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!

I use SCNScene.write To file ".usdz", then open the ".usdz" by SCNScene.url , all Nodes color fades. Export and load only once. The fading is not obvious. Return and repeat 4 or 5 times. It is obvious that the color is inconsistent with the original color and has become much lighter.

In the Creating A 3D Application With Hydra Rendering tutorial on the Apple Developer website, on the last step where I execute this command: cmake -S ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ -B ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ I keep getting an error: CMake Error at CMakeLists.txt:5 (include): include could not find requested file: /Users/macuser/USDInstall/bin/pxrConfig.cmake I've tried to follow the instructions as mentioned in the README.md file included in the project files at least 5 times as well as moving the pxrConfig.cmake file around and copying it in different folders, then executed the command and was still unsuccessful into generating the proper file expected to compile and render the HydraPlayer renderer. How do I get cmake to generate the Xcode file to create the HydraPlayer renderer?

Hello! I’m familiar with the discussion on “Sending messages to the scene”, and I’ve successfully used that code. However, I have several instances of the same model in my scene. Is it possible to make only one specific model respond to a notification? For example, can I pass something like RealityKit.NotificationTrigger.SourceEntity in userInfo or use another method to target just one instance?

ar quicklook suddenly is grayed out on iphone 15 pro, I bought the phone new recently ot was working great, 2 days ago updated to ios 18.1.4, ar mode kept opening but i started getting a move iphone over surface message and the object wouldn’t detect surfaces correctly, updated to ios 18.5, now when i open quicklook modesl ar is completely greyed out, can someone help me fix or detect the issue thank you

Hello everyone, I'm a new developer and I'm still learning the foundations of Swift and SwiftUI while building my first app. Today I wanted to ask you how to implement AR Quixck Views inside my app. I wanna be able to dynamically preview AR objects in a dedicated view, however, I don't seem to have understood where and how to locate AR objects inside my project. I tried including them in the Assets folder of the project, or in the Recources folder, or within the main folder of my project alongside the MyAppApp.swift file. None of the methods I used seemed have worked in that none of the objects was ever located. I made sure to specify the path to the files every time, but somehow the location isn't recognized. I also tried giving no path so that the app would search for the files in their default location (which I apparently haven't grasped yet), but still my attempt failed. I don't have the code sample on me at the moment, but I will write a followup comment on this post to show you what I wrote in case anyone was interested in debugging my code. Meanwhile, if anyone would be so kind to point me at the support article or to comment below the sample code they used in their app, I would very much appreciate it, so that I can start debugging. Thank you for reading this, I appreciate you.

I need a MeshResource from ModelEntity to generate a box collider, but ModelEntity fails to load USDZ files from the Reality Composer Pro (RCP) bundle. This code works for loading an Entity: // Successfully loads as generic Entity previewEntity = try await Entity(named: fileName, in: realityKitContentBundle) But this fails when trying to load as ModelEntity: // Fails to load as ModelEntity modelEntity = try await ModelEntity(named: fileName, in: realityKitContentBundle) I found this thread mentioning: "You'll likely go from USDZ to Entity which contains a MeshResource when you load/init the USDZ file." But it doesn't explain ​how to actually extract the MeshResource. Could anyone advise: How to properly load USDZ files as ModelEntity from RCP bundles? How to extract MeshResource from a successfully loaded Entity? Alternative approaches to generate box colliders if direct extraction isn't possible? Sample code for extraction or workarounds would be greatly appreciated!

