Discuss Spatial Computing on Apple Platforms.

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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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249
Apr ’25
.glassEffect() view modifier in visionOS 26 beta 1 generates an error
.glassEffect(.regular, in: .rect(cornerRadius: 24)) error; 'glassEffect(_:in:isEnabled:)' is unavailable in visionOS This is not surprising since visionOS already has a native glass interface that formed a model for the other OS's, but this error will create additional overhead for developers creating multi-platform apps that include visionOS.
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175
Jun ’25
How do we use the new Unified Coordinate Conversion features in visionOS 26?
The landing page for visionOS 26 mentions The Unified Coordinate Conversion API makes moving views and entities between scenes straightforward — even between views and ARKit accessory anchors. This WWDC session very briefly shows a single example of using this, but with no context. For example, they discuss a way to tell the distance between a Model3D and an entity in a RealityView. But they don't provide any details for how they are referencing the entity (bolts in the slide). The session used the BOT-anist example project that we saw in visionOS 2, but the version on in the Sample Code library has not been updated with these examples. I was able to put together a simple example where we can get the position of a window relative to the world origin. It even updates when the user recenters. struct Lab080: View { @State private var posX: Float = 0 @State private var posY: Float = 0 @State private var posZ: Float = 0 var body: some View { GeometryReader3D { geometry in VStack { Text("Unified Coordinate Conversion") .font(.largeTitle) .padding(24) VStack { Text("X: \(posX)") Text("Y: \(posY)") Text("Z: \(posZ)") } .font(.title) .padding(24) } .onGeometryChange3D(for: Point3D.self) { proxy in try! proxy .coordinateSpace3D() .convert(value: Point3D.zero, to: .worldReference) } action: { old, new in posX = Float(new.x) posY = Float(new.y) posZ = Float(new.z) } } } } This is all that I've been able to figure out so far. What other features are included in this new Unified Coordinate Conversion? Can we use this to get the position of one window relative to another? Can we use this to get the position of a view in a window relative to an entity in a RealityView, for example in a Volume or Immersive Space? What else can Unified Coordinate Conversion do? Are there documentation pages that I'm missing? I'm not sure what to search for. Are there any Sample projects that use these features? Any additional information would be very helpful.
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1.5k
Sep ’25
SharePlay on the VisionOS with remote participants.
Hi everyone, I’m building a visualization app for VisionPro that uses SharePlay and GroupActivities to explore datasets collaboratively. I’ve successfully implemented the new SharedWorldAnchor feature, and everything works well with nearby, local participants. However, I’m stuck on one point: How can I share a world anchor with remote participants who join via FaceTime as spatial personas? Apple’s demo app (where multiple users move a plane model around) seems to suggest that this is possible. For context, I’m building an immersive app with Metal rendering. Any guidance or examples would be greatly appreciated! Thanks, Jens
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450
Sep ’25
How to create a MultiplayerDelegate and use TabletopNetworkSession features?
When building a multiplayer Tabletop game, the documentation includes how to attach a custom TabletopNetworkSessionCoordinator, which could be used in addition to TabletopGame.MultiplayerDelegate. But so far, we have been unable to create these types of custom coordinators or have a delegate that works. Our current setup with our generic GroupActivity works by sending the session to TabletopGame's coordinateWithSession method (like in the current sample project), but we didn't find a way to access and control, for example, the arbiter, seats, player events, among other features mentioned on https://developer.apple.com/documentation/tabletopkit/tabletopnetworksession. Is correct to expect having access to the participants, messenger, or journal without having to maintain a parallel coordinator?   possibly we are missing something here; any suggestions?
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305
Apr ’25
Shared/GroupImmersive Space – Query Local Device Transform
Hi, I am in the process of implementing SharePlay into our app. The shared experience opens an Immersive Space and we set systemCoordinator.configuration.supportsGroupImmersiveSpace = true Now visionOS establishes a shared coordinate space for the immersive space. From the docs: To achieve consistent positioning of RealityKit entities across multiple devices in an immersive space during a SharePlay session There are cases where we want to position content in front of the user (independent of the shared session, and for each user individually). Normally to do that we use the transform retrieved via worldTrackingProvider.queryDeviceAnchor.originFromAnchorTransform to position content in front of the user (plus some Z Offset and smooth interpolation). This works fine in non-SharePlay instances and the device transform is where I would expect it to be but during the FaceTime call deviceAnchor.originFromAnchorTransform seems to use the shared origin of the immersive space and then I end up with a transform that might be offset. Here is a video of the issue in action: https://streamable.com/205r2p The blue rect is place using AnchorEntity(.head, trackingMode: .continuous). This works regardless of the call and the entity is always placed based on the head position. The green rect is adjusted on every frame using the transform I get from worldTrackingProvider.queryDeviceAnchor. As you can see it's offset. Is there any way I can query query this transform locally for the user during a FaceTime call? Also I would like to know if it's possible to disable this automatic entity transform syncing behavior? Setting entity.synchronization = nil results in the entity not showing up at all. https://developer.apple.com/documentation/realitykit/synchronizationcomponent Is SynchronizationComponent only relevant for the legacy MultiPeerConnectivity approach? Thank you!
