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How to attach SwiftUI Views to entities on non-visionOS platforms?
What is the recommended way to attach SwiftUI views to RealityKit entities on macOS, iOS, etc? All the APIs seem to be visionOS only: https://developer.apple.com/documentation/realitykit/realityviewattachments https://developer.apple.com/documentation/realitykit/viewattachmentcomponent https://developer.apple.com/documentation/realitykit/presentationcomponent https://developer.apple.com/documentation/realitykit/imagepresentationcomponent My only idea is to do it "manually" with a ZStack and RealityView somehow? I submitted this as a feedback since it seemed like an oversight: FB18034856.
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170
Jun ’25
Memory leak when no draw calls issued to encoder
I noticed that when the render command encoder adds no draw calls an apps memory usage seems to grow unboundedly. Using a super simple MTKView-based drawing with the following delegate (code at end). If I add the simplest of draw calls, e.g., a single vertex, the app's memory usage is normal, around 100-ish MBs. I am attaching a couple screenshot, one from Xcode and one from Instruments. What's going on here? Is this an illegal program? If yes, why does it not crash, such as if the encode or command buffer weren't ended. Or is there some race condition at play here due to the lack of draws? class Renderer: NSObject, MTKViewDelegate { var device: MTLDevice var commandQueue: MTL4CommandQueue var commandBuffer: MTL4CommandBuffer var allocator: MTL4CommandAllocator override init() { guard let d = MTLCreateSystemDefaultDevice(), let queue = d.makeMTL4CommandQueue(), let cmdBuffer = d.makeCommandBuffer(), let alloc = d.makeCommandAllocator() else { fatalError("unable to create metal 4 objects") } self.device = d self.commandQueue = queue self.commandBuffer = cmdBuffer self.allocator = alloc super.init() } func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {} func draw(in view: MTKView) { guard let drawable = view.currentDrawable else { return } commandBuffer.beginCommandBuffer(allocator: allocator) guard let descriptor = view.currentMTL4RenderPassDescriptor, let encoder = commandBuffer.makeRenderCommandEncoder( descriptor: descriptor ) else { fatalError("unable to create encoder") } encoder.endEncoding() commandBuffer.endCommandBuffer() commandQueue.waitForDrawable(drawable) commandQueue.commit([commandBuffer]) commandQueue.signalDrawable(drawable) drawable.present() } }
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458
Jan ’26
Looking for some clarification
Was wondering if anyone from Apple could provide some clarification, The gaming studio "Epic Games" Is wondering if they could distribute the award winning game "Fortnite" back on MacOS without any retaliations. I know Fortnite being back on MacOS would benefit thousands of MacOS Devs. Hoping to get a clarification so Epic could start on bringing Fortnite back.
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862
Dec ’25
Per-vertex color. in a custom RealityKit mesh? (macOS)
I'm working on an application for viewing AMF models on macOS, using RealityKit. AMF supports several different ways to color models, including per-vertex color (where the color of a triangle is interpolated from vertex to vertex) as well as per-face color (where the color of the triangle is the same across the entire face). I'm trying to figure out how to support those color models using a RealityKit mesh. Apple's documentation (https://developer.apple.com/documentation/realitykit/modifying-realitykit-rendering-using-custom-materials) talks about per-vertex colors, but I haven't found a way to create a mesh that includes per-vertex colors, other than use a texture map (which might be the correct solution). Can someone give me some pointers?
