Discuss Spatial Computing on Apple Platforms.

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RealityKit fullscreen layer
Hi! I'm currently trying to render another XR scene in front of a RealityKit one. Actually, I'm anchoring a plane to the head with a shader to display for left/right eye side-by-side images. By default, the camera has a near plane so I can directly draw at z=0. Is there a way to change the camera near plane? Or maybe there is a better solution to overlay image/texture for left/right eyes? Ideally, I would layer some kind of CompositorLayer on RealityKit, but that's sadly not possible from what I know. Thanks in advance and have a good day!
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Jul ’25
Accessing pupil diameter in visionOS
Previously I had developed software using SMI eye trackers, both screen mounted and their mobile glasses, for unique therapeutic and physiology applications. Sadly, after SMI was bought by Apple, their hardware and software have been taken off the market and now it is very difficult to get secondhand-market systems. The Apple Vision Pro integrates the SMI hardware. While I can use ARKit to get gaze position, I do not see a way to access information that was previously made accessible on the SMI hardware, particularly: dwell time and pupil diameter information. I am hopeful (or asking) to see that if a user has a properly set up Optic ID and would opt-in if, either on the present or a future version of visionOS, it might be possible to get access to the data streams for dwell times and pupil diameter. Pupil diameter is particularly important as it is a very good physiological measure of how much stress a person is encountering, which is critical to some of the therapeutic applications that formerly we used SMI hardware. Any ideas, or, if this is not possible, proposing this to the visionOS team would be appreciated!
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251
Jul ’25
visionOS: Unable to programmatically close child WindowGroup when parent window closes
Hi , I'm struggling with visionOS window management and need help with closing child windows programmatically. App Structure My app has a Main-Sub window hierarchy: AWindow (Home/Main) BWindow (Main feature window) CWindow (Tool window - child of BWindow) Navigation flow: AWindow → BWindow (switch, 1 window on screen) BWindow → CWindow (opens child, 2 windows on screen) I want BWindow and CWindow to be separate movable windows (not sheet/popover) so users can position them independently in space. The Problem CWindow doesn't close when BWindow closes by tapping the X button below the app (next to the window bar) User clicks X on BWindow → BWindow closes but CWindow remains CWindow becomes orphaned on screen Can close CWindow programmatically when switching BWindow back to AWindow App launch issue After closing both windows, CWindow is remembered as last window Reopening app shows only CWindow instead of BWindow User gets stuck in CWindow with no way back to BWindow I've Tried Environment dismissWindow in cleanup but its not working. // In BWindow.swift .onDisappear { if windowManager.isWindowOpen("cWindow") { dismissWindow(id: "cWindow") } } My App Structure Code Now // in MyNameApp.swift @main struct MyNameApp: App { var body: some Scene { WindowGroup(id: "aWindow") { AWindow() } WindowGroup(id: "bWindow") { BWindow() } WindowGroup(id: "cWindow") { CWindow() } } } // WindowStateManager.swift class WindowStateManager: ObservableObject { static let shared = WindowStateManager() @Published private var openWindows: Set<String> = [] @Published private var windowDependencies: [String: String] = [:] private init() {} func markWindowAsOpen(_ id: String) { markWindowAsOpen(id, parent: nil) } func markWindowAsClosed(_ id: String) { openWindows.remove(id) windowDependencies[id] = nil } func isWindowOpen(_ id: String) -> Bool { let isOpen = openWindows.contains(id) return isOpen } func markWindowAsOpen(_ id: String, parent: String? = nil) { openWindows.insert(id) if let parentId = parent { windowDependencies[id] = parentId } } func getParentWindow(of childId: String) -> String? { let parent = windowDependencies[childId] return parent } func getChildWindows(of parentId: String) -> [String] { let children = windowDependencies.compactMap { key, value in value == parentId ? key : nil } return children } func setNextWindowParent(_ parentId: String) { UserDefaults.standard.set(parentId, forKey: "nextWindowParent") } func getAndClearNextWindowParent() -> String? { let parent = UserDefaults.standard.string(forKey: "nextWindowParent") UserDefaults.standard.removeObject(forKey: "nextWindowParent") return parent } func forceCloseChildWindows(of parentId: String) { let children = getChildWindows(of: parentId) for child in children { markWindowAsClosed(child) NotificationCenter.default.post( name: Notification.Name("ForceCloseWindow"), object: nil, userInfo: ["windowId": child] ) forceCloseChildWindows(of: child) } } func hasMainWindowOpen() -> Bool { let mainWindows = ["main", "bWindow"] return mainWindows.contains { isWindowOpen($0) } } func cleanupOrphanWindows() { for (child, parent) in windowDependencies { if isWindowOpen(child) && !isWindowOpen(parent) { NotificationCenter.default.post( name: Notification.Name("ForceCloseWindow"), object: nil, userInfo: ["windowId": child] ) markWindowAsClosed(child) } } } } // BWindow.swift struct BWindow: View { @Environment(\.dismissWindow) private var dismissWindow @ObservedObject private var windowManager = WindowStateManager.shared var body: some View { VStack { Button("Open C Window") { windowManager.setNextWindowParent("bWindow") openWindow(id: "cWindow") } } .onAppear { windowManager.markWindowAsOpen("bWindow") } .onDisappear { windowManager.markWindowAsClosed("bWindow") windowManager.forceCloseChildWindows(of: "bWindow") } .onChange(of: scenePhase) { oldValue, newValue in if newValue == .background || newValue == .inactive { windowManager.forceCloseChildWindows(of: "bWindow") } } } } // CWindow.swift import SwiftUI struct cWindow: View { @ObservedObject private var windowManager = WindowStateManager.shared @State private var shouldClose = false var body: some View { // Content } .onDisappear { windowManager.markWindowAsClosed("cWindow") NotificationCenter.default.removeObserver( self, name: Notification.Name("ForceCloseWindow"), object: nil ) } .onChange(of: scenePhase) { oldValue, newValue in if newValue == .background { } } .onAppear { let parent = windowManager.getAndClearNextWindowParent() windowManager.markWindowAsOpen("cWindow", parent: parent) NotificationCenter.default.addObserver( forName: Notification.Name("ForceCloseWindow"), object: nil, queue: .main) { notification in if let windowId = notification.userInfo?["windowId"] as? String, windowId == "cWindow" { shouldClose = true } } } .onChange(of: shouldClose) { _, newValue in if newValue { dismissWindow() } } } The logs show everything executes correctly, but CWindow remains visible on screen. Questions Why doesn't dismissWindow(id:) work in cleanup scenarios? Is there a proper way to create a window relationships like parent-child relationships in visionOS? How can I ensure main windows open on app launch instead of tool windows? What's the recommended pattern for dependent windows in visionOS? Environment: Xcode 16.2, visionOS 2.0, SwiftUI
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349
Aug ’25
Pinning a pushed window to a wall breaks pushWindow for all other apps on the system
I posted https://developer.apple.com/forums/thread/809481 yesterday about an issue I discovered with pushWindow in visionOS 26.2 RC, but today I discovered a second problem with pushWindow. If window A calls pushWindow to present window B, and the user pins window B to a wall, the following unexpected behaviors are observed: Window B spontaneously disappears. If the user re-launches the (still running) app from the visionOS home view, both window A and window B appear simultaneously. I assume only window B should be visible at this point, since window A pushed window B. If the user closes window B, it's now impossible to present window B again. Calls to pushWindow appear to be ignored. If the user force-quits the app and relaunches it, and pushWindow is called again, window B appears, but window A remains visible. I also noticed this surprising behavior: This broken state of pushWindow behavior now affects all other apps on the system that may call pushWindow in the future, not just the app whose pushed window was pinned above. A workaround is to reboot the device, and then the system will behave as expected until the next time the user pins a pushed window.
