Hello everyone, I'm working on a visionOS application using RealityKit and am encountering a common coordinate system challenge when integrating 3D models created in Blender. My goal is to display and dynamically update the Transform (position, rotation, scale) of models created in Blender within RealityKit. The issue arises because Blender's default coordinate system is Z-up, and while exporting to USD/USDZ, I don't have a reliable "Y-up" export option that correctly reorients the model and its transform data for RealityKit's Y-up convention. This means I'm essentially exporting models with their "up" direction along the Z-axis. When I load these Z-up exported models into RealityKit, they are often oriented incorrectly. To then programmatically update their Transform (e.g., move them, rotate them based on game logic, or apply physics), I need to ensure that the Transform values I set align with RealityKit's Y-up system, even though the original model data was authored in a Z-up context. My questions are: What is the recommended transformation process (e.g., using simd_quatf or simd_float4x4) to convert a Transform that was conceptually defined in a Z-up coordinate system to RealityKit's Y-up coordinate system? Specifically, when I have a Transform (or its translation, rotation, scale components) from a Z-up context, how should I apply this to a RealityKit Entity so it appears and behaves correctly in a Y-up world? Are there any existing convenience APIs or helper functions within RealityKit, simd, or other Apple frameworks that simplify this Z-up to Y-up Transform conversion process? Or is a manual application of a transformation quaternion (e.g., simd_quatf(angle: -.pi / 2, axis: [1, 0, 0])) the standard approach? Any guidance, code examples, or best practices from those who have faced similar challenges would be greatly appreciated! Thank you.

Hello RealityKit developers, I'm currently working on physics simulations in my visionOS app and am trying to adapt the concepts from the official sample Simulating physics joints in your RealityKit app. In the sample, a sphere is connected to the ceiling using a PhysicsRevoluteJoint to create a hinge-like simulation. I've successfully modified this setup to use a PhysicsSphericalJoint instead. The basic replacement works as expected: pin1 (attached to the sphere) rotates freely around pin0 (attached to the ceiling), much like a ball-and-socket joint should, removing all translational degrees of freedom. My challenge lies with the PhysicsSphericalJoint's angularLimitInYZ property. The documentation mentions that this property allows limiting the rotation around the Y and Z axes, defining an "elliptical cone shape around the x-axis of pin0." However, I'm struggling to understand how to specify these values to achieve a desired rotational limit. If I have a sphere that is currently capable of rotating 360 degrees around pin0 (like a free-spinning ball on a string), how would I use angularLimitInYZ to restrict its rotation to a certain height or angular range, preventing it from completing a full circle? Specifically, I'm trying to achieve a "swing" like behavior where the sphere oscillates back and forth but cannot rotate completely overhead or underfoot. What values or approach should I use for the angularLimitInYZ tuple to define such a restricted pendulum-like motion? Any insights, code examples, or explanations on how to properly configure angularLimitInYZ for this kind of behavior would be incredibly helpful! The following code is modified from the sample. extension MainView { func addPinsTo(ballEntity: Entity, attachmentEntity: Entity) throws { let hingeOrientation = simd_quatf(from: [1, 0, 0], to: [0, 0, 1]) let attachmentPin = attachmentEntity.pins.set( named: "attachment_hinge", position: .zero, orientation: hingeOrientation ) let relativeJointLocation = attachmentEntity.position( relativeTo: ballEntity ) let ballPin = ballEntity.pins.set( named: "ball_hinge", position: relativeJointLocation, orientation: hingeOrientation ) // Create a PhysicsSphericalJoint between the two pins. let revoluteJoint = PhysicsSphericalJoint(pin0: attachmentPin, pin1: ballPin) try revoluteJoint.addToSimulation() } } The following image is a screenshot of the operation when changing to PhysicsSphericalJoint. Thank you in advance for your assistance.

TL;DR: RealityKit and Reality Composer Pro aren't forward or backward compatible with each other, and the resulting error message is terse and unhelpful. (FB14828873) So far, I've been sticking with Xcode 16.4 for development and only using Xcode 26.0 beta experimentally. Yesterday, I used xcode-select to switch to Xcode 26.0 beta 3 to test it, but I forgot to switch back. Consequently, this morning I unintentionally used the future Reality Composer Pro (the version included with Xcode 26) to make a small change to a USD file. Now I realize that if I'm unlucky, it's possible Reality Composer Pro may have silently introduced a small change into the USD file that may make RealityKit fail to read the file on iOS 18 and visionOS 2, which in the past has resulted in hours of debugging to track down the source of the failure, often a single line in the USD file that RealityKit can't communicate to me other than with the error "the operation couldn't be completed". As an analogy, this situation is as if, during regular development (not involving Reality Composer Pro), Xcode didn't warn you about specific API version conflicts, but instead failed with a generic error message, without highlighting the line in your Swift file that was the source of the error.