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2.1k
Nov ’25
GestureComponent does not support DragGesture
The following code using the new GestureComponent demonstrates inconsistency. The tap gesture prints output, but the drag gesture does not. I already checked this post, which points to this seemingly outdated sample code I assume that example is deprecated in favour of the now built in version of GestureComponent. Nonetheless, there are no compiler warnings or errors, it just fails silently. TapGesture, LongPressGesture, MagnifyGesture, RotateGesture all work, so this feels like an oversight. RealityView { content in let testEntity = ModelEntity(mesh: .generateBox(size: .init(x: 1, y: 1, z: 1))) testEntity.position = SIMD3<Float>(0,0,-1) testEntity.components.set(InputTargetComponent()) testEntity.components.set(CollisionComponent( shapes: [.generateBox(size: .init(x: 1, y: 1, z: 1))] )) let testGesture = TapGesture() .onEnded { value in print("Tapped") } testEntity.components.set(GestureComponent(testGesture)) let dragGesture = DragGesture() .onEnded { value in print("Dragged") } testEntity.components.set(GestureComponent(dragGesture)) content.add(testEntity) }
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465
Jul ’25
Metal debug log in Swift Package
My goal is to print a debug message from a shader. I follow the guide that orders to set -fmetal-enable-logging metal compiler flag and following environment variables: MTL_LOG_LEVEL=MTLLogLevelDebug MTL_LOG_BUFFER_SIZE=2048 MTL_LOG_TO_STDERR=1 However there's an issue with the guide, it's only covers Xcode project setup, however I'm working on a Swift Package. It has a Metal-only target that's included into main target like this: targets: [ // A separate target for shaders. .target( name: "MetalShaders", resources: [ .process("Metal") ], plugins: [ // https://github.com/schwa/MetalCompilerPlugin .plugin(name: "MetalCompilerPlugin", package: "MetalCompilerPlugin") ] ), // Main target .target( name: "MegApp", dependencies: ["MetalShaders"] ), .testTarget( name: "MegAppTests", dependencies: [ "MegApp", "MetalShaders", ] ] So to apply compiler flag I use MetalCompilerPlugin which emits debug.metallib, it also allows to define DEBUG macro for shaders. This code compiles: #ifdef DEBUG logger.log_error("Hello There!"); os_log_default.log_debug("Hello thread: %d", gid); // this proves that code exectutes result.flag = true; #endif Environment is set via .xctestplan and valideted to work with ProcessInfo. However, nothing is printed to Xcode console nor to Console app. In attempt to fix it I'm trying to setup a MTLLogState, however the makeLogState(descriptor:) fails with error: if #available(iOS 18.0, *) { let logDescriptor = MTLLogStateDescriptor() logDescriptor.level = .debug logDescriptor.bufferSize = 2048 // Error Domain=MTLLogStateErrorDomain Code=2 "Cannot create residency set for MTLLogState: (null)" UserInfo={NSLocalizedDescription=Cannot create residency set for MTLLogState: (null)} let logState = try! device.makeLogState(descriptor: logDescriptor) commandBufferDescriptor.logState = logState } Some LLMs suggested that this is connected with Simulator, and truly, I run the tests on simulator. However tests don't want to run on iPhone... I found solution running them on My Mac (Mac Catalyst). Surprisingly descriptor log works there, even without MTLLogState. But the Simulator behaviour seems like a bug...
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786
Jan ’26
Inexplicable Metal crash ever since iOS 26.5 beta 4
Hi all, I'm working on updating my audio visualizer app. I'm adding new visualizers based on Metal 4 compute shaders. They worked in iOS 26.4 and iOS 26.5 up until beta 3. However, after that, the visualizers started crashing the phone and forcing a restart. On the latest version of iOS 26.5, the crash is still there. I submitted feedback, but haven't heard anything back just yet. I was wondering if others have faced this same issue, and if there are any workarounds. Here is my repo if you want to look at the code (forgive me if it's sloppy, I'm quite new to graphics programming and Metal): https://github.com/aabagdi/VisualMan/tree/main Thank you!
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1d
GameKit not working as expected in iOS 26.