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How to prevent system windows occlusion when using OcclusionMaterial
We use SceneReconstructionProvider to detect meshes in the surrounding environment and apply an OcclusionMaterial to them. // Assuming `entity` represents one of the detected mesh in the environment entity.components.set(ModelComponent( mesh: mesh, materials: [OcclusionMaterial()] )) While this correctly occludes entities placed in the immersive space, it also occludes system windows. This becomes problematic when a window is dragged into an occluded area (before or after entering the immersive space), preventing interaction with its elements. In some cases, it also makes it impossible to focus on the window’s drag handle, since this might become occluded as well after moving the window nearby. More generally, system windows can be occluded when they come into proximity with a model that has OcclusionMaterial applied. I'm aware of a change introduced in visionOS 2 regarding how occlusions interact with UI elements (as noted in the release notes). I believe this change was intended to ensure windows do not remain visible when opened in another room. However, this also introduces some challenges, as described in the scenario above. Is there a way to prevent system window occlusion while still allowing entities to be occluded by environmental features? Perhaps not using OcclusionMaterial at all? Development environment: Xcode 16.2, macOS 15.2 Run-time configuration: visionOS 2.2 and 2.3
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Feb ’25
Triangle Recommendation Limit for M5 Vision Pro
For the M2 Apple Vision Pro, there's "a general guideline, we recommend no more than 500 thousand triangles for an immersive scene, with 250 thousand for applications in the shared space." --https://developer.apple.com/videos/play/wwdc2024/10186/?time=147 Is there a revised recommendation for the M5 Apple Vision Pro?
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Nov ’25
Is it possible to live render CMTaggedBuffer / MV-HEVC frames in visionOS?
Hey all, I'm working on a visionOS app that captures live frames from the left and right cameras of Apple Vision Pro using cameraFrame.sample(for: .left/.right). Apple provides documentation on encoding side-by-side frames into MV-HEVC spatial video using CMTaggedBuffer: Converting Side-by-Side 3D Video to MV-HEVC My question: Is there any way to render tagged frames (e.g. CMTaggedBuffer with .stereoView(.leftEye/.rightEye)) live, directly to a surface in RealityKit or Metal, without saving them to a file? I’d like to create a true stereoscopic (spatial) live video preview, not just render two images side-by-side. Any advice or insights would be greatly appreciated!
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249
Aug ’25
version update in Vision Pro
Hi, I'm developing an app for Vision Pro using Xcode, while updating the latest update, things that worked in my app suddenly didn't. in my app flow I'm tapping spheres to get their positions, from some reason I get an offset from where I tap to where a marker on that position is showing up. here's the part of code that does that, and a part that is responsible for an alignment that happens afterwards: func loadMainScene(at position: SIMD3) async { guard let content = self.content else { return } do { let rootEntity = try await Entity(named: "surgery 16.09", in: realityKitContentBundle) rootEntity.scale = SIMD3<Float>(repeating: 0.5) rootEntity.generateCollisionShapes(recursive: true) self.modelRootEntity = rootEntity let bounds = rootEntity.visualBounds(relativeTo: nil) print("📏 Model bounds: center=\(bounds.center), extents=\(bounds.extents)") let pivotEntity = Entity() pivotEntity.addChild(rootEntity) self.pivotEntity = pivotEntity let modelAnchor = AnchorEntity(world: [1, 1.3, -0.8]) modelAnchor.addChild(pivotEntity) content.add(modelAnchor) updateModelOpacity(0.5) self.modelAnchor = modelAnchor rootEntity.visit { entity in print("👀 Entity in model: \(entity.name)") if entity.name.lowercased().hasPrefix("focus") { entity.generateCollisionShapes(recursive: true) entity.components.set(InputTargetComponent()) print("🎯 Made tappable: \(entity.name)") } } print("✅ Model loaded with collisions") guard let sphere = placementSphere else { return } let sphereWorldXform = sphere.transformMatrix(relativeTo: nil) var newXform = sphereWorldXform newXform.columns.3.y += 0.1 // move up by 20 cm let gridAnchor = AnchorEntity(world: newXform) self.gridAnchor = gridAnchor content.add(gridAnchor) let baseScene = try await Entity(named: "Scene", in: realityKitContentBundle) let gridSizeX = 18 let gridSizeY = 10 let gridSizeZ = 10 let spacing: Float = 0.05 let startX: Float = -Float(gridSizeX - 1) * spacing * 0.5 + 0.3 let startY: Float = -Float(gridSizeY - 1) * spacing * 0.5 - 0.1 let startZ: Float = -Float(gridSizeZ - 1) * spacing * 0.5 for i in 0..