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Distortion Artifacts on VisionOS When Rendering Opaque/Alpha Clipped Foliage in URP (Unity 6.0, Metal)
I'm running into a persistent visual issue while deploying a floral corridor scene to Apple Vision Pro using Unity 6.0 with URP and Metal. The issue only appears on the Vision Pro device — everything looks fine in the Unity Editor. Issue Description When the frame rate drops to around 60–70 FPS, noticeable distortion artifacts appear around the edges of foliage models. It seems like the background meshes (behind the plants) get warped and leak through the edges of the foliage. Although this is most visible around the leaves, even solid objects like standard URP wall or box models show distorted edges when the issue occurs. All the foliage uses Opaque or Alpha Clipping materials. Things I've Tried Changing the foliage materials to Transparent mode —distortion around edges disappears, but using Transparent for a large number of foliage assets is not ideal for performance or sorting complexity. Reducing the number of foliage objects — with only a few plants in the scene and the frame rate staying around 100 FPS, the distortion disappears. However, this isn’t a practical solution for a full environment. Possible Cause? I came across this note in the Unity documentation: "Ensure depth-buffer for each pixel is non-zero - on visionOS, the depth buffer is used for reprojection. To ensure visual effects like skyboxes and shaders are displayed beautifully, ensure that some value is written to the depth for each pixel." Could this be related to the issue? Is it possible that Alpha Clipping with low pixel coverage leads to some pixels not writing to the depth buffer, which then causes problems during Vision Pro’s reprojection or foveated rendering? However, even when I disable Alpha Clipping entirely, the distortion issue still persists, so it may not be solely caused by clipping itself. Project Setup Unity 6.0 (URP) Depth Texture: Enable Using Metal as the graphics backend Running on real Vision Pro hardware (not simulator) Any advice on how to avoid these distortion issues on Vision Pro would be greatly appreciated. Thanks!
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137
Jul ’25
- (BOOL) contentsAreFlipped needs to be true for .nib layouts
I have an odd bug, if I use initWithFrame as the init routine for NSView subclass that uses layers I don't see this bug. But if I embedded this view into a storyboard with a .nib file and use initWithCoder, I need to return true on (BOOL) contentsAreFlipped From the NSView subclass If I don't the CALayer actually renders from 0,0 from the view upwards and off the window. The frame sizes for the NSView and the CALayer are good.. when I see them in updateLayer. Obviously I have a fix.. but I would like to understand why.
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264
Jan ’26
Krazy Krownz multiplayer option not working for Game Center!
When trying to play with friends Krazy Krownz doesn’t allow me to click multiplayer even though my Apple Game Center connected and my friends Apple game center connected as well. I even tried sending an invite from Apple Game Center to friends and Krazy Krownz doesn’t even show up on the list of available multiplayer games. I’ve signed out and back in the same issue remain. I’ve try to contact the game developer, but the website doesn’t work.
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281
Jan ’26
vsync, drawable present, instrument gui
hi When analyzing our game using Instruments, I've always been confused about the two items "Drawable Present" and "Drawable Presented" in the GPU column. The timing of Drawable Present seems to be when the CPU layer calls commandbuffer:present, rather than when the actual encoding is completed on the GPU. Also, what does drawable presented specifically mean? In our case, when a CPU stall occurs, it appears that the vsync interval changes in the next frame, and a surface that has already been calculated is not displayed. Why is this happening?