I just upgraded my macOS, Xcode and Simulator all to the newest beta version 26. Then I found two issues when building my app with Xcode 26 and running it on simulator 26. The game center access point no longer shows up in the app. This is how it's configured in the past. And it still works on simulator 18.4 func authenticatePlayer() { GKAccessPoint.shared.location = .topTrailing self.localPlayer.authenticateHandler = { viewController, error in if let viewController = viewController { // can present Game Center login screen } else if self.localPlayer.isAuthenticated { // game can be started } else { // user didn't log in, continue the game without game center } } } After game ended, the leaderboard won't load. This is how it's implemented in the past. It's still working in simulator 18.4 struct GameCenterView: UIViewControllerRepresentable { @Environment(\.presentationMode) var presentationMode ... func makeUIViewController(context: Context) -> GKGameCenterViewController { let viewController = GKGameCenterViewController( leaderboardID: getLeaderBoardID(with: leaderBoardGameMode), playerScope: .global, timeScope: .allTime ) viewController.gameCenterDelegate = context.coordinator return viewController } func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {} func makeCoordinator() -> Coordinator { Coordinator(self) } class Coordinator: NSObject, GKGameCenterControllerDelegate { let parent: GameCenterView init(_ parent: GameCenterView) { self.parent = parent } func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) { parent.presentationMode.wrappedValue.dismiss() } } }
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546
Sep ’25
Spatial Scene API for iOS Apps
As part of the WWDC25 Keynote, a technology was announced that can present 2D images as 3D spatial scenes. This announcement is supported by a Press Release. ...developers can use the Spatial Scene API to make their app experience even more immersive. Zillow is taking advantage of the API for their Zillow Immersive app, allowing users to see images of homes and apartments with the rich depth and dimension that spatial scenes offer. The feature also appears in the Photos App on iOS 26 Developer Beta 1. Tapping "Spatial Scene" on any photo opens a view of that photo with a parallax effect. I've searched the WWDC sessions and new documentation and have come up short. Reaching out here for help. Is there any documentation for Spatial Scene API? Or any guidance on how to implement the spatial scene in iOS?
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405
Jun ’25
Does VisionOS have the equivalent of ARView.physicsOrigin?
I'm trying to scale the physics of a scene without changing the apparent size to avoid the low-speed zeroing-out of motion that the physics simulation does. I found a technique for using separate simulation and physics roots in the docs, but it relies on ARView, which VisionOS doesn't have. This seems more elegant than scaling absolutely everything with shared root -- any chance I'm just failing in my searches to find the equivalent functionality?
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821
Mar ’26
Skybox for iOS/swiftUI not working
I have tried every combination of suggestions to get a skybox to appear. Using swiftUI, realityKit and iOS. Non immersive environment. Does anyone have code that works to display a skybox. When i use a do/catch loop i get environmentResource not found. I have checked the syntax, ensured the folder is referencing the target, used the same name for the folder as the file, the file is a .hdr (i assume this is supported), i have moved the file folder to the top level - no change.
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644
Dec ’25
virtual game controller + SwiftUI warning
Hi, I've just moved my SpriteKit-based game from UIView to SwiftUI + SpriteView and I'm getting this mesage Adding 'GCControllerView' as a subview of UIHostingController.view is not supported and may result in a broken view hierarchy. Add your view above UIHostingController.view in a common superview or insert it into your SwiftUI content in a UIViewRepresentable instead. Here's how I'm doing this struct ContentView: View { @State var alreadyStarted = false let initialScene = GKScene(fileNamed: "StartScene")!.rootNode as! SKScene var body: some View { ZStack { SpriteView(scene: initialScene, transition: .crossFade(withDuration: 1), isPaused: false , preferredFramesPerSecond: 60) .edgesIgnoringSafeArea(.all) .onAppear { if !self.alreadyStarted { self.alreadyStarted.toggle() initialScene.scaleMode = .aspectFit } } VirtualControllerView() .onAppear { let virtualController = BTTSUtilities.shared.makeVirtualController() BTTSSharedData.shared.virtualGameController = virtualController BTTSSharedData.shared.virtualGameController?.connect() } .onDisappear { BTTSSharedData.shared.virtualGameController?.disconnect() } } } } struct VirtualControllerView: UIViewRepresentable { func makeUIView(context: Context) -> UIView { let result = PassthroughView() return result } func updateUIView(_ uiView: UIView, context: Context) { } } class PassthroughView: UIView { override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? { for subview in subviews.reversed() { let convertedPoint = convert(point, to: subview) if let hitView = subview.hitTest(convertedPoint, with: event) { return hitView } } return nil } }
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648
Sep ’25
PSVR2 controllers don't report anything in snapshot
I typically read an extended gamepad capture() and get all state. But PSVR2 controllers seem to report nothing. So the stick and other buttons don't do anything in a built app. They register as left/right controllers. This on vOS 26, Xcode 26, etc. They work correctly in the main icon view, although they don't honor inverted vertical and horiztonal scrolling. Both of the default scrolls just feel wrong. When I move left I'm want to scroll level not right. Same for up/down.