Description: In the official visionOS 26 Hover Effect sample code project , I encountered an issue where the event.trackingAreaIdentifier returned by onSpatialEvent does not reset as expected. Steps to Reproduce: Select an object with trackingAreaID = 6 in the sample app. Look at a blank space (outside any tracking area) and perform a pinch gesture . Expected Behavior: The event.trackingAreaIdentifier should return 0 when interacting with a non-tracking area. Actual Behavior: The event.trackingAreaIdentifier still returns 6, even after restarting the app or killing the process. This persists regardless of where the pinch gesture is performed

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]

I am an AR developer working on Apple Silicon Macs. Currently, Reality Composer Pro does not allow exporting .reality files, and Reality Composer (classic) is not available for Apple Silicon. This creates a gap in the workflow for ARKit/RealityKit developers who need interactive .reality files for use in Xcode projects. Having the ability to export .reality files directly from Reality Composer Pro on Mac would greatly streamline development and enable a fully native workflow on modern Macs. Alternatively, bringing Reality Composer (classic) to Apple Silicon would also resolve this issue. I have submitted this as a feature request via Feedback Assistant (FB17900386). I encourage others with similar needs to reply or submit feedback as well. Thank you!

This week, I developed a small multiplatform RealityKit project. I also created a demo scene in Reality Composer Pro. Afterward, I imported the local package into the project. Running the project on macOS works perfectly. However, when I tried to run it on my iPhone, I encountered a permission error indicating that it couldn’t read the package. This seems unusual to me because I assumed that the dependency is bundled into the binary file. In an attempt to resolve the issue, I pushed the RCP package to GitHub, hoping it would work. Fortunately, everything compiles successfully now, but the loading time is significantly long, and the animations don’t play on tap gestures. Could someone please help me identify the root cause of this problem?

I've loaded a ShaderGraphMaterial from a RealityKit content bundle and I'm attempting to access the initial values of its parameters using getParameter(handle:), but this method appears to always return nil: let shaderGraphMaterial = try await ShaderGraphMaterial(named: "MyMaterial", from: "MyFile") let namedParameterValue = shaderGraphMaterial.getParameter(name: "myParameter") // This prints the value of the `myParameter` parameter, as expected. print("namedParameterValue = \(namedParameterValue)") let handle = ShaderGraphMaterial.parameterHandle(name: "myParameter") let handleParameterValue = shaderGraphMaterial.getParameter(handle: handle) // Expected behavior: prints the value of the `myParameter` parameter, as above. // Observed behavior: prints `nil`. print("handleParameterValue = \(handleParameterValue)") Is this expected behavior? Based on the documentation at https://developer.apple.com/documentation/realitykit/shadergraphmaterial/getparameter(handle:) I'd expect getParameter(handle:) to return the value of the parameter, just as getParameter(name:) does. I've tested this on iOS 18.5 and iOS 26.0 beta 2. Assuming this getParameter(handle:) works as designed, is the following ShaderGraphMaterial extension an appropriate workaround, or can you recommend a better approach? Thank you. public extension ShaderGraphMaterial { /// Reassigns the values of all named material parameters using the handle-based API. /// /// This works around an issue where, at least as of RealityKit 26.0 beta 2 and /// earlier, `getParameter(handle:)` will always return `nil` when used to read the /// initial value of a shader graph material parameter read using /// `ShaderGraphMaterial(named:from:in:)`, whereas `getParameter(name:)` will work /// as expected. private mutating func copyNamedParametersToHandles() { for parameterName in self.parameterNames { if let value = self.getParameter(name: parameterName) { let handle = ShaderGraphMaterial.parameterHandle(name: parameterName) do { try self.setParameter(handle: handle, value: value) } catch { assertionFailure("Cannot set parameter value") } } } } }

Any way to extend the video recording time in Reality Composer Pro from 3:00 to any longer value, such as editing preferences in Terminal or other workaround? Is there any way to use the strap and a USB-C cable as a live video stream input source that would mirror to Quicktime or some other video capture tool? I am assuming there is no online documentation or user manual for the strap, but please correct me if I'm wrong. Thank you.

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 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!