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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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350
Feb ’25
Volumetric Windwos anchores
Hi, we would like to create something where you can open multiple volumetric windows and place them in a room, our biggest issue is that we want these windows to be persistent, so when I close and reopen the app, the windows to be in the same position. We can't use immersive spaces because we also want to have the possibility to access the shared space. Is it possible with the current features and capabilities to do that? If yes do you have some advices how can we achieve this? The alternative is if is it possible to open the virtual display in immersive spaces or if we have the possibility to implement our own virtual display.
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395
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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92
Apr ’25
Reading Imagefiles outside of app content
Hi there. Thanks to amazing help from you guys, I've managed to code a 360 image carousel, where the user can browse 360 images located inside the project package. Is there a way to access the filesystem on AVP outside the app? I know about the FileManager, and I can get access to the .documentsDirectory, but how do I access documents folder from the "Files" app on the AVP? My goal is to read images from a hardcoded folderlocation on the AVP, such that the user never will have to select the images themselves. I know this may not be the "right" way to do this. The app is supposed to be "foolproof" with a minimum of userinteraction. The only way to change the images should be to change the contents of the hardcoded imagefolder. I hope this makes sense =) Thanks in advance! Regards, Kim
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275
Feb ’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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148
Apr ’25
RealityKit / visionOS – Memory not released after dismissing ImmersiveSpace with USDZ models
Hi everyone, I’m encountering a memory overflow issue in my visionOS app and I’d like to confirm if this is expected behavior or if I’m missing something in cleanup. App Context The app showcases apartments in real scale using AR. Apartments are heavy USDZ models (hundreds of thousands of triangles, high-resolution textures). Users can walk inside the apartments, and performance is good even close to hardware limits. Flow The app starts in a full immersive space (RealityView) for selecting the apartment. When an apartment is selected, a new ImmersiveSpace opens and the apartment scene loads. The scene includes multiple USDZ models, EnvironmentResources, and dynamic textures for skyboxes. When the user dismisses the experience, we attempt cleanup: Nulling out all entity references. Removing ModelComponents. Clearing cached textures and skyboxes. Forcing dictionaries/collections to empty. Despite this cleanup, memory usage remains very high. Problem After dismissing the ImmersiveSpace, memory does not return to baseline. Check the attached screenshot of the profiling made using Instruments: Initial state: ~30MB (main menu). After loading models sequentially: ~3.3GB. Skybox textures bring it near ~4GB. After dismissing the experience (at ~01:00 mark): memory only drops slightly (to ~2.66GB). When loading the second apartment, memory continues to increase until ~5GB, at which point the app crashes due to memory pressure. The issue is consistently visible under VM: IOSurface in Instruments. No leaks are detected. So it looks like RealityKit (or lower-level frameworks) keeps caching meshes and textures, and does not free them when RealityView is ended. But for my use case, these resources should be fully released once the ImmersiveSpace is dismissed, since new apartments will load entirely different models and textures. Cleanup Code Example Here’s a simplified version of the cleanup I’m doing: func clearAllRoomEntities() { for (entityName, entity) in entityFromMarker { entity.removeFromParent() if let modelEntity = entity as? ModelEntity { modelEntity.components.removeAll() modelEntity.children.forEach { $0.removeFromParent() } modelEntity.clearTexturesAndMaterials() } entityFromMarker[entityName] = nil removeSkyboxPortals(from: entityName) } entityFromMarker.removeAll() } extension ModelEntity { func clearTexturesAndMaterials() { guard var modelComponent = self.model else { return } for index in modelComponent.materials.indices { removeTextures(from: &modelComponent.materials[index]) } modelComponent.materials.removeAll() self.model = modelComponent self.model = nil } private func removeTextures(from material: inout any Material) { if var pbr = material as? PhysicallyBasedMaterial { pbr.baseColor.texture = nil pbr.emissiveColor.texture = nil pbr.metallic.texture = nil pbr.roughness.texture = nil pbr.normal.texture = nil pbr.ambientOcclusion.texture = nil pbr.clearcoat.texture = nil material = pbr } else if var simple = material as? SimpleMaterial { simple.color.texture = nil material = simple } } } Questions Is this expected RealityKit behavior (textures/meshes cached internally)? Is there a way to force RealityKit to release GPU resources tied to USDZ models when they’re no longer used? Should dismissing the ImmersiveSpace automatically free those IOSurfaces, or do I need to handle this differently? Any guidance, best practices, or confirmation would be hugely appreciated. Thanks in advance!