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938
Sep ’25
Metal: Intersection results unstable when reusing Instance Acceleration Structures
Hi all, I'm encountering an issue with Metal raytracing on my M5 MacBook Pro regarding Instance Acceleration Structure (IAS). Intersection tests suddenly stop working after a certain point in the sampling loop. Situation I implemented an offline GPU path tracer that runs the same kernel multiple times per pixel (sampleCount) using metal::raytracing. Intersection tests are performed using an IAS. Since this is an offline path tracer, geometries inside the IAS never changes across samples (no transforms or updates). As sampleCount increases, there comes a point where the number of intersections drops to zero, and remains zero for all subsequent samples. Here's a code sketch: let sampleCount: UInt16 = 1024 for sampleIndex: UInt16 in 0..<sampleCount { // ... do { let commandBuffer = commandQueue.makeCommandBuffer() // Dispatch the intersection kernel. await commandBuffer.completed() } do { let commandBuffer = commandQueue.makeCommandBuffer() // Use the intersection test results from the previous command buffer. await commandBuffer.completed() } // ... } kernel void intersectAlongRay( const metal::uint32_t threadIndex [[thread_position_in_grid]], // ... const metal::raytracing::instance_acceleration_structure accelerationStructure [[buffer(2)]], // ... ) { // ... const auto result = intersector.intersect(ray, accelerationStructure); switch (result.type) { case metal::raytracing::intersection_type::triangle: { // Write intersection result to device buffers. break; } default: break; } Observations Encoding both the intersection kernel and the subsequent result usage in the same command buffer does not resolve the problem. Switching from IAS to Primitive Acceleration Structure (PAS) fixes the problem. Rebuilding the IAS for each sample also resolves the issue. Intersections produce inconsistent results even though the IAS and rays are identical — Image 1 shows a hit, while Image 2 shows a miss. Questions Am I misusing IAS in some way ? Could this be a Metal bug ? Any guidance or confirmation would be greatly appreciated.
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Dec ’25
ParticleEmitterComponent Position Offset Issue After iOS 26.1 Update – Seeking Solutions & Workarounds
Problem Summary After upgrading to iOS 26.1 and 26.2, I'm experiencing a particle positioning bug in RealityKit where ParticleEmitterComponent particles render at an incorrect offset relative to their parent entity. This behavior does not occur on iOS 18.6.2 or earlier versions, suggesting a regression introduced in the newer OS builds. Environment Details Operating System: iOS 26.1 & iOS 26.2 Framework: RealityKit Xcode Version: 16.2 (16C5032a) Expected vs. Actual Behavior Expected: Particles should render at the position of the entity to which the ParticleEmitterComponent is attached, matching the behavior on iOS 18.6.2 and earlier. Actual: Particles appear away from their parent entity, creating a visual misalignment that breaks the intended AR experience. Steps to Reproduce Create or open an AR application with RealityKit that uses particle components Attach a ParticleEmitterComponent to an entity via a custom system Run the application on iOS 26.1 or iOS 26.2 Observe that particles render at an offset position away from the entity Minimal Code Example Here's the setup from my test case: Custom Component & System: struct SparkleComponent4: Component {} class SparkleSystem4: System { static let query = EntityQuery(where: .has(SparkleComponent4.self)) required init(scene: Scene) {} func update(context: SceneUpdateContext) { for entity in context.scene.performQuery(Self.query) { // Only add once if entity.components.has(ParticleEmitterComponent.self) { continue } var newEmitter = ParticleEmitterComponent() newEmitter.mainEmitter.color = .constant(.single(.red)) entity.components.set(newEmitter) } } } AR Setup: let material = SimpleMaterial(color: .gray, roughness: 0.15, isMetallic: true) let model = Entity() model.components.set(ModelComponent(mesh: boxMesh, materials: [material])) model.components.set(SparkleComponent4()) model.position = [0, 0.05, 0] model.name = "MyCube" let anchor = AnchorEntity(.plane(.horizontal, classification: .any, minimumBounds: [0.2, 0.2])) anchor.addChild(model) arView.scene.addAnchor(anchor) Questions for the Community Has anyone else encountered this particle positioning issue after updating to iOS 26.1/26.2? Are there known workarounds or configuration changes to ParticleEmitterComponent that restore correct positioning? Is this a confirmed bug, or could there be a change in coordinate system handling or transform inheritance that I'm missing? Additional Information I've already submitted this issue via Feedback Assistant(FB21346746)
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1.1k
Apr ’26
How to use MetalPeformancePrimitives
I am trying to learn the new Metal Peformance Primitives APIs. I have added the MetalPeformancePrimitives framework and included the header in my shader code as per documentation #include <MetalPeformancePrimitives/MetalPeformancePrimitives.h> Unfortunately, Xcode complains that the header cannot be found. How do I include it properly? I am using Xcode 26 on Tahoe. The MetalPeformancePrimitives framework is present on my machine and I can inspect the headers in the filesystem.
