Discuss Spatial Computing on Apple Platforms.

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Request for gaze data in fully immersive Metal apps
Hi, We are trying to port our Unity app from other XR devices to Vision Pro. Thus it's way easier for us to use the Metal rendering layer, fully immersive. And to stay true to the platform, we want to keep the gaze/pinch interaction system. But we just noticed that, unlike Polyspatial XR apps, VisionOS XR in Metal does not provide gaze info unless the user is actively pinching... Which forbids any attempt to give visual feedback on what they are looking at (buttons, etc). Is this planned in Apple's roadmap ? Thanks
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Feb ’25
Digital Crown press when both immersive space and additional windows are presented
I have been experimenting with the Hello World sample app from https://developer.apple.com/documentation/visionos/world and I came across behavior that appears inconsistent with user-facing documentation describing the device controls at https://support.apple.com/en-gb/guide/apple-vision-pro/tan1e2a29e00/visionos I tried pressing simulator's "Home" button while "Objects in Orbit" immersive space was presented alongside with the main application window. According to user documentation, pressing Digital Crown should take the user directly to Home View. In my test a single press only dismissed the immersive space, I needed another press to "exit" the app and go to Home View. Is this behavior expected? I am assuming that "Home" button in the simulator behaves as if the user pressed Digital Crown on the device, I don't have access to the actual hardware.
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Apr ’25
Alternatives to SceneView
Hey there, since SceneView has been marked as „deprecated“ for SwiftUI, I‘m wondering which alternatives should be considered for the following situation: I have a SwiftUI app (for iOS and iPadOS) where users can view (with rotate, scale, move gestures) 3D models (USDZ) in a scene. The models will be downloaded from web backend and called via local URL paths. What I tested: I‘ve tried ARView in .nonAR mode, RealityView, however I didn‘t get the expected response -> User can rotate, scale the 3D models in a virtual space. ARView in nonAR mode still shows the object like in normal AR mode without camera stream. I tried to add Gestures to the RealityView on iOS - loading USDZ 3D models worked but the gestures didn’t). Model3D is only available for visionOS (that would be amazing to have it for iOS) I also checked QuickLook Preview however it works pretty strange via Filepicker etc, which is not the way how the user should load the 3D models in my app. Maybe I missed something, I couldn’t find anything which can help me. I‘m pretty much stucked adopting the latest and greatest frameworks/APIs in my App and taking the next steps porting my app to visionOS. Long story short 😃: Does someone have an idea what is the alternative to SceneView for USDZ 3D models? I appreciate your support!! Thanks in advance!
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Jul ’25
RotateGesture3D auto constrained to axis
Hi, On visionOS to manage entity rotation we can rely on RotateGesture3D. We can even with the constrainedToAxis parameter authorize only rotation on an x, y or z axis or even make combinations. What I want to know is if it is possible to constrain the rotation on axis automatically. Let me explain, the functionality that I would like to implement is to constrain the rotation on an axis only once the user has started his gesture. The initial gesture the user makes should let us know which axis they want to rotate on. This would be equivalent to activating a constraint automatically on one of the axes, as if we were defining the gesture on one of the axes. RotateGesture3D(constrainedToAxis: .x) RotateGesture3D(constrainedToAxis: .y) RotateGesture3D(constrainedToAxis: .z) Is it possible to do this? If so, what would be the best way to do it? A code example would be greatly appreciated. Regards Tof
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Feb ’25
Metal (Compositor Services) or RealityKit on visionOS
I am develop visionOS app. I am now very interested in Metal and Compositor Services, but I have not explored them in depth. I know that Metal has a higher degree of control freedom. I am wondering if using Compositor Services will have fewer functions than RealityKit in AR technology (such as scene reconstruction and understanding, hover effect, etc.).
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Jun ’25
How to play blend shape animations or morph animations exported from blender in Vision Pro apps using Reality Kit
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.