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1.9k
5d
Unity on VisionOS development - best practice on structuring a project
Hello, I am experimenting with Unity to develop a mixed reality (MR) application for visionOS. I would like to understand the best approach for structuring my project: Should I build the entire experience in Unity (both Windows and Volumes)? Or is it better to create only certain elements (e.g., Volumes) in Unity while managing Windows separately in Xcode? Also, how well do interactions (e.g pinch, grab…) created in Unity integrate with Xcode? If I use the PolySpatial plugin, does that allow me to manage all interactions entirely within Unity, or would I still need to handle/integrate part of it in Xcode? What's worked best for you? Please let me know if you have any recommendations, Thanks!
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132
Apr ’25
Ornaments in Presentations
We can add ornaments to popovers shown by PresentationComponent, but I’m not sure if we should. While working on the editor for entities in a Volume-based app, I had the idea to add ornaments to the presented views. The entire app exists inside a volume. A user can tap a item to present a popoverUI to edit it. This is displayed using the new PresentationComponent in visionOS 26. Ornaments have a new attachment anchor option this year: .parent(). .ornament(attachmentAnchor: .parent(.top), ornament: {...}) This works well in the Simulator. We can add ornaments around this popover view just like we would with a window. Unfortunately, when I run this on device I get a different experience. Any part of the ornament that overlaps with the popover content isn’t rendered correctly. Sometimes it entirely disappears, other times it becomes partially transparent. We could use content alignment to try to make sure the ornament doesn’t overlap the popover content. .ornament(attachmentAnchor: .parent(.top), contentAlignment: .bottom, ornament: {...}) This works sometimes–but not all the time. It’s not clear if this is a bug or not, because I’m not sure if we are even supposed to be able to use ornaments in this way. Here is my hierarchy: An app opens as a Volume Volume presenting a RealityView, with its own ornament using .scene() anchor Multiple Entities with Presentation Component show an edit view The view uses .parent() anchor to add ornaments. What makes me unsure is that other methods for drawing UI in RealityView don’t seem to work with ornaments. For example, if I add an attachment to show a view with the ornament–even when I use the .parent() anchor–the ornament is anchor to the volume, not the attachment view. So what do we think? Is this a rendering bug? Are ornaments intended to work with attachments and presentations?
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352
Aug ’25
Obect Capture App getting rejected for not supporting non Pro Models
Hi, I created an app using iOS Object Capture API which works only on Lidar enabled phones. It's a limitation of the Api provided by apple itself. I Submitted an app for Review , but It is getting rejected (Twice) saying it doesnt work on non pro models. Even though I explained that capturing Needs Lidar and supported only in PRO models, It still gets rejected after testing in Non Pro models. is there a way out?
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350
Feb ’25
Unable to Create a Fully Immersive Experience That Hides Other Windows in visionOS App
Description: I'm developing a travel/panorama viewing app for visionOS that allows users to view 360° panoramic images in an immersive space. When users enter panorama viewing mode, I want to provide a fully immersive experience where the main interface window and Earth 3D globe window are hidden. I've implemented the app following Apple's documentation on Creating Fully Immersive Experiences, but when users enter the immersive space, both the main window and the Earth 3D window remain visible, diminishing the immersive experience. Implementation Details: My app has three main components: A main content window showing panorama thumbnails A 3D globe window (volumetric) showing locations An immersive space for viewing 360° panoramas I'm using .immersionStyle(selection: $panoImageView, in: .full) to create a fully immersive experience, but other windows remain visible. Relevant Code: @main struct Travel_ImmersiveApp: App { @StateObject private var appModel = AppModel() @State private var panoImageView: ImmersionStyle = .full var body: some Scene { WindowGroup { ContentView() .environmentObject(appModel) } .windowStyle(.automatic) .defaultSize(width: 1280, height: 825) WindowGroup(id: "Earth") { Globe3DView() .environmentObject(appModel) .onAppear { appModel.isGlobeWindowOpen = true appModel.globeWindowOpen = true } .onDisappear { if !appModel.shouldCloseApp { appModel.handleGlobeWindowClose() } } } .windowStyle(.volumetric) .defaultSize(width: 0.8, height: 0.8, depth: 0.8, in: .meters) .windowResizability(.contentSize) ImmersiveSpace(id: "ImmersiveView") { ImmersiveView() .environmentObject(appModel) } .immersionStyle(selection: $panoImageView, in: .full) } } Opening the Immersive Space: func getPanoImageAndOpenImmersiveSpace() async { appModel.clearMemoryCache() do { let canView = appModel.canViewImage(image) if