Discuss spatial computing on Apple platforms and how to design and build an entirely new universe of apps and games for Apple Vision Pro.

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How to implement the semi-transparent overlay effect in Immersive View?
I noticed that when I drag the menu window in an Immersive View, the entities behind it becomes semi-transparent, and the boundary between virtual and real-world objects is very pronounced. May I ask how does VisionOS implement this effect? Is there any API or technique I can use in my own code to enable the same semi-transparent overlay - even when I am not dragging the menu window?
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May ’25
The folding and unfolding effect of the NBA sand table
Seeing this magical sand table, the unfolding and folding effects are similar to spreading out cards, which is very interesting. But I don't know how to achieve it. I want to see if there are any ways to achieve this effect and give some ideas. May I ask if this effect can be achieved under the existing API
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May ’25
Launching a timeline on a specific model via notification
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?
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May ’25
Is `ParticleEmitterComponent` implemented for `RealityKit` on iOS?
Hi there, I was looking to add a particle emitter to my augmented reality app I'm developing using RealityKit. I'm targeting iOS. I noticed in the documentation for the ParticleEmitterComponent that it looks like iOS 18.0+ is supported, but when I try to use the ParticleEmitterComponent in my code in XCode, I get an error that it isn't found. Furthermore, this StackOverflow post seems to indicate that particle systems are not available for iOS. Would it be possible to get clarification on this?
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May ’25
Vision Pro stucks on "Retrieving configuration"
Hi, after upgrading to 2.4.1 (from 1.0) my vision stucks on "Retrieving configuration" screen. Apple Store didn't support my case since it has been sold in USA and the product isn't still present in italian market. I don't have dev strap, how can I manage the issue? Thank you
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May ’25
Can not remove final World Anchor
I’ve been having some issues removing anchors. I can add anchors with no issue. They will be there the next time I run the scene. I can also get updates when ARKit sends them. I can remove anchors, but not all the time. The method I’m using is to call removeAnchor() on the data provider. worldTracking.removeAnchor(forID: uuid) // Yes, I have also tried `removeAnchor(_ worldAnchor: WorldAnchor)` This works if there are more than one anchor in a scene. When I’m down to one remaining anchor, I can remove it. It seems to succeed (does not raise an error) but the next time I run the scene the removed anchor is back. This only happens when there is only one remaining anchor. do { // This always run, but it doesn't seem to "save" the removal when there is only one anchor left. try await worldTracking.removeAnchor(forID: uuid) } catch { // I have never seen this block fire! print("Failed to remove world anchor \(uuid) with error: \(error).") } I posted a video on my website if you want to see it happening. https://stepinto.vision/labs/lab-051-issues-with-world-tracking/ Here is the full code. Can you see if I’m doing something wrong? Is this a bug? struct Lab051: View { @State var session = ARKitSession() @State var worldTracking = WorldTrackingProvider() @State var worldAnchorEntities: [UUID: Entity] = [:] @State var placement = Entity() @State var subject : ModelEntity = { let subject = ModelEntity( mesh: .generateSphere(radius: 0.06), materials: [SimpleMaterial(color: .stepRed, isMetallic: false)]) subject.setPosition([0, 0, 0], relativeTo: nil) let collision = CollisionComponent(shapes: [.generateSphere(radius: 0.06)]) let input = InputTargetComponent() subject.components.set([collision, input]) return subject }() var body: some View { RealityView { content in guard let scene = try? await Entity(named: "WorldTracking", in: realityKitContentBundle) else { return } content.add(scene) if let placementEntity = scene.findEntity(named: "PlacementPreview") { placement = placementEntity } } update: { content in for (_, entity) in worldAnchorEntities { if !content.entities.contains(entity) { content.add(entity) } } } .modifier(DragGestureImproved()) .gesture(tapGesture) .task { try! await setupAndRunWorldTracking() } } var tapGesture: some Gesture { TapGesture() .targetedToAnyEntity() .onEnded { value in if value.entity.name == "PlacementPreview" { // If we tapped the placement preview cube, create an anchor Task { let anchor = WorldAnchor(originFromAnchorTransform: value.entity.transformMatrix(relativeTo: nil)) try await worldTracking.addAnchor(anchor) } } else { Task { // Get