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814
Oct ’25
Game Center challenges and activities issues for released game
We have a released game in the App Store with Game Center Challenges. The challenges were working well in testing of the final version before the Game Center challenges went live. After release the activity that should take the player to the challenge in game results in this printout and we do not get informed by GKGameActivityListener of the activity happening in our code as we did before the Game Center challenges went live. “Invalid game activity definition. Failed to kick activity notification to GameKit. Error: Error Domain=GKErrorDomain Code=17 "(null)"” Also, Game Center reports that the are no challenges in GKChallengeDefinition.all even though there are ongoing challenges. The leaderboard results do get reported to Game Center though and show up as challenge entries in the Games app. At the moment we are trying to figure out if this is a problem on our end or a Game Center server issue.
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704
Sep ’25
RealityView AR - anchored to the screen not the floor
This started out as a plea for help, but in preparing this post I discovered the root cause. I'm posting it as a lesson learned in hopes it will help someone. I've spent a good chunk of March trying to get AR-mode working again in my unreleased game. I had it working with SceneKit and ARView 5 years ago, but since 2024 I've been converting the game to use RealityKit and RealityView on iOS, macOS, visionOS, and tvOS. I've been having no joy getting AR mode to work on iOS. I get the pass-through device video but the game content isn't anchored to the floor but rather anchored to the screen. I made a simple project with just a simple shape in the middle of a RealityView and an overlay with a SwiftUI toggle to go in and out of AR-mode. At first, my simple project worked, and I couldn't figure out what was different in the logic. Both projects used the same logic: func transitionToXR(_ content: inout RealityViewCameraContent) { content.remove(gameBoard.rootEntity) content.add(xrAnchor) content.camera = .spatialTracking Self.anchorStateChangedSubscription = content.subscribe(to: SceneEvents.AnchoredStateChanged.self) { event in if event.anchor == xrAnchor, event.isAnchored { xrAnchor.addChild(gameBoard.rootEntity) } } } Then I made an alternate version of my view, and reproduced the same "anchored to the screen not the floor" issue. I compared the code side-by-side and finally saw the difference! The one that didn't work, like my game, had a property 'cameraEntity' which is initialized with PerspectiveCamera(), position and look-at configured, then added as a child of the root entity. So, the simple fix was to remove 'cameraEntity' from the root entity before adding it to the detected AnchorEntity when going into AR-mode. Then when leaving AR-mode, I add back 'cameraEntity' as a child of the root entity and configure it again. So the lesson learned is: make sure there isn't a PerspectiveCamera in the tree of Entities added to an AnchorEntity with a .spatialTracking content camera. Apple: let me know if you think this is a bug or if I was being dumb. If a bug, I can use Feedback Assistant to report this. If I was being dumb, it wouldn't be the first time. :-)
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1w
Can Apple please add Nintendo Switch 2 Pro Controller support? This is a very popular controller.
Hi Apple, Can you please add support for the Nintendo Switch 2 Pro Controller? The first one is supported but the Switch 2 has been out nearly a year now and a lot of people want to use these controllers with macOS and iOS. Can you please consider adding support? Thank you.
