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 } }

It is gone from where I used to find it on Apple’s web site. Is it deprecated or no longer available?

So I am exporting a .usdc file from blender that already has some morph animations. The animations play well in blender but when I export I cannot seem to play them in RealityKit or RCP. Entity.availableAnimations is an empty array. Not of the child objects in the entity hierarchy has an animation library component with it. Maybe I am exporting it wrong but I tried multiple combinations but doesn't seem to work. Here are my export settings in blender The original file I purchased is an FBX file that has the animation but when I try to directly get it in RealityConverter it doesn't seem to play animations.

I want to implement the functions in this video, how should I set the window

Hello everyone, I've been trying for a few weeks now to convert a sequential series of meshes into a stop-motion animation in USDZ format. In Unreal Engine, I’ve already figured out how to transform the sequential series of individual meshes into a smooth animation using the node system and arrays. Unfortunately, the node system cannot be exported as a usdz animation logic in either Unreal or Blender. Because of this, I have tried several other methods to incorporate the animation logic. Here’s what I’ve tried so far: I attempted to create the animation in Blender with Render-/Viewports and mapping it to keyframes. However, in my experience, Viewports are not supported in the conversion. I tried aligning the vertices of individual objects and merging the frames using the Shrinkwrap modifier in Blender, then setting up a morph animation with keyframes. However, because the individual meshes are too different, this results in artifacts, and manually editing each mesh is too difficult for me to handle. I placed all individual meshes at the same position and animated them sequentially by scaling them from 0 to 100 in keyframes (Frame 1 is visible for 10 frames, then scales down at frame 11, while Frame 2 becomes visible at frame 11, and so on). I also adjusted the keyframes so that the scaling happens in a "constant" manner rather than the default Bezier or linear interpolation. I then converted this animation to .abc, and the result initially looked good. However, some information is lost when converting it with OpenUSD. The animation does not maintain its intended jump-like behavior in USDZ format, and instead, the scaling of individual files is visible in the animation. I tried using a Blender add-on (StepMotion), which allows the animation to be exported as .abc, but it can only be read in Blender or Unreal. Even in the preview, the animation is not displayed correctly, so converting the animation logic does not work either. 
Unfortunately, I have no alternative way to create the animation, as the individual frames have been provided to me as meshes. So far, I haven’t found a way to implement this successfully. I would be very grateful for any tips or ideas, as I am running out of options on how to make this work. Thanks in advance!

When importing FBX animations (generated by Cinema 4d or Blender) the models come in very far way and cannot resize or zoomed in. I have tried every setting from both programs to no avail. Is there a secret to providing the right export options? When importing without animations/and rigging the model imports fine and correct size. But once motion is included, something is awry. I also tried changing base units in Converter, but did not work. I have attache my model heirarchy in C4D as well as the imported result. It appears the animation is imported, as I can see it move, but can barely see it :)

Hi everyone, I’m experiencing a critical issue with USDZ files created in Reality Composer on an iPad 9th Generation (iPadOS 18.3). The files work perfectly on iPads from the 10th Generation onwards and on iPad Pros. However, on older devices like the iPad 9th Generation and older iPhones, QuickLook (file preview) crashes when opening them. This is a major issue because these USDZ files are part of an exhibition where artworks are extended with AR elements via a web page. If some visitors cannot view the 3D content, it significantly impacts the experience. What’s puzzling is that two years ago, we exported USDZ files from Reality Composer, made them available via a website, and they worked flawlessly on all devices, including older iPads and iPhones. Now, with the latest iPadOS, they consistently crash on older devices. Has anyone encountered a similar issue? Are there known limitations with QuickLook on older devices, or is there a way to optimize the USDZ files to prevent crashes? Could this be related to changes in iPadOS or RealityKit? Any advice or workaround would be greatly appreciated! Thanks in advance!

I have created a simple scene in reality composer (composer not composer pro). It contains just a cube and text item. I convert this to usdz file and load it into a Arkit swift app. Since ios 18/xcode 16 - the "text" element is not displayed at all. The cube is displayed, anchors correctly and can be moved etc.... The output from usdchecker ➜ Desktop usdchecker GKTUHR1.6.3.usdz -v --arkit Opening GKTUHR1.6.3.usdz Checking layer <GKTUHR1.6.3.usdz>. Checking package <GKTUHR1.6.3.usdz> Checking prim </Root>. Checking prim </Root/Scenes>. Checking prim </Root/Scenes/Scene>. Checking prim </Root/Scenes/Scene/Gravity>. Checking prim </Root/Scenes/Scene/sceneGroundPlane>. Checking prim </Root/Scenes/Scene/sceneGroundPlane/physicsMaterial>. Checking prim </Root/Scenes/Scene/Children>. Checking prim </Root/Scenes/Scene/Children/hello>. Checking prim </Root/Scenes/Scene/Children/hello/Generated>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>. Checking shader </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>. Checking prim </Root/Scenes/Scene/Children/hello/Children>. Checking prim </Root/Scenes/Scene/Children/Box>. Checking prim </Root/Scenes/Scene/Children/Box/Generated>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Mesh0>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>. Checking shader </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>. Checking prim </Root/Scenes/Scene/Children/Box/Children>. Checking prim </Root/Scenes/Scene/Children/Box/PhysicsMaterial_Box>. Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/sceneGroundPlane>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/hello/Generated/Text>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>. (fails 'MaterialBindingAPIAppliedChecker') Failed!

Hello Dev Community, I've been thinking over Apple's preference for USDZ for AR and 3D content, especially when there's the widely used GLTF. I'm keen to discuss and hear your insights on this choice. USDZ, backed by Apple, has seen a surge in the AR community. It boasts advantages like compactness, animation support, and ARKit compatibility. In contrast, GLTF too is a popular format with its own merits, like being an open standard and offering flexibility. Here are some of my questions toward the use of USDZ: Why did Apple choose USDZ over other 3D file formats like GLTF? What benefits does USDZ bring to Apple's AR and 3D content ecosystem? Are there any limitations of USDZ compared to other file formats? Could factors like compatibility, security, or integration ease have influenced Apple's decision? I would love to hear your thoughts on this. Feel free to share any experiences with USDZ or other 3D file formats within Apple's ecosystem!