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165
May ’25
MetalFX FrameInterpolator assertion: `Color texture width mismatch from descriptor` even when all texture sizes match
I am integrating MetalFX FrameInterpolator into a custom Unity RenderGraph–based render pipeline (C++ native plugin + C# render passes), and I am hitting the following assertion at runtime: /MetalFXDebugError.h:29: failed assertion `Color texture width mismatch from descriptor' What makes this confusing is that all input/output textures have the correct width and height, and they exactly match the values specified in the MTLFXFrameInterpolatorDescriptor. Setup Input resolution: 1024 x 512 Output resolution: 2048 x 1024 MTLFXTemporalScaler is created first and then passed into MTLFXFrameInterpolator The TemporalScaler and FrameInterpolator descriptors use the same input/output sizes and formats All Metal textures: Have no parentTexture Are 2D textures Match the descriptor sizes exactly (verified via logging) Texture bindings at encode time frameInterpolator.colorTexture = mtlTexColor; // 1024 x 512 frameInterpolator.prevColorTexture = mtlTexPrevColor; // 1024 x 512 frameInterpolator.motionTexture = mtlTexMotion; // 1024 x 512 frameInterpolator.depthTexture = mtlTexDepth; // 1024 x 512 frameInterpolator.uiTexture = mtlTexUI; // 2048 x 1024 frameInterpolator.outputTexture = mtlTexOutput; // 2048 x 1024 All widths/heights are logged and match: Color : 1024 x 512 (input) PrevColor : 1024 x 512 (input) Motion : 1024 x 512 (input) Depth : 1024 x 512 (input) UI : 2048 x 1024 (output) Output : 2048 x 1024 (output) The TemporalScaler works correctly on its own. The assertion only occurs when using FrameInterpolator. Important detail about colorTexture Originally, colorTexture was copied from BuiltinRenderTextureType.CurrentActive. After reading that this might violate MetalFX semantics, I changed the pipeline so that: colorTexture now comes from a dedicated private RenderGraph texture It is not the backbuffer It is not a drawable It is not used as a final output It is created before UI rendering Despite this, the assertion still occurs. Question Can uiTexture for MTLFXFrameInterpolator legally come from a texture copied from BuiltinRenderTextureType.CurrentActive? More generally: Are there additional hidden constraints on colorTexture / prevColorTexture (such as Metal usage, storageMode, aliasing, or hazard tracking) that could cause this assertion, even when sizes match? Does FrameInterpolator require colorTexture and prevColorTexture to be created in a very specific way (e.g. non-aliased, ShaderRead usage, identical Metal resource properties)? Any clarification on the exact semantic requirements for colorTexture, prevColorTexture, or uiTexture in MetalFX FrameInterpolator would be greatly appreciated.
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599
Jan ’26
Regression: RealityKit spatial audio crackles and pops on iOS 26.0 beta 5 (FB19423059)
RealityKit spatial audio crackles and pops on iOS 26.0 beta 5. It works correctly on iOS 18.6 and visionOS 26.0 beta 5. The APIs used are AudioPlaybackController, Entity.prepareAudio, Entity.play Videos of the expected and observed behavior are attached to the feedback FB19423059. The audio should be a consistent, repeating sound, but it seems oddly abbreviated and the volume varies unexpectedly. Thank you for investigating this issue.
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307
Aug ’25
Terminal Codes
Hello Apple Developers and users I am writing this message reguarding some help on some performance codes/settings I can use for my Macbook since I recently downloaded the MacOs Tahoe 26.2 and its been very glitchy and laggy with gaming and just using my mac normally I have tried using a FPS unlocker and downloading Metal 4 the FPS unlocker hasent worked at all I am still stuck on the normal 60 FPS and need some advice/help. Thank you. Kind regards Zachary
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117
2w
SpriteKit Offline Rendering with SKRenderer
Hi! I'd like to share a technical sample app, SKRenderer Demo. This app demonstrates: Setting up SKRenderer Recording SpriteKit scenes to image sequences Recording SpriteKit scenes to video using IOSurface and AVFoundation Applying Core Image filters Exploring SpriteKit's simulation timing and physics determinism Use Case Record SpriteKit simulations as video or images for sharing and creating content. I explored several approaches, including the excellent view.texture(from:crop:) for live recording from SKView. The SKRenderer approach assumes recording happens asynchronously: you capture user interactions as commands during live interaction, then replay those commands through an offline render pass to generate the final output. I hope this helps others working on replay systems, simulation capture, or SpriteKit projects in general!