Is there any limitation in Vision Pro when loading scenes with large-scale models? ​Test Case: Asset: Composite USDA file containing ​10 individual models​ (total triangles count: ~4.2M) Simulator: Loads and renders correctly Real Device: Loads asset successfully but ​ failure during rendering phase: Environment abruptly dims System spontaneously reboots How can we resolve this issue? Below are excerpted logs preceding the crash: <<<< FigAudioSession(AV) >>>> audioSessionAVAudioSession_CopyMXSessionProperty signalled err=-19224 (kFigAudioSessionError_UnsupportedOperation) (getMXSessionProperty unsupported) at FigAudioSession_AVAudioSession.m:606 Attempted to add ornament: <MRUIPlatterOrnament: 0x10a658f00; _isInternal: YES; _displaceWindowChrome: NO; _canCaptureUI: NO; _isBeingRemoved: NO; contentAnchorPoint3D: "{0.5, 0.5, 0}"; position: <MRUIPlatterOrnamentRelativePosition: 0x105b68e70; anchorPoint: {0.5, 0.5, 1}>; rotation: "{{0, 0, 0}, 0}"; opacity: 1.000000; canFollowUser: YES; effectiveOffset: "{0, 0, 0}"; presentingViewController: 0x0; billboardingBehavior: 0x0; scalingBehavior: 0x0; relativeToParent: NO; nonHeritableDepthDisplacement: 0.000000; order: 0.000000; _window._determinedSize: {0, 0}; _window: (null)> to nil or non-supporting UIScene: <UIWindowScene: 0x10a8a0000; role: UISceneSessionRoleImmersiveSpaceApplication; persistentIdentifier: test.test:SFBSystemService-BA3A21A3-D1AB-42E2-8AF0-AE0AB83BE528; activationState: UISceneActivationStateUnattached>. No action taken. Failed to set dependencies on asset 2823930584475958382 because NetworkAssetManager does not have an asset entity for that id. apply fence tx failed (client=0x98490e18) [0x10000003 (ipc/send) invalid destination port] Failed to commit transaction (client=0xa86516e2) [0x10000003 (ipc/send) invalid destination port]

Hi all, I've encountered a potential issue with how the winding order of geometry is handled when their transformations involve negative scaling. I created a simple test asset, a single triangle, to demonstrate this. The triangle's vertices are defined in a counter-clockwise ("right-handed") winding order, and its transform has a negative scale on the X-axis. According to the OpenUSD specification, this negative determinant in the transformation matrix should effectively reverse the winding order of the geometry: However, any given gprim's local-to-world transformation can flip its effective orientation, when it contains an odd number of negative scales. This condition can be reliably detected using the (Jacobian) determinant of the local-to-world transform: if the determinant is less than zero, then the gprim's orientation has been flipped, and therefore one must apply the opposite handedness rule when computing its surface normals (or just flip the computed normals) for the purposes of hidden surface detection and lighting calculations. When I view the asset in tools like Blender or Preview on macOS, it behaves as expected. The triangle's effective orientation is flipped to CW. However, when the same asset is viewed in Reality Composer Pro or with QuickLook on iOS, its effective orientation remains CCW. In other words, the triangle faces the opposite direction. My questions for the community and Apple are: Is this behavior in RealityKit a known issue? If this is a known issue, is there official guidance for DCC tools on how to export USDZ assets to ensure they appear correctly in the Apple ecosystem? Any insights or recommendations would be greatly appreciated.

Most models are only available as glb or fbx, so I usually reexport them into usdz using Blender. When I import them into Reality Composer Pro, Mesh, Textures etc look great, but in the Animation Library subsection all I can see is one default subtree animation. In Blender I can see all available animations and play them individually. The default subtree animation just plays the default idle animation. In fact when I open the nonlinear animation view in Blender and select a different animation as the default animation, the exported usdz shows the newly selected animation as default subtree animation. I can see in the Apple sample apps models can have multiple animations in their Animation Library. I'm using the latest Blender 4.5 and the usdz exporter should be working properly?

Hi, I'm developing a prototype VisionOS game. How to access the bones or joints information when exporting a USD file from Blender to RCP? The animation in RCP works fine and the joints' information is correctly embedded in the USDA file (with usdchecker). However, RCP does not read it in USDA, USDC or USDZ. It should be possible based on Apple WWDC24 (Compose Interactive 3D content in RCP). I want to attach and detach an entity to a particular bone in certain moments. So I need the bones' data. They are standard mixamo animations. My mesh is a single unified mesh. Using Blender 4.4