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Jun ’25
Background Assets in VisionOS
Hi, I'm working on a VisionOS app and would like to integrate Background Assets to download large files after the app is installed. I'm wondering what would happen if the user takes off the headset while a background asset is being downloaded. Would it continue downloading or would the download be stopped/paused? I was looking for a way to download large assets while the user is not wearing the Vision Pro, is there any other alternative? Thanks in advance.
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Jun ’25
openImmersiveSpace works as expected but never returns Result
As in the title: openImmersiveSpace works as expected. The ImmersiveSpace in the ID opens normally but the function never resolves a Result. Here is a workaround I used to make user it was on the UI thread and scenePhase was active: ` @MainActor func openSpaceWithStateCheck() async { if scenePhase == .active { Task { switch await openImmersiveSpace(id: "RoomCaptureInteraction") { case .opened: isCapturingImagery = true break case .error: print("!! An error occurred when trying to open the immersive space captureRoomImagery") case .userCancelled: print("!! The user declined opening immersive space captureRoomImagery") @unknown default: print("!! unknown default result of opening space") break } } } else { print("Scene not active, deferring immersive space opening") } } I'm on visionOS 2.4 and SDK 2.2. I have tried uninstalling the app and rebuilding. Tried simply opening an empty ImmersiveSpace. The consistency of the ImmersiveSpace opening at least means I can work around it. Even dismissImmersiveSpace works normally and closes the immersive space. But a workaround seems hamfisted.
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Mar ’25
Creating spatial video with one camera
Hello everyone I would like to create my own spatial video on my Apple Vision Pro. According to all the documentation from Apple, this requires two camera angles that enhance the spatial perception. I have purchased the Enterprise license with main camera access for this purpose. However, this only gives me access to the left main camera of the glasses. Is there a way to access the right camera as well? Or is the one camera image enough to create a spatial video by splitting the image, for example? I am open to any help and ideas. My goal is to create the video with the cameras on the glasses, not externally.
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Jun ’25
Reading scenePhase from custom Scene
Hi, I've encountered a thread where an Apple engineer points out that there are 2 possible ways to anchor scenePhase, either App or View implementation: https://developer.apple.com/forums/thread/757429 This thread also links to documentation which states If you read the phase from within a custom Scene instance, the value similarly reflects an aggregation of all the scenes that make up the custom scene: This doesn't seem to be the case on visionOS 2, I tried the following code starting from an empty app template: import SwiftUI @main struct SceneTestApp: App { var body: some Scene { MyScene() WindowGroup(id: "extra") { Text("Extra window") } } } struct MyScene: Scene { @Environment(\.scenePhase) private var scenePhase @Environment(\.openWindow) private var openWindow var body: some Scene { WindowGroup { ContentView() .onAppear { openWindow(id: "extra") } } .onChange(of: scenePhase) { oldValue, newValue in print("scenePhase changed") } } } The result was that I didn't get onChange callback if I only closed the extra window, the callback only came after I closed both windows and the whole app was suspended. Is this expected behavior?