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226
Jan ’26
TapGesture stops responding on ViewAttachmentComponent after disabling or removing and re-adding the Entity (visionOS 26)
Issue When an Entity with a ViewAttachmentComponent is: disabled using isEnabled = false removed using removeFromParent() and then enabled or added back again, the attached SwiftUI view is rendered correctly, but tap interactions stop working. Specifically: Button actions inside the attached view do not fire TapGesture closures on child views do not respond Expected Behavior Tap interactions inside the attached view should continue to work after the Entity is re-enabled or re-added. Actual Behavior After being disabled or removed once, all tap interactions stop responding. Comparison When displaying the same SwiftUI view using RealityViewAttachments, this issue does not occur. Removing and re-displaying the attachment still allows taps to work correctly. Reproduction Attached sample code reproduces the issue: A RealityView with an Entity that has a ViewAttachmentComponent The attached SwiftUI view contains a Toggle The toggle updates isEnabled on the Entity After toggling off and on, tap interactions stop responding Environment Xcode 26 visionOS 26 Question Is this expected behavior of ViewAttachmentComponent, or a bug? Is there a recommended way to temporarily hide or disable an Entity with ViewAttachmentComponent without breaking tap interactions? import SwiftUI import RealityKit struct GestureTestView: View { @State var sampleEnabled = true @State var sampleEntity: Entity? var body: some View { RealityView { contents, attachments in // After deleting and re-displaying it, taps no longer respond. let sample = Entity(components: ViewAttachmentComponent(rootView: SampleView())) // Executed successfully //let sample = attachments.entity(for: "SampleView")! contents.add(sample) sample.position = [0, 1.2, -1] sampleEntity = sample let toggleButton = Entity(components: ViewAttachmentComponent(rootView: ToggleButtonView(isOn: $sampleEnabled))) contents.add(toggleButton) toggleButton.position = [0, 1, -1] } update: { _, _ in // run update closure print(sampleEnabled) // update sample entity enable sampleEntity?.isEnabled = sampleEnabled } attachments: { Attachment(id: "SampleView") { SampleView() } } } } struct ToggleButtonView: View { @Binding var isOn: Bool var body: some View { VStack { Toggle(isOn: $isOn) { Text("Toggle") } } .padding() .glassBackgroundEffect() } } struct SampleView: View { var body: some View { VStack { Button { print("Hello, World!") } label: { Text("Hello, World!") .padding() } } .padding() .glassBackgroundEffect() } } #Preview(immersionStyle: .mixed) { GestureTestView() }
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474
Jan ’26
moveCharacter reports collision with itself
I'm running into an issue with collisions between two entities with a character controller component. In the collision handler for moveCharacter the collision has both hitEntity and characterEntity set to the same object. This object is the entity that was moved with moveCharacter() The below example configures 3 objects. stationary sphere with character controller falling sphere with character controller a stationary cube with a collision component if the falling sphere hits the stationary sphere then the collision handler reports both hitEntity and characterEntity to be the falling sphere. I would expect that the hitEntity would be the stationary sphere and the character entity would be the falling sphere. if the falling sphere hits the cube with a collision component the the hit entity is the cube and the characterEntity is the falling sphere as expected. Is this the