the UUID we stored on the entity let uuid = UUID(uuidString: value.entity.name) ?? UUID() do { try await worldTracking.removeAnchor(forID: uuid) } catch { print("Failed to remove world anchor \(uuid) with error: \(error).") } } } } } func setupAndRunWorldTracking() async throws { if WorldTrackingProvider.isSupported { do { try await session.run([worldTracking]) for await update in worldTracking.anchorUpdates { switch update.event { case .added: let subjectClone = subject.clone(recursive: true) subjectClone.isEnabled = true subjectClone.name = update.anchor.id.uuidString subjectClone.transform = Transform(matrix: update.anchor.originFromAnchorTransform) worldAnchorEntities[update.anchor.id] = subjectClone print("🟢 Anchor added \(update.anchor.id)") case .updated: guard let entity = worldAnchorEntities[update.anchor.id] else { print("No entity found to update for anchor \(update.anchor.id)") return } entity.transform = Transform(matrix: update.anchor.originFromAnchorTransform) print("🔵 Anchor updated \(update.anchor.id)") case .removed: worldAnchorEntities[update.anchor.id]?.removeFromParent() worldAnchorEntities.removeValue(forKey: update.anchor.id) print("🔴 Anchor removed \(update.anchor.id)") if let remainingAnchors = await worldTracking.allAnchors { print("Remaining Anchors: \(remainingAnchors.count)") } } } } catch { print("ARKit session error \(error)") } } } }
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May ’25
RoomPlan - The delegate of ARSession is retaining x ARFrames
Hi, I'm encountering an issue in our app that uses RoomPlan and ARsession for scanning. After prolonged use—especially under heavy load from both the scanning process and other unrelated app operations—the iPhone becomes very hot, and the following warning begins to appear more frequently: "ARSession <0x107559680>: The delegate of ARSession is retaining 11 ARFrames. The camera will stop delivering camera images if the delegate keeps holding on to too many ARFrames. This could be a threading or memory management issue in the delegate and should be fixed." I was able to reproduce this behavior using Apple’s RoomPlanExampleApp, with only one change: I introduced a CPU-intensive workload at the end of the startSession() function: DispatchQueue.global().asyncAfter(deadline: .now() + 5) { for i in 0..<4 { var value = 10_000 DispatchQueue.global().async { while true { value *= 10_000 value /= 10_000 value ^= 10_000 value = 10_000 } } } } I suspect this is some RoomPlan API problem that's why a filed an feedback: 17441091
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May ’25
Cannot reassign worldTracking / planeDetection providers in my PlacementManager when switching environments
Environment Xcode: 16.2 VisionOS SDK 2.4 Swift 6.1 Targets: Apple Vision Pro (immersive space) Frameworks: ARKit, RealityKit, SwiftUI What I’m Trying to Do I have a view-model class PlacementManager that holds two AR providers: private var worldTracking: WorldTrackingProvider private var planeDetection: PlaneDetectionProvider I want to dynamically replace these providers in a setEnvironment(_:) method (so I can save/clear a JSON scene and restart ARKit). What’s Happening If I declare them as : private let worldTracking = WorldTrackingProvider() private let planeDetection = PlaneDetectionProvider() I get compile-errors when I later do: self.worldTracking = newWorldTracking // Cannot assign to property: 'worldTracking' is a 'let' constant If I change them to un-initialized vars: private var worldTracking: WorldTrackingProvider private var planeDetection: PlaneDetectionProvider then in my init() I get: self used in property access 'worldTracking' before all stored properties are initialized Code snipet @Observable final class PlacementManager : ObservableObject { private var worldTracking: WorldTrackingProvider private var planeDetection: PlaneDetectionProvider // … other props … @MainActor init() { // error: self.worldTracking used before init… planeAnchorHandler = PlaneAnchorHandler(rootEntity: root) persistenceManager = PersistenceManager( worldTracking: worldTracking, rootEntity: root ) // … } @MainActor func setEnvironment(env: Environnement) async { let newWorldTracking = WorldTrackingProvider() let newPlaneDetection = PlaneDetectionProvider() try await appState!.arkitSession.run( [ newWorldTracking, newPlaneDetection ] ) self.worldTracking = newWorldTracking self.planeDetection = newPlaneDetection // … } } What I’ve Tried Giving them default values at declaration (= WorldTrackingProvider()) Initializing them at the top of init() before any use Passing the new providers into arkitSession.run(...) My Question What is the recommended Swift-style pattern to declare and reassign these ARKit provider properties so that: They’re fully initialized before use in init(), and I can swap them out later in setEnvironment(...) without compiler errors? Any pointers (or links to forum threads / docs) would be greatly appreciated!