canView { let downloadedImage = try await appModel.getPanoramaImage(for: image) { progress in Task { @MainActor in cardState = .loading(progress: progress) } } await MainActor.run { appModel.updateCurrentImage(image, panoramaImage: downloadedImage) } if !appModel.immersiveSpaceOpened { try await openImmersiveSpace(id: "ImmersiveView") await MainActor.run { appModel.immersiveSpaceOpened = true cardState = .normal } } else { await MainActor.run { appModel.updateImmersiveView = true cardState = .normal } } } else { await MainActor.run { appModel.errorMessage = "You do not have permission to view this image." cardState = .normal } } } catch { // Error handling } } Immersive View Implementation: struct ImmersiveView: View { @EnvironmentObject var appModel: AppModel var body: some View { RealityView { content in let rootEntity = Entity() content.add(rootEntity) Task { if let selectedImage = appModel.selectedImage, appModel.canViewImage(selectedImage) { await loadPanorama(for: rootEntity) } } } update: { content in if appModel.updateImmersiveView, let selectedImage = appModel.selectedImage, appModel.canViewImage(selectedImage), let rootEntity = content.entities.first { Task { await loadPanorama(for: rootEntity) appModel.updateImmersiveView = false } } } .onAppear { print("ImmersiveView appeared") } .onDisappear { appModel.resetImmersiveState() } } // loadPanorama implementation... } What I've Tried Set immersionStyle to .full as recommended in the documentation Confirmed that the immersive space is properly opened and displaying panoramas Verified that the state management for the immersive space is working correctly Questions How can I ensure that when the user enters the immersive panorama viewing experience, all other windows (main interface and Earth 3D globe) are automatically hidden? Is there a specific API or approach I'm missing to properly implement a fully immersive experience that hides all other windows? Do I need to manually dismiss the windows when opening the immersive space, and if so, what's the best approach for doing this? Any guidance or sample code would be greatly appreciated. Thank you!
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140
Apr ’25
FromToByAnimation triggers availableAnimations not the single bone animation
So, I was trying to animate a single bone using FromToByAnimation, but when I start the animation, the model instead does the full body animation stored in the availableAnimations. If I don't run testAnimation nothing happens. If I run testAnimation I see the same animation as If I had called entity.playAnimation(entity.availableAnimations[0],..) here's the full code I use to animate a single bone: func testAnimation() { guard let jawAnim = jawAnimation(mouthOpen: 0.4) else { print("Failed to create jawAnim") return } guard let creature, let animResource = try? AnimationResource.generate(with: jawAnim) else { return } let controller = creature.playAnimation(animResource, transitionDuration: 0.02, startsPaused: false) print("controller: \(controller)") } func jawAnimation(mouthOpen: Float) -> FromToByAnimation<JointTransforms>? { guard let basePose else { return nil } guard let index = basePose.jointNames.firstIndex(of: jawBoneName) else { print("Target joint \(self.jawBoneName) not found in default pose joint names") return nil } let fromTransforms = basePose.jointTransforms let baseJawTransform = fromTransforms[index] let maxAngle: Float = 40 let angle: Float = maxAngle * mouthOpen * (.pi / 180) let extraRot = simd_quatf(angle: angle, axis: simd_float3(x: 0, y: 0, z: 1)) var toTransforms = basePose.jointTransforms toTransforms[index] = Transform( scale: baseJawTransform.scale * 2, rotation: baseJawTransform.rotation * extraRot, translation: baseJawTransform.translation ) let fromToBy = FromToByAnimation<JointTransforms>( jointNames: basePose.jointNames, name: "jaw-anim", from: fromTransforms, to: toTransforms, duration: 0.1, bindTarget: .jointTransforms, repeatMode: .none, ) return fromToBy } PS: I can confirm that I can set this bone to a specific position if I use guard let index = newPose.jointNames.firstIndex(of: boneName) ... let baseTransform = basePose.jointTransforms[index] newPose.jointTransforms[index] = Transform( scale: baseTransform.scale, rotation: baseTransform.rotation * extraRot, translation: baseTransform.translation ) skeletalComponent.poses.default = newPose creatureMeshEntity.components.set(skeletalComponent) This works for manually setting the bone position, so the jawBoneName and the joint-transformation can't be that wrong.
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262
Aug ’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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248
Jul ’25
How to display stereo images in Apple Vision Pro?
Hi community, I have a pair of stereo images, one for each eye. How should I render it on visionOS? I know that for 3D videos, the AVPlayerViewController could display them in fullscreen mode. But I couldn't find any docs relating to 3D stereo images. I guess my question can be brought up in a more general way: Is there any method that we can render different content for each eye? This could also be helpful to someone who only has sight on one eye.
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4.8k
Mar ’25