expected behavior? The entities act as expected visually however if I want the spheres to react differently depending on what character they collided with then I am not getting the expected results. IE: If a player controlled character collides with a NPC then exchange resource with NPC. if player collides with enemy then take damage. import SwiftUI import RealityKit struct ContentView: View { @State var root: Entity = Entity() @State var stationary: Entity = createCharacter(named: "stationary", radius: 0.05, color: .blue) @State var falling: Entity = createCharacter(named: "falling", radius: 0.05, color: .red) @State var collisionCube: Entity = createCollisionCube(named: "cube", size: 0.1, color: .green) //relative to root @State var fallFrom: SIMD3<Float> = [0,0.5,0] var body: some View { RealityView { content in content.add(root) root.position = [0,-0.5,0.0] root.addChild(stationary) stationary.position = [0,0.05,0] root.addChild(falling) falling.position = fallFrom root.addChild(collisionCube) collisionCube.position = [0.2,0,0] collisionCube.components.set(InputTargetComponent()) } .gesture(SpatialTapGesture().targetedToAnyEntity().onEnded { tap in let tapPosition = tap.entity.position(relativeTo: root) falling.components.remove(FallComponent.self) falling.teleportCharacter(to: tapPosition + fallFrom, relativeTo: root) }) .toolbar { ToolbarItemGroup(placement: .bottomOrnament) { HStack { Button("Drop") { falling.components.set(FallComponent(speed: 0.4)) } Button("Reset") { falling.components.remove(FallComponent.self) falling.teleportCharacter(to: fallFrom, relativeTo: root) } } } } } } @MainActor func createCharacter(named name: String, radius: Float, color: UIColor) -> Entity { let character = ModelEntity(mesh: .generateSphere(radius: radius), materials: [SimpleMaterial(color: color, isMetallic: false)]) character.name = name character.components.set(CharacterControllerComponent(radius: radius, height: radius)) return character } @MainActor func createCollisionCube(named name: String, size: Float, color: UIColor) -> Entity { let cube = ModelEntity(mesh: .generateBox(size: size), materials: [SimpleMaterial(color: color, isMetallic: false)]) cube.name = name cube.generateCollisionShapes(recursive: true) return cube } struct FallComponent: Component { let speed: Float } struct FallSystem: System{ static let predicate: QueryPredicate<Entity> = .has(FallComponent.self) && .has(CharacterControllerComponent.self) static let query: EntityQuery = .init(where: predicate) let down: SIMD3<Float> = [0,-1,0] init(scene: RealityKit.Scene) { } func update(context: SceneUpdateContext) { let deltaTime = Float(context.deltaTime) for entity in context.entities(matching: Self.query, updatingSystemWhen: .rendering) { let speed = entity.components[FallComponent.self]?.speed ?? 0.5 entity.moveCharacter(by: down * speed * deltaTime, deltaTime: deltaTime, relativeTo: nil) { collision in if collision.hitEntity == collision.characterEntity { print("hit entity has collided with itself") } print("\(collision.characterEntity.name) collided with \(collision.hitEntity.name) ") } } } } #Preview(windowStyle: .volumetric) { ContentView() }
1
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178
Aug ’25
How can I assign priorities to my app’s GPU workloads?
My app has a number of heterogeneous GPU workloads that all run concurrently. Some of these should be executed with the highest priority because the app’s responsiveness depends on them, while others are triggered by file imports and the like which should have a low priority. If this was running on the CPU I’d assign the former User Interactive QoS and the latter Utility QoS. Is there an equivalent to this for GPU work?