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May ’25
Playing USDZ animation at last known location of reference object
Hi there I'm using Reality Composer Pro to anchor virtual content to a .referenceobject. However moving the referenceobject quickly causes tracking to stop. (I know this is a limitation and I am trying to embrace it as a feature) Is there a way to play a USDZ animation at the last known location, after detecting that the reference object is no longer tracked? is it possible to set this up in Reality Composer pro? I'm trying to get the USDZ to play before the Virtual Content disappears (due to reference object not being located). So that it smooths out the vanishing of the content. Nearly everything is set up in Reality Composer pro with my immersive.scene just adding virtual content to the reference object which anchors it in the RCP Scene, so my immersive view just does this - if let immersiveContentEntity = try? await Entity(named: "Immersive", in: realityKitContentBundle) { content.add(immersiveContentEntity) & this .onAppear { appModel.immersiveSpaceState = .open } .onDisappear { appModel.immersiveSpaceState = .closed } I have tried Using SpatialTracking & WorldTrackingProvider, but I'm still quite new to Swift and coding in general so im unsure how to implement in conjunction with my RCP scene and/or if this is the right way to go about it. Also I have implemented this at the beginning of object tracking. All I had to do was add a onAppear behavior to the object to play a USDZ and that works. Doing it for disappearing (due to loss of reference object) seems to be a lot harder.
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Apr ’25
Playing USDZ animation at last known location of reference object
Hi there I'm using Reality Composer Pro to anchor virtual content to a .referenceobject. However by moving the referenceobject quickly, it causes tracking to stop. (I know this is a limitation so im trying to make it a feature) IS there a way to play a USDZ animation at the last known location, after detecting that reference object is no longer being tracked? is it possible to set this up in Reality Composer pro? Nearly everything is set up in Reality Composer pro with my immersive.scene just anchoring virtual content to the Reference object in the RCP Scene, so my immersive view just does this - if let immersiveContentEntity = try? await Entity(named: "Immersive", in: realityKitContentBundle) { content.add(immersiveContentEntity) & this .onAppear { appModel.immersiveSpaceState = .open } .onDisappear { appModel.immersiveSpaceState = .closed } I have tried Using SpatialTracking & WorldTrackProvider, but I'm still quite new to Swift and coding in general so im unsure how to implement in conjunction with my RCP scene and if this is actually the right way to do it. Apologies for my lack of knowledge.
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Apr ’25
How to obtain video streams from the digital space included in VisionPro after applying for the "Enterprise API"?