<gridSizeX { for j in 0..<gridSizeY { for k in 0..<gridSizeZ { if j < 2 || j > gridSizeY - 5 { continue } // remove 2 bottom, 4 top let cell = baseScene.clone(recursive: true) cell.name = "Sphere" cell.scale = .one * 0.02 cell.position = [ startX + Float(i) * spacing, startY + Float(j) * spacing, startZ + Float(k) * spacing ] cell.generateCollisionShapes(recursive: true) gridCells.append(cell) gridAnchor.addChild(cell) } } } content.add(gridAnchor) print("✅ Grid added") } catch { print("❌ Failed to load: \(error)") } } private func handleModelOrGridTap(_ tappedEntity: Entity) { guard let modelRootEntity = modelRootEntity else { return } let localPosition = tappedEntity.position(relativeTo: modelRootEntity) let worldPosition = tappedEntity.position(relativeTo: nil) switch tapStep { case 0: modelPointA = localPosition modelAnchor?.addChild(createMarker(at: worldPosition, color: [1, 0, 0])) print("📍 Model point A: \(localPosition)") tapStep += 1 case 1: modelPointB = localPosition modelAnchor?.addChild(createMarker(at: worldPosition, color: [1, 0.5, 0])) print("📍 Model point B: \(localPosition)") tapStep += 1 case 2: targetPointA = worldPosition targetMarkerA = createMarker(at: worldPosition,color: [0, 1, 0]) modelAnchor?.addChild(targetMarkerA!) print("✅ Target point A: \(worldPosition)") tapStep += 1 case 3: targetPointB = worldPosition targetMarkerB = createMarker(at: worldPosition,color: [0, 0, 1]) modelAnchor?.addChild(targetMarkerB!) print("✅ Target point B: \(worldPosition)") alignmentReady = true tapStep += 1 default: print("⚠️ Unexpected tap on model helper at step \(tapStep)") } } func alignModel2Points() { guard let modelPointA = modelPointA, let modelPointB = modelPointB, let targetPointA = targetPointA, let targetPointB = targetPointB, let modelRootEntity = modelRootEntity, let pivotEntity = pivotEntity, let modelAnchor = modelAnchor else { print("❌ Missing data for alignment") return } let modelVec = modelPointB - modelPointA let targetVec = targetPointB - targetPointA let modelLength = length(modelVec) let targetLength = length(targetVec) let scale = targetLength / modelLength let modelDir = normalize(modelVec) let targetDir = normalize(targetVec) var axis = cross(modelDir, targetDir) let axisLength = length(axis) var rotation = simd_quatf() if axisLength < 1e-6 { if dot(modelDir, targetDir) > 0 { rotation = simd_quatf(angle: 0, axis: [0,1,0]) } else { let up: SIMD3<Float> = [0,1,0] axis = cross(modelDir, up) if length(axis) < 1e-6 { axis = cross(modelDir, [1,0,0]) } rotation = simd_quatf(angle: .pi, axis: normalize(axis)) } } else { let dotProduct = dot(modelDir, targetDir) let clampedDot = max(-1.0, min(dotProduct, 1.0)) let angle = acos(clampedDot) rotation = simd_quatf(angle: angle, axis: normalize(axis)) } modelRootEntity.scale = .one * scale modelRootEntity.orientation = rotation let transformedPointA = rotation.act(modelPointA * scale) pivotEntity.position = -transformedPointA modelAnchor.position = targetPointA alignedModelPosition = modelAnchor.position print("✅ Aligned with scale \(scale), rotation \(rotation)")
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292
Oct ’25
Performance drop when particle emitter is combined with video play
Hi All, We're a studio building an app and as part of a scene we have a 3D asset with a smoke particle emitter and a curved mesh that plays video. I notice that when the video alone is played or the particle effect alone is done then the scene works fine but the frame rate drops drastically when both are turned on. How do I solve this because this is an important storytelling feature.
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292
Oct ’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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97
Apr ’25
Nearby Sharing a Volume won't work
Hi, we've developed an app for Vision Pro that utilises the GroupActivitites SDK to provide shared experiences for our users. Remote Participation works great, but we can't get nearby sharing to work. The behaviour we're observing: User 1 engages share sheet from Volume, 2nd Vision Pro is visible. User 1 starts nearby sharing Session initialisation runs for approx. 30 seconds, then fails Sometimes, the nearby participant doesn't show up at all after the initialisation has failed once. As stated in the Configure your visionOS app for sharing with people nearby article, we didn't make any changes to our implementation to support nearby sharing. Any help would be greatly appreciated. Kind regards, David
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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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166
Apr ’25
How to configure Spatial Audio on a Video Material?, Compile error.