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373
Oct ’25
HoverEffectStyle in visionOS 26.0
This is no longer highlighting my entity when looking at it: RealityView { content let hoverComponent = HoverEffectComponent(.spotlight( HoverEffectComponent.SpotlightHoverEffectStyle( color: .white, strength: 2.0 ) )) entity.components.set(hoverComponent) The entity is in a window. The same code works in an immersive view. Collision Component and Input type are set in RCP. It's also stopped working on my published app (built under visionOS 2.x) using my visionOS 26 device. If I use a 2.x simulator, it works. Is this a bug or is there something I'm missing? Thanks.
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863
Oct ’25
Getting the world position of a QR code
Hi, would love for your help in that matter. I try to get the position in space of two QR codes to make an alignment to their positions in space. The detection shows that the QR codes position is always 0,0,0 and I don't understand why. Here's my code: import SwiftUI import RealityKit import RealityKitContent struct AnchorView: View { @ObservedObject var qrCoordinator: QRCoordinator @ObservedObject var coordinator: ImmersiveCoordinator let qrName: String @Binding var startQRDetection: Bool @State private var anchor: AnchorEntity? = nil @State private var detectionTask: Task<Void, Never>? = nil var body: some View { RealityView { content in // Add the QR anchor once (must exist before detection starts) if anchor == nil { let imageAnchor = AnchorEntity(.image(group: "QRs", name: qrName)) content.add(imageAnchor) anchor = imageAnchor print("📌 Created anchor for \(qrName)") } } .onChange(of: startQRDetection) { enabled in if enabled { startDetection() } else { stopDetection() } } .onDisappear { stopDetection() } } private func startDetection() { guard detectionTask == nil, let anchor = anchor else { return } detectionTask = Task { var detected = false while !Task.isCancelled && !detected { print("🔎 Checking \(qrName)... isAnchored=\(anchor.isAnchored)") if anchor.isAnchored { // wait a short moment to let transform update try? await Task.sleep(nanoseconds: 100_000_000) let worldPos = anchor.position(relativeTo: nil) if worldPos != .zero { // relative to modelRootEntity if available var posToSave = worldPos if let modelEntity = coordinator.modelRootEntity { posToSave = anchor.position(relativeTo: modelEntity) print("converted to model position") } else { print("⚠️ modelRootEntity not available, using world position") } print("✅ \(qrName) detected at position: world=\(worldPos) saved=\(posToSave)") if qrName == "reanchor1" { qrCoordinator.qr1Position = posToSave let marker = createMarker(color: [0,1,0]) marker.position = .zero // sits directly on QR marker.position = SIMD3<Float>(0, 0.02, 0) anchor.addChild(marker) print("marker1 added") } else if qrName == "reanchor2" { qrCoordinator.qr2Position = posToSave let marker = createMarker(color: [0,0,1]) marker.position = posToSave // sits directly on QR marker.position = SIMD3<Float>(0, 0.02, 0) anchor.addChild(marker) print("marker2 added") } detected = true } else { print("⚠️ \(qrName) anchored but still at origin, retrying...") } } try? await Task.sleep(nanoseconds: 500_000_000) // throttle loop } print("🛑 QR detection loop ended for \(qrName)") detectionTask = nil } } private func stopDetection() { detectionTask?.cancel() detectionTask = nil } private func createMarker(color: SIMD3<Float>) -> ModelEntity { let sphere = MeshResource.generateSphere(radius: 0.05) let material = SimpleMaterial(color: UIColor( red: CGFloat(color.x), green: CGFloat(color.y), blue: CGFloat(color.z), alpha: 1.0 ), isMetallic: false) let marker = ModelEntity(mesh: sphere, materials: [material]) marker.name = "marker" return marker } }
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498
Oct ’25
CompositorServices Or RealityKit
I have been concentrating on developing the visionOS application. While I am currently quite familiar with RealityKit, CompositorServices has also captured my attention. I have not yet acquired knowledge of CompositorServices. Could you please clarify whether it is essential for me to learn CompositorServices? Additionally, I would appreciate it if you could provide insights into the advantages of RealityKit and CompositorServices.
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799
Mar ’25
How to update TextureResource with MTLTexture?
Hi I have a monitoring app, that will take input video from uvc and process it using Metal, and eventually get a MTLTexture. The problem I'm facing is I have to convert MTLTexture to CGImage then call TextureResource.replace, which is super slow. Metal processing speed is same as input frame rate(50pfs), but MTLTexture -> CGImage -> TextureResource only got 7fps... Is there any way I can make it faster?
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512
Oct ’25
VisionPro camera frame rate
Hi, I'm working with CameraFrameProvider from Enterprise API. Is it always capped at 30fps, or is there something I can switch to get more? I assume it is capped at 30, so let me cram in additional question here :). If I'd get a developer strap and attach an external camera capable of doing >30fps, will I get the full stream, or some other limitation will kick in?
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135
Apr ’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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325
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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335
Oct ’25