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938
Jan ’26
Unable to profile Metal app on M2 Ultra (profiling works on M3 Pro)
On MacBook Pro M3 14" I can profile the Metal App performance by running it, then clicking on the M icon and choosing profile after replay. On Mac Studio M2 Ultra I cannot: the profiler starts and crashes. I have tried everything including reinstalling the OS, Xcode, the Metal SDK, you name it. The app uses the Metal 4 API. The content of the replayer errorinfo report is shown at the end. Any ideas what is going on here and/or what else I can do do root cause this and fix it? FWIW, it was worse on 26.1 (Xcode just reported Metal 4 profiling not available). In 26.2 Xcode attempts to profile and invariably crashes. === Error summary: === 1x DYErrorDomain (512) - guest app crashed (512) 1x com.apple.gputools.MTLReplayer (100) - Abort trap: 6 === First Error === Domain: DYErrorDomain Error code: 512 Description: guest app crashed (512) GTErrorKeyPID: 26913 GTErrorKeyProcessName: GPUToolsReplayService GTErrorKeyCrashDate: 2026-01-09 19:22:52 +0000 === Underlying Error #1 === Domain: com.apple.gputools.MTLReplayer Error code: 100 Description: Abort trap: 6 Call stack: 0 GPUToolsReplay 0x0000000249c25850 MakeNSError + 284 1 GPUToolsReplay 0x0000000249c26428 HandleCrashSignal + 252 2 libsystem_platform.dylib 0x00000001856c7744 _sigtramp + 56 3 libsystem_pthread.dylib 0x00000001856bd888 pthread_kill + 296 4 libsystem_c.dylib 0x00000001855c2850 abort + 124 5 libsystem_c.dylib 0x00000001855c1a84 err + 0 6 IOGPU 0x00000001a9ea60a8 -[IOGPUMetal4CommandQueue _commit:count:commitFeedback:].cold.1 + 0 7 IOGPU 0x00000001a9ea0df8 __77-[IOGPUMetal4CommandQueue commitFillArgs:count:args:argsSize:commitFeedback:]_block_invoke + 0 8 IOGPU 0x00000001a9ea1004 -[IOGPUMetal4CommandQueue _commit:count:commitFeedback:] + 148 9 AGXMetalG14X 0x00000001158a2c98 -[AGXG14XFamilyCommandQueue_mtlnext noMergeCommit:count:options:commitFeedback:error:] + 116 10 AGXMetalG14X 0x0000000115a45c14 +[AGXG14XFamilyRenderContext_mtlnext mergeRenderEncoders:count:options:commitFeedback:queue:error:] + 4740 11 AGXMetalG14X 0x00000001158a2b34 -[AGXG14XFamilyCommandQueue_mtlnext commit:count:options:] + 96 12 GPUToolsReplay 0x0000000249bf0644 GTMTLReplayController_defaultDispatchFunction_noPinning + 2744 13 GPUToolsReplay 0x0000000249befb10 GTMTLReplayController_defaultDispatchFunction + 1368 14 GPUToolsReplay 0x0000000249b7a61c _ZL16DispatchFunctionP21GTMTLReplayControllerPK11GTTraceFuncRb + 476 15 GPUToolsReplay 0x0000000249b8603c ___ZN35GTUSCSamplingStreamingManagerHelper19StreamFrameTimeDataEv_block_invoke + 456 16 Foundation 0x0000000186f6c878 __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 24 17 Foundation 0x0000000186f6c740 -[NSBlockOperation main] + 96 18 Foundation 0x0000000186f6c6d8 __NSOPERATION_IS_INVOKING_MAIN__ + 16 19 Foundation 0x0000000186f6c308 -[NSOperation start] + 640 20 Foundation 0x0000000186f6c080 __NSOPERATIONQUEUE_IS_STARTING_AN_OPERATION__ + 16 21 Foundation 0x0000000186f6bf70 __NSOQSchedule_f + 164 22 libdispatch.dylib 0x00000001855104d0 _dispatch_block_async_invoke2 + 148 23 libdispatch.dylib 0x000000018551aad4 _dispatch_client_callout + 16 24 libdispatch.dylib 0x00000001855056e4 _dispatch_continuation_pop + 596 25 libdispatch.dylib 0x0000000185504d58 _dispatch_async_redirect_invoke + 580 26 libdispatch.dylib 0x0000000185512fc8 _dispatch_root_queue_drain + 364 27 libdispatch.dylib 0x0000000185513784 _dispatch_worker_thread2 + 180 28 libsystem_pthread.dylib 0x00000001856b9e10 _pthread_wqthread + 232 29 libsystem_pthread.dylib 0x00000001856b8b9c start_wqthread + 8 Replayer breadcrumbs: [ ] GTErrorKeyProcessSignal: SIGABRT === Setup === Capture device: star.localdomain (Mac14,14) - macOS 26.2 (25C56) - 0BA10D1D-D340-5F2E-934B-536675AF9BA1 Metal version: 370.64.2 Supported graphics APIs: Metal device: Apple M2 Ultra Supported GPU families: Apple1 Apple2 Apple3 Apple4 Apple5 Apple6 Apple7 Apple8 Mac1 Mac2 Common1 Common2 Common3 Metal3 Metal4 Replay device: star (Mac14,14) - macOS 26.2 (25C56) - 0BA10D1D-D340-5F2E-934B-536675AF9BA1 Metal version: 370.64.2 Supported graphics APIs: Metal device: Apple M2 Ultra Supported GPU families: Apple1 Apple2 Apple3 Apple4 Apple5 Apple6 Apple7 Apple8 Mac1 Mac2 Common1 Common2 Common3 Metal3 Metal4 Host: Mac14,14 - macOS 26.2 (25C56) Tool: Xcode (17C52) Known SDKs:
1
0
393
Jan ’26
How to add and remove child entities to a rigged entity in RealityKit?
I am currently using RealityKit (perspective camera) to render a character in my swiftUI app. The character has customization such as clothing items and hair and all objects are properly weighted to the rig. The way the model is setup in Blender is like so: Groups of objects that will be swapped (ex: Shoes -> Shoes objects) and an armature. I then export it to usdc with all objects active. This is the resulting hierarchy: Before exporting for the animation (armature modifier applied), I simply had to store the Model entities and swap them in but now when I export with the Armature Modifier applied, so that animations get exported, the ModelComponent gets flattened to the armature and swapping entities and applying new materials to them is no longer as simple. Here's a demo blend file and usdc export with a setup like mine, having an animated bone to swing a cube and sphere, to be swapped so that only one is visible https://www.dropbox.com/scl/fo/be2q6qcztc83z7c4gj1w0/AMapxWc_ip2KZ8oTOYDUMv8?rlkey=rcdaggcxq06dyen09mw5mqmem&st=bnc0d7j0&dl=0 This is how I'm loading the entity and removing a part, with the demo files import SwiftUI import RealityKit struct SwapDemoView: View { var body: some View { RealityView { content in let camera = PerspectiveCamera() camera.transform.translation = SIMD3(x: 0, y: 0.1, z: 3) guard let root = try? await Entity(named: "simpleSwapDemo") else { fatalError("simpleSwapDemo.usdc is not present") } print(root) // Get initial hierarchy guard let cube = root.findEntity(named: "Cube") else { fatalError("Entity cube doesn't exist") } cube.removeFromParent() // <-- Cube is still visible after removal print(root) // Get hierarchy to confirm removal of cube let resource = root.availableAnimations[0] root.playAnimation(resource.repeat()) content.add(root) content.add(camera) } .background(.white) } } And this is what the entity hierarchy looks like in RealityKit before cube removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 2 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity ⟐ SynchronizationComponent ⟐ Transform And here's the hierarchy after removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform And this is the result: What's the best practice here? Should animation be exported separately and then applied to the skeleton? If so, how is that achieved? I'm not really sure how to proceed here.