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Feb ’25
RealityKit entity.write(to:) generates fatal protection error
My app for framing and arranging pictures from Photos on visionOS allows users to write the arrangements they create to .reality files using RealityKit entity.write(to:) that they then display to customers on their websites. This works perfectly on visionOS 2, but fails with a fatal protection error on visionOS 26 beta 1 and beta 2 when write(to:) attempts to write to its internal cache: 2025-06-29 14:03:04.688 Failed to write reality file Error Domain=RERealityFileWriterErrorDomain Code=10 "Could not create parent folders for file path /var/mobile/Containers/Data/Application/81E1DDC4-331F-425D-919B-3AB87390479A/Library/Caches/com.GeorgePurvis.Photography.FrameItVision/RealityFileBundleZippingTmp_A049685F-C9B2-479B-890D-CF43D13B60E9/41453BC9-26CB-46C5-ADBE-C0A50253EC27." UserInfo={NSLocalizedDescription=Could not create parent folders for file path /var/mobile/Containers/Data/Application/81E1DDC4-331F-425D-919B-3AB87390479A/Library/Caches/com.GeorgePurvis.Photography.FrameItVision/RealityFileBundleZippingTmp_A049685F-C9B2-479B-890D-CF43D13B60E9/41453BC9-26CB-46C5-ADBE-C0A50253EC27.} Has anyone else encountered this problem? Do you have a workaround? Have you filed a feedback? ChatGPT analysis of the error and my code reports: Why there is no workaround • entity.write(to:) is a black box — you cannot override where it builds its staging bundle • it always tries to create those random folders itself • you cannot supply a parent or working directory to RealityFileWriter • so if the system fails to create that folder, you cannot patch it 👉 This is why you see a fatal error with no recovery. See also feedbacks: FB18494954, FB18036627, FB18063766
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500
Jul ’25
Imitating a grip on an object
I'm playing about with the hand tracking systems in reality kit / Vision Pro I thought it would be interesting if I could attach a virtual object to a hand when the hand is gripping (thought it would be fun to attach a basic cylinder to mimic a wand from Harry Potter) I'm able to detect when the user is gripping but having trouble placing an object as though it's within the hand. The simplest version of this is using an AnchorEntity pointing to the user's palm which kind of works, but quickly breaks the illusion when you rotate the wrist or hand. It seems as though I will have to roll my own anchor entity using the various points of the user's hand and I thought calculating some median point between the thumb and little finger tips would be a good start but it's proven a little difficult as we need both rotation and position. I'm already out of my depth with reality kit and matrices (and thanks to ChatGPT) I have some code, but as soon as I apply the position manually (as opposed to a hand anchor entity) it fails to render on the user's hand. It feels like this should already have been something someone has looked in to, any ideas on what might be the issue here? Note: HandTrackingSystem.handTracking is a HandTrackingProvider() guard let anchors = HandTrackingSystem.handTracking.latestAnchors.leftHand else { return } if let thumb = anchors.handSkeleton?.joint(.thumbTip), let little = anchors.handSkeleton?.joint(.littleFingerTip) { let thumbPos = simd_make_float3(thumb.anchorFromJointTransform.columns.3) let littlePos = simd_make_float3(little.anchorFromJointTransform.columns.3) let midPos = (thumbPos + littlePos) / 2 let direction = normalize(littlePos - thumbPos) let rotation = simd_quatf(from: [0, 1, 0], to: direction) wandEntity.transform.translation = midPos wandEntity.transform.rotation = rotation content.add(wandEntity) }
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Jul ’25
VisionOS Beta 3 spatial sculpting apple sample crash
Hello since updating to beta 3 the sculpting sample app doesn't work it crashes on running. seems to be something in AnchorEntity or AccessoryAnchoringSource Referenced from: <00B81486-1A74-30A0-B75B-4B39E3AF57DF> /private/var/containers/Bundle/Application/3D2EBF59-19F0-4BF4-8567-6962AA36A2C6/delete.app/delete.debug.dylib Expected in: <BAA9B221-78A1-3B99-AA2F-B8DFCD179FC7> /System/Library/Frameworks/RealityFoundation.framework/RealityFoundation
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Jul ’25
Unexpected Behavior in Entity Movement System When Using AVAudioPlayer in visionOS Development