I've tried following apple's documentation to apply a video material on a Model Entity, but I have encountered a compile error while attempting to specify the Spatial Audio type. It is a 360 video on a Sphere which plays just fine, but the audio is too quiet compared to the volume I get when I preview the video on Xcode. So I tried tried to configure audio playback mode on the material but it gives me a compile error: "audioInputMode' is unavailable in visionOS audioInputMode' has been explicitly marked unavailable here RealityFoundation.VideoPlaybackController.audioInputMode)" https://developer.apple.com/documentation/realitykit/videomaterial/ Code: let player = AVPlayer(url: url) // Instantiate and configure the video material. let material = VideoMaterial(avPlayer: player) // Configure audio playback mode. material.controller.audioInputMode = .spatial // this line won’t compile. VisionOS 2.4, Xcode 16.4, also tried Xcode 26 beta 2. The videos are HEVC MPEG-4 codecs. Is there any other way to do this, or is there a workaround available? Thank you.
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241
Jul ’25
How to trigger other effects using hoverEffect?
I’m facing an issue while using CustomHoverEffect. In my view, there is a long title, which causes the title to be truncated. When the user hovers over it, the title should scroll. Although I have already implemented the scrolling effect, I am unsure how to trigger the scroll on hover. How should I approach this?
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376
Feb ’25
Volumetric window not sharing in SharePlay session for VisionOS
I've been struggling with this for far too long so I've decided to finally come here and see if anyone can point me to the documentation that I'm missing. I'm sure it's something so simple but I just can't figure it out. I can SharePlay our test app with my brother (device to device) but when I open a volumetric window, it says "not shared" under it. I assume this will likely fix the video sharing problem we have as well. Everything else works so smooth but SharePlay has just been such a struggle for me. It's the last piece to the puzzle before we can put it on the App Store.
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132
Sep ’25
Building a custom render pipeline with RealityKit
Hello experts, and question seekers, I have been trying to get Gaussian splats working with RealityKit, however it seems not to work out for me. The library I use for Gaussian splatting: https://github.com/scier/MetalSplatter My idea was to use the renderers provided by RealityKit (aka RealityRenderer) https://developer.apple.com/documentation/realitykit/realityrenderer and the renderer provided by MetalSplatter (aka. SplatRenderer) https://github.com/scier/MetalSplatter/blob/main/MetalSplatter/Sources/SplatRenderer.swift Then with a custom render pipeline, I would be able to compose the outputs of the renderers, enabling the possibility, for example to build immersive scenery with realistic environment scans, as Gaussian splats, and RealityKit to provide the necessary features to build extra scenery around Gaussian splats, eg. dynamic 3D models inside Gaussian splats. However the problem is, as of now I am not able to do that with the current implementation of RealityRenderer. It seems to be, that first RealityRenderer is supposed to be an API, just to render colour information onto a texture, which in first glance might be useful, but misses important information, such as for example depth, and stencil information. Second issue is, even with that in mind, currently I am not able to execute RealityRenderer.updateAndRender, due to the following error messages: Could not resolve material name 'engine:BuiltinRenderGraphResources/Common/realityRendererBackground.rematerial' in bundle at '/Users//Library/Developer/CoreSimulator/Devices//data/Containers/Bundle/Application//.app'. Loading via asset path. exiting spatial tracking service update thread because wait returned 37” I was able to build a custom Metal view with UIViewRepresentable, MTKView, and MTKViewDelegate, enabling me to build a custom rendering pipeline, by utilising some of the Metal developer workflows. Reference: https://developer.apple.com/documentation/xcode/metal-developer-workflows/ Inside draw(in view: MTKView), in a class derived by MTKViewDelegate: guard let currentDrawable = view.currentDrawable else { return } let realityRenderer = try! RealityRenderer() try! realityRenderer.updateAndRender(deltaTime: 0.0, cameraOutput: .init(.singleProjection(colorTexture: currentDrawable.texture)), whenScheduled: { realityRenderer in print("Rendering scheduled") }, onComplete: { RealityRenderer in print("Rendering completed") }) Can you please tell me, what I am doing wrong? Is there any solution, that enables me to use RealityKit with for example Gaussian splats? Any help is greatly appreciated. All the best, Ethem Kurt
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774
Feb ’25