to the sequence of vtk meshes to a usd MeshSequence is straighforward. This animates correctly in Preview and Blender (see screenshot). I managed to convert from MeshSequence to multiple keys and BlendMesh. This also animates correctly in Blender and preview. Unfortunately, the BlendMesh of multiple blended meshes shows a zero animation time in RCP (see screenshot below) Also, see below usda file scheme for the animation. Of course I am not showing full vectors such as faceVertexCounts, faceVertexIndex, normals. Question: what is the right set up to create a BlendMesh animation that RCP will correctly import and animate, form a set of Meshes or multiple key shapes? Blender animation Time zero RCP "animations" #usda 1.0 ( defaultPrim = "BlendMeshRoot" doc = "Blender v4.5.3 LTS" endTimeCode = 48 framesPerSecond = 24 metersPerUnit = 1 startTimeCode = 0 timeCodesPerSecond = 24 upAxis = "Z" ) def Xform "BlendMeshRoot" ( customData = { dictionary Blender = { bool generated = 1 } } ) { def SkelRoot "Mesh" { custom string userProperties:blender:object_name = "Mesh" float3 xformOp:rotateXYZ = (89.99999, -0, 0) float3 xformOp:scale = (0.009999999, 0.01, 0.01) double3 xformOp:translate = (0, 0, 0) uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:rotateXYZ", "xformOp:scale"] def Mesh "Mesh" ( active = true prepend apiSchemas = ["MaterialBindingAPI", "SkelBindingAPI"] ) { uniform bool doubleSided = 1 float3[] extent = [(25.091871, -34.121277, -13.298501), (299.94482, 245.10088, 202.35126)] int[] faceVertexCounts = [3, 3, ... int[] faceVertexIndices = [0, 10293, ... rel material:binding = </BlendMeshRoot/_materials/MeshSequence_Default> normal3f[] normals = [(-0.3632836, -0.9102419, -0.19870725), .... point3f[] points = [(244.41148, 155.42062, 70.454926),..... float3[] primvars:node_displacement = [(93.54703, 110.9341, 48.37992).... float3[] primvars:Normals = [(-0.0050530406, -0.9910114, -0.13368203),... int[] primvars:skel:jointIndices = [0, 0, 0, 0, 0 ... float[] primvars:skel:jointWeights = [1, 1, 1, 1, 1... uniform token[] skel:blendShapes = ["frame_0000", "frame_0001", "frame_0002", "frame_0003", "frame_0004", "frame_0005"] rel skel:blendShapeTargets = [ </BlendMeshRoot/Mesh/Mesh/frame_0000>, ....... </BlendMeshRoot/Mesh/Mesh/frame_0005>, ] prepend rel skel:skeleton = </BlendMeshRoot/Mesh/Skel> uniform token subdivisionScheme = "none" custom string userProperties:blender:data_name = "Mesh" custom float userProperties:originalTime float userProperties:originalTime.timeSamples = { 0: 0, } def BlendShape "frame_0000" { uniform vector3f[] offsets = [(0, 0, 0), (0, 0, 0),..... uniform int[] pointIndices = [0, 1, 2, ..... } ..... ..... #### BlendShape frame to 0005 ..... def Skeleton "Skel" ( prepend apiSchemas = ["SkelBindingAPI"] ) { uniform matrix4d[] bindTransforms = [( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )] uniform token[] joints = ["joint1"] uniform matrix4d[] restTransforms = [( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )] prepend rel skel:animationSource = </BlendMeshRoot/Mesh/Skel/Anim> def SkelAnimation "Anim" { uniform token[] blendShapes = ["frame_0000", "frame_0001", "frame_0002", "frame_0003", "frame_0004", "frame_0005"] float[] blendShapeWeights.timeSamples = { 0: [1, 0, 0, 0, 0, 0], 1: [0.9697085, 0.03029152, 0, 0, 0, 0], 2: [0.88787615, 0.11212383, 0, 0, 0, 0], ..... 46: [0, 0, 0, 0, 0.11212379, 0.8878762], 47: [0, 0, 0, 0, 0.030291557, 0.96970844], 48: [0, 0, 0, 0, 0, 1], } } } } def Scope "_materials" { def Material "MeshSequence_Default" { token outputs:surface.connect = </BlendMeshRoot/_materials/MeshSequence_Default/Principled_BSDF.outputs:surface> custom string userProperties:blender:data_name = "MeshSequence_Default" def Shader "Principled_BSDF" { uniform token info:id = "UsdPreviewSurface" float inputs:clearcoat = 0 float inputs:clearcoatRoughness = 0.03 color3f inputs:diffuseColor = (0.8, 0.4, 0.3) float inputs:ior = 1.5 float inputs:metallic = 0 float inputs:opacity = 1 float inputs:roughness = 0.5 float inputs:specular = 0.2 token outputs:surface } } } def Scope "AnimationClips" { custom rel animations = </BlendMeshRoot/Mesh/Skel/Anim> } def RealityKitComponent "AnimationLibrary" { custom rel animations = </BlendMeshRoot/Mesh/Skel/Anim> custom token info:id = "RealityKit.AnimationLibrary" custom double realitykit:approximateDuration = 2 custom double[] realitykit:clipDurations = [2] custom string[] realitykit:clipNames = ["Anim"] custom rel realitykit:clipTargets = </BlendMeshRoot/Mesh/Skel/Anim> custom double realitykit:frameRate = 24 custom bool realitykit:isAnimationLibrary = 1 } }