1
0
145
May ’25
ARView ignores multi-touch events
Hi, How to enable multitouch on ARView? Touch functions (touchesBegan, touchesMoved, ...) seem to only handle one touch at a time. In order to handle multiple touches at a time with ARView, I have to either: Use SwiftUI .simultaneousGesture on top of an ARView representable Position a UIView on top of ARView to capture touches and do hit testing by passing a reference to ARView Expected behavior: ARView should capture all touches via touchesBegan/Moved/Ended/Cancelled. Here is what I tried, on iOS 26.1 and macOS 26.1: ARView Multitouch The setup below is a minimal ARView presented by SwiftUI, with touch events handled inside ARView. Multitouch doesn't work with this setup. Note that multitouch wouldn't work either if the ARView is presented with a UIViewController instead of SwiftUI. import RealityKit import SwiftUI struct ARViewMultiTouchView: View { var body: some View { ZStack { ARViewMultiTouchRepresentable() .ignoresSafeArea() } } } #Preview { ARViewMultiTouchView() } // MARK: Representable ARView struct ARViewMultiTouchRepresentable: UIViewRepresentable { func makeUIView(context: Context) -> ARView { let arView = ARViewMultiTouch(frame: .zero) let anchor = AnchorEntity() arView.scene.addAnchor(anchor) let boxWidth: Float = 0.4 let boxMaterial = SimpleMaterial(color: .red, isMetallic: false) let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial]) box.name = "Box" box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)])) anchor.addChild(box) return arView } func updateUIView(_ uiView: ARView, context: Context) { } } // MARK: ARView class ARViewMultiTouch: ARView { required init(frame: CGRect) { super.init(frame: frame) /// Enable multi-touch isMultipleTouchEnabled = true cameraMode = .nonAR automaticallyConfigureSession = false environment.background = .color(.gray) /// Disable gesture recognizers to not conflict with touch events /// But it doesn't fix the issue gestureRecognizers?.forEach { $0.isEnabled = false } } required dynamic init?(coder decoder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { for touch in touches { /// # Problem /// This should print for every new touch, up to 5 simultaneously on an iPhone (multi-touch) /// But it only fires for one touch at a time (single-touch) print("Touch began at: \(touch.location(in: self))") } } } Multitouch with an Overlay This setup works, but it doesn't seem right. There must be a solution to make ARView handle multi touch directly, right? import SwiftUI import RealityKit struct MultiTouchOverlayView: View { var body: some View { ZStack { MultiTouchOverlayRepresentable() .ignoresSafeArea() Text("Multi touch with overlay view") .font(.system(size: 24, weight: .medium)) .foregroundStyle(.white) .offset(CGSize(width: 0, height: -150)) } } } #Preview { MultiTouchOverlayView() } // MARK: Representable Container struct MultiTouchOverlayRepresentable: UIViewRepresentable { func makeUIView(context: Context) -> UIView { /// The view that SwiftUI will present let container = UIView() /// ARView let arView = ARView(frame: container.bounds) arView.autoresizingMask = [.flexibleWidth, .flexibleHeight] arView.cameraMode = .nonAR arView.automaticallyConfigureSession = false arView.environment.background = .color(.gray) let anchor = AnchorEntity() arView.scene.addAnchor(anchor) let boxWidth: Float = 0.4 let boxMaterial = SimpleMaterial(color: .red, isMetallic: false) let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial]) box.name = "Box" box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)])) anchor.addChild(box) /// The view that will capture touches let touchOverlay = TouchOverlayView(frame: container.bounds) touchOverlay.autoresizingMask = [.flexibleWidth, .flexibleHeight] touchOverlay.backgroundColor = .clear /// Pass an arView reference to the overlay for hit testing touchOverlay.arView = arView /// Add views to the container. /// ARView goes in first, at the bottom. container.addSubview(arView) /// TouchOverlay goes in last, on top. container.addSubview(touchOverlay) return container } func updateUIView(_ uiView: UIView, context: Context) { } } // MARK: Touch Overlay View /// A UIView to handle multi-touch on top of ARView class TouchOverlayView: UIView { weak var arView: ARView? override init(frame: CGRect) { super.init(frame: frame) isMultipleTouchEnabled = true isUserInteractionEnabled = true } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { let totalTouches = event?.allTouches?.count ?? touches.count print("--- Touches Began --- (New: \(touches.count), Total: \(totalTouches))") for touch in touches { let location = touch.location(in: self) /// Hit testing. /// ARView and Touch View must be of the same size if let arView = arView { let entity = arView.entity(at: location) if let entity = entity { print("Touched entity: \(entity.name)") } else { print("Touched: none") } } } } override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) { let totalTouches = event?.allTouches?.count ?? touches.count print("--- Touches Cancelled --- (Cancelled: \(touches.count), Total: \(totalTouches))") } }