After implementing the method of obtaining video streams discussed at WWDC in the program, I found that the obtained video stream does not include digital models in the digital space or related videos such as the program UI. I would like to ask how to obtain a video stream or frame that contains only the physical world? let formats = CameraVideoFormat.supportedVideoFormats(for: .main, cameraPositions:[.left]) let cameraFrameProvider = CameraFrameProvider() var arKitSession = ARKitSession() var pixelBuffer: CVPixelBuffer? var cameraAccessStatus = ARKitSession.AuthorizationStatus.notDetermined let worldTracking = WorldTrackingProvider() func requestWorldSensingCameraAccess() async { let authorizationResult = await arKitSession.requestAuthorization(for: [.cameraAccess]) cameraAccessStatus = authorizationResult[.cameraAccess]! } func queryAuthorizationCameraAccess() async{ let authorizationResult = await arKitSession.queryAuthorization(for: [.cameraAccess]) cameraAccessStatus = authorizationResult[.cameraAccess]! } func monitorSessionEvents() async { for await event in arKitSession.events { switch event { case .dataProviderStateChanged(_, let newState, let error): switch newState { case .initialized: break case .running: break case .paused: break case .stopped: if let error { print("An error occurred: \(error)") } @unknown default: break } case .authorizationChanged(let type, let status): print("Authorization type \(type) changed to \(status)") default: print("An unknown event occured \(event)") } } } @MainActor func processWorldAnchorUpdates() async { for await anchorUpdate in worldTracking.anchorUpdates { switch anchorUpdate.event { case .added: //检查是否有持久化对象附加到此添加的锚点- //它可能是该应用程序之前运行的一个世界锚。 //ARKit显示与此应用程序相关的所有世界锚点 //当世界跟踪提供程序启动时。 fallthrough case .updated: //使放置的对象的位置与其对应的对象保持同步 //世界锚点,如果未跟踪锚点,则隐藏对象。 break case .removed: //如果删除了相应的世界定位点,则删除已放置的对象。 break } } } func arkitRun() async{ do { try await arKitSession.run([cameraFrameProvider,worldTracking]) } catch { return } } @MainActor func processDeviceAnchorUpdates() async { await run(function: self.cameraFrameUpdatesBuffer, withFrequency: 90) } @MainActor func cameraFrameUpdatesBuffer() async{ guard let cameraFrameUpdates = cameraFrameProvider.cameraFrameUpdates(for: formats[0]),let cameraFrameUpdates1 = cameraFrameProvider.cameraFrameUpdates(for: formats[1]) else { return } for await cameraFrame in cameraFrameUpdates { guard let mainCameraSample = cameraFrame.sample(for: .left) else { continue } self.pixelBuffer = mainCameraSample.pixelBuffer } for await cameraFrame in cameraFrameUpdates1 { guard let mainCameraSample = cameraFrame.sample(for: .left) else { continue } if self.pixelBuffer != nil { self.pixelBuffer = mergeTwoFrames(frame1: self.pixelBuffer!, frame2: mainCameraSample.pixelBuffer, outputSize: CGSize(width: 1920, height: 1080)) } } }
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Apr ’25
Unity PolySpatial – Live handheld camera feed of graspable objects not rendering on Vision Pro
I am developing a Unity application for the Apple Vision Pro using PolySpatial and RealityKit integration. The goal is to create a graspable object (for example, a handheld cube) that includes a secondary camera. When the user grabs and moves the object, the secondary camera should render its view to a RenderTexture, which is displayed on a quad attached to the object, simulating a live camera screen. In the Unity Editor, this setup works correctly. The RenderTexture updates in real time, and the quad displays the camera’s view as expected. However, when building and running the application on the Vision Pro, the quad only displays the clear background color of the secondary camera. No scene content appears. The graspable interaction itself works fine: the object can be grabbed and moved as intended. Steps I have taken: Created a new layer (CameraFeed) and assigned the relevant objects to it. Set the secondary camera’s culling mask to render only the CameraFeed layer. Assigned the RenderTexture as the camera’s target texture. Applied the RenderTexture to an Unlit/Texture material on a quad. Confirmed the camera is active and correctly positioned relative to the object. From my research, it appears that once objects are managed by RealityKit through PolySpatial (for example, made graspable), they are no longer rendered through Unity's normal camera pipeline. Only the main XR camera (managed by RealityKit) seems able to see these objects. Secondary Unity cameras cannot render RealityKit-synced content to a RenderTexture. If this is correct, it seems there is currently no way to implement a true live secondary camera feed showing graspable objects on Vision Pro using Unity PolySpatial. My questions are: Is there any official way to enable multiple camera rendering of RealityKit-managed objects through PolySpatial? Are there known workarounds to simulate a live camera feed that still allows objects to be grabbed? Has anyone found alternative design patterns or methods for this kind of interaction? Environment: Unity 6.0 , PolySpatial 2.2.4, Apple Vision OS XR 2.2.4 Any insight or suggestions would be greatly appreciated. Thank you.