I am currently developing an app for visionOS and have encountered an issue involving a component and system that moves an entity up and down within a specific Y-axis range. The system works as expected until I introduce sound playback using AVAudioPlayer. Whenever I use AVAudioPlayer to play sound, the entity exhibits unexpected behaviors, such as freezing or becoming unresponsive. The freezing of the entity's movement is particularly noticeable when playing the audio for the first time. After that, it becomes less noticeable, but you can still feel it, especially when the audio is played in quick succession. Also, the issue is more noticable on real device than the simulator // // IssueApp.swift // Issue // // Created by Zhendong Chen on 2/1/25. // import SwiftUI @main struct IssueApp: App { var body: some Scene { WindowGroup { ContentView() } .windowStyle(.volumetric) } } // // ContentView.swift // Issue // // Created by Zhendong Chen on 2/1/25. // import SwiftUI import RealityKit import RealityKitContent struct ContentView: View { @State var enlarge = false var body: some View { RealityView { content, attachments in // Add the initial RealityKit content if let scene = try? await Entity(named: "Scene", in: realityKitContentBundle) { if let sphere = scene.findEntity(named: "Sphere") { sphere.components.set(UpAndDownComponent(speed: 0.03, minY: -0.05, maxY: 0.05)) } if let button = attachments.entity(for: "Button") { button.position.y -= 0.3 scene.addChild(button) } content.add(scene) } } attachments: { Attachment(id: "Button") { VStack { Button { SoundManager.instance.playSound(filePath: "apple_en") } label: { Text("Play audio") } .animation(.none, value: 0) .fontWeight(.semibold) } .padding() .glassBackgroundEffect() } } .onAppear { UpAndDownSystem.registerSystem() } } } // // SoundManager.swift // LinguaBubble // // Created by Zhendong Chen on 1/14/25. // import Foundation import AVFoundation class SoundManager { static let instance = SoundManager() private var audioPlayer: AVAudioPlayer? func playSound(filePath: String) { guard let url = Bundle.main.url(forResource: filePath, withExtension: ".mp3") else { return } do { audioPlayer = try AVAudioPlayer(contentsOf: url) audioPlayer?.play() } catch let error { print("Error playing sound. \(error.localizedDescription)") } } } // // UpAndDownComponent+System.swift // Issue // // Created by Zhendong Chen on 2/1/25. // import RealityKit struct UpAndDownComponent: Component { var speed: Float var axis: SIMD3<Float> var minY: Float var maxY: Float var direction: Float = 1.0 // 1 for up, -1 for down var initialY: Float? init(speed: Float = 1.0, axis: SIMD3<Float> = [0, 1, 0], minY: Float = 0.0, maxY: Float = 1.0) { self.speed = speed self.axis = axis self.minY = minY self.maxY = maxY } } struct UpAndDownSystem: System { static let query = EntityQuery(where: .has(UpAndDownComponent.self)) init(scene: RealityKit.Scene) {} func update(context: SceneUpdateContext) { let deltaTime = Float(context.deltaTime) // Time between frames for entity in context.entities(matching: Self.query, updatingSystemWhen: .rendering) { guard var component: UpAndDownComponent = entity.components[UpAndDownComponent.self] else { continue } // Ensure we have the initial Y value set if component.initialY == nil { component.initialY = entity.transform.translation.y } // Calculate the current position let currentY = entity.transform.translation.y // Move the entity up or down let newY = currentY + (component.speed * component.direction * deltaTime) // If the entity moves out of the allowed range, reverse the direction if newY >= component.initialY! + component.maxY { component.direction = -1.0 // Move down } else if newY <= component.initialY! + component.minY { component.direction = 1.0 // Move up } // Apply the new position entity.transform.translation = SIMD3<Float>(entity.transform.translation.x, newY, entity.transform.translation.z) // Update the component with the new direction entity.components[UpAndDownComponent.self] = component } } } Could someone help me with this?
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Feb ’25
How to request several models simultaneously
I am using HelloPhotogrammetry in Xcode I can make one model with something like HelloPhotogrammetry.main([path_to_folder_of images, path_to_output/model.usdz, "-d", "medium", "-o", "unordered", "-f", "high" ]) But how would I request several models simultaneously? I only want to vary the detail. [ ("/Users/you/Desktop/model_medium.usdz", detail: .medium), ("/Users/you/Desktop/model_full.usdz", detail: .full), ("/Users/you/Desktop/model_raw.usdz", detail: .raw ]
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Apr ’25
Converting a Stop Motion Animation to usdz
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!
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Apr ’25