2
0
463
Jan ’26
authenticateHandler events not being received on iOS 18
I work on a team that provides an SDK for another game to handle various tasks like authentication. They are experiencing a case where devices using iOS 17 are failing to authenticate with GameCenter, receiving the message "The requested operation could not be completed because local player has not been authenticated." We imagine this is because they still have some setup to finish regarding GameCenter itself, and we're working with them to take care of that. However, on iOS 18, their app ends up waiting indefinitely for GameCenter authentication messages that it never receives. That's where we're puzzled. We expect them to have the same outcome regardless of OS version. We initiate GameCenter authentication by setting an authenticateHandler after some initial application setup. The handler has code to account for UI, errors, and successful authentication. On iOS 17, it's clear that it's getting called as expected because they receive an indication that the player isn't authenticated. But on iOS 18, it looks like the same handler code on iOS 18 isn't being called at all. Are there differences in how iOS 18 interacts with the authenticationHandler that we somehow aren't accounting for? Or is there potentially something else that we're doing incorrectly that is manifesting only on iOS 18? Here's a simplified version of our login function code (in Obj-C++). There is no OS-specific code, and the job that owns this function does stay in scope until after authentication is complete. void beginLogin() { // Snip: Check if the user is already logged in. // Snip: Prevent multiple concurrent calls to this function. auto authenticateHandler = ^(UIViewController* gcViewController, NSError* error) { if (gcViewController != nil) { // Snip: Display the UI } else if (error != nil) { // Snip: Handle the error. } else { if ([[GKLocalPlayer localPlayer] isAuthenticated]) { // Snip: Handle successful authentication. } else { // Snip: Handle other case. } } }; [[GKLocalPlayer localPlayer] setAuthenticateHandler: authenticateHandler]; }
2
0
188
May ’25
Particles rendered in the wrong order: back last instead of the back first
I've tried out a ParticleEmitter in Reality Composer Pro to produce a burst of particles that don't move (i.e. speed close to zero). When viewing from different angles, it clearly looks like the particles are rendered exactly in the wrong order, that is, front first and back last. In other words, back particles obscure front particles. I would prefer it the correct way around. I've only tried this interactively in Reality Composer Pro, not programmatically, but I assume I would get the same result. My Reality Composer Pro "File" (zipped): https://gert-rieger-edv.de/Posts/Post-1/RealityParticles.zip Screenshot: Click on the ParticleEmitter object, then on its Play button, then select the Particles tab and click on "Burst" a few times to get a few random particles. Mac Studio 2025 Apple M4 Max macOS 15.7.2 (24G325) Reality Composer Pro Version 2.0 (494.60.2)
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580
Dec ’25
Why does game mode not get triggered for my App?
I think I really have tried everything and I did all according to official documentation to support game mode on iOS or iPadOS but it doesn't matter what I do it just doesn't get triggered. Funny enough it works during development when I install it via Xcode but as soon as it is live on the store and when I install it from there game mode doesn't get triggered anymore. What I have atm I have added (even though it is deprecated) <key>GCSupportsGameMode</key> <true/> I have set the (but it seems only supported for macOS) <key>LSApplicationCategoryType</key> <string>public.app-category.games</string> I have added <key>LSSupportsGameMode</key> <true/> It just doesn't work. Is there anything else what needs to be done? Should the flag LSSupportsGameMode not be enough normally? The reason why this is so annoying is that my app is a real time streaming app and I want to profit from minimised background activities for smoother gameplay and more consistent frame rates like mentioned in the documentation.
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680
Nov ’25