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Apr ’25
How to read a video stream that includes both the physical world and digital space when obtaining a video stream from VisionPro by applying for the Enterprise API but only reading a video stream that contains both the physical world and digital space
We have successfully obtained the permissions for "Main Camera access" and "Passthrough in screen capture" from Apple. Currently, the video streams we have received are from the physical world and do not include the digital world. How can we obtain video streams from both the physical and digital worlds? thank you!
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Apr ’25
attenuation map covers over object
hi, I'm trying to create a virtual movie theater, but after running computeDiffuseReflectionUVs.py and applying attenuation map, I noticed the light falloff effect just covers over the objects. I used apple provided attenuation map (did not specify the attenuation map name on python script) with sample size of 6000. I thought the python script would calculate vertices and create shadow for, say, back of the chairs. Am I understanding this wrong?
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Apr ’25
Transparent Material Turning into Occlusion Material
I am trying to create an object in immersive space that is partially transparent (~50% opacity). I have implemented this in a few different ways including creating a model entity and setting its opacity component to 0.5, and creating a custom material with blending set to a transparent opacity of 0.5. These both work partially, as they behaved as intended for many cases, but seemingly randomly would act like occlusion material and block any other immersive content behind them, showing the real world instead. Some notes: I am using RealityKit to render the semi-transparent object and an opaque object that is behind the semi-transparent object. I am using VisionOS 2.1, and am updating the location of the semi-transparent object often. Both objects are ModelEntities. I would appreciate any guidance on how to implement this. Please let me know if there are any other questions.
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Apr ’25
Animation handling on Scene change
I work on a game where I use timeline animations in Reality Composer Pro. The game runs in an immersive space, but can be paused where I then move the whole level root entity from the immersive space to another RealityView in a Window Group. When the player continues I do it exactly the other way around to move the level root from the window group back to my immersive space RealityView. And it seems like all animations get automatically stopped and restarted when the scene gets changed. The problem is, it does not resume where it stopped before, it completely starts again from where it stopped and therefore, has for example a wrong y offset as visible in the picture. For example in the picture, the yellow sphere loops the following animation: 0 to 100 100 to -100 -100 to 0 If I now pause the game (and basically switch scenes), the previous animation gets stopped and restarted at position y = 100. So now it loops: 100 to 200 200 to 0 0 to 100 I already tried all kind of setups - like: Setting the animations relative to root, parent, local Using behaviors (on Added to Scene, on Notification) And finally even by accessing the availableAnimations directly and saving the playback controller of the animation There I saw, if I manually trigger the following code before switching the scene, everything works as expected: Button("Reset") { animationPlaybackController.time = 0 animationPlaybackController.pause() animationPlaybackController.stop(blendOutDuration: 0.00001) } But if I use time = 0 with .stop() directly, the time = 0 seems to be ignored and I get the same behavior as before that it stops in a wrong y offset, hence my assumption that animations get stopped and invalidated once they change the scene. I tried to call the code manually on ImmersiveSpace.onDisappear, WindowGroup.onAppear and different kind of SceneEvents subscriptions, but unfortunately nothing worked. So am I doing something wrong in general or is there a way to fix this?
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Apr ’25