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1
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0
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554
Activity
Apr ’26
What's wrong with simd_inverse?
When using simd_inverse functions, the same input yields different results on different devices. On the Mac mini with M4 pro and M3 ultra, the result is But on the Mac mini of M2 ultra, the result is
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2
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0
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1.1k
Activity
Aug ’25
How to attach SwiftUI Views to entities on non-visionOS platforms?
What is the recommended way to attach SwiftUI views to RealityKit entities on macOS, iOS, etc? All the APIs seem to be visionOS only: https://developer.apple.com/documentation/realitykit/realityviewattachments https://developer.apple.com/documentation/realitykit/viewattachmentcomponent https://developer.apple.com/documentation/realitykit/presentationcomponent https://developer.apple.com/documentation/realitykit/imagepresentationcomponent My only idea is to do it "manually" with a ZStack and RealityView somehow? I submitted this as a feedback since it seemed like an oversight: FB18034856.
Replies
0
Boosts
2
Views
170
Activity
Jun ’25
Memory leak when no draw calls issued to encoder
I noticed that when the render command encoder adds no draw calls an apps memory usage seems to grow unboundedly. Using a super simple MTKView-based drawing with the following delegate (code at end). If I add the simplest of draw calls, e.g., a single vertex, the app's memory usage is normal, around 100-ish MBs. I am attaching a couple screenshot, one from Xcode and one from Instruments. What's going on here? Is this an illegal program? If yes, why does it not crash, such as if the encode or command buffer weren't ended. Or is there some race condition at play here due to the lack of draws? class Renderer: NSObject, MTKViewDelegate { var device: MTLDevice var commandQueue: MTL4CommandQueue var commandBuffer: MTL4CommandBuffer var allocator: MTL4CommandAllocator override init() { guard let d = MTLCreateSystemDefaultDevice(), let queue = d.makeMTL4CommandQueue(), let cmdBuffer = d.makeCommandBuffer(), let alloc = d.makeCommandAllocator() else { fatalError("unable to create metal 4 objects") } self.device = d self.commandQueue = queue self.commandBuffer = cmdBuffer self.allocator = alloc super.init() } func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {} func draw(in view: MTKView) { guard let drawable = view.currentDrawable else { return } commandBuffer.beginCommandBuffer(allocator: allocator) guard let descriptor = view.currentMTL4RenderPassDescriptor, let encoder = commandBuffer.makeRenderCommandEncoder( descriptor: descriptor ) else { fatalError("unable to create encoder") } encoder.endEncoding() commandBuffer.endCommandBuffer() commandQueue.waitForDrawable(drawable) commandQueue.commit([commandBuffer]) commandQueue.signalDrawable(drawable) drawable.present() } }
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3
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0
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458
Activity
Jan ’26
Looking for some clarification
Was wondering if anyone from Apple could provide some clarification, The gaming studio "Epic Games" Is wondering if they could distribute the award winning game "Fortnite" back on MacOS without any retaliations. I know Fortnite being back on MacOS would benefit thousands of MacOS Devs. Hoping to get a clarification so Epic could start on bringing Fortnite back.
Replies
0
Boosts
2
Views
862
Activity
Dec ’25
Per-vertex color. in a custom RealityKit mesh? (macOS)
I'm working on an application for viewing AMF models on macOS, using RealityKit. AMF supports several different ways to color models, including per-vertex color (where the color of a triangle is interpolated from vertex to vertex) as well as per-face color (where the color of the triangle is the same across the entire face). I'm trying to figure out how to support those color models using a RealityKit mesh. Apple's documentation (https://developer.apple.com/documentation/realitykit/modifying-realitykit-rendering-using-custom-materials) talks about per-vertex colors, but I haven't found a way to create a mesh that includes per-vertex colors, other than use a texture map (which might be the correct solution). Can someone give me some pointers?
Replies
6
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2
Views
2.1k
Activity
Nov ’25
GestureComponent does not support DragGesture
The following code using the new GestureComponent demonstrates inconsistency. The tap gesture prints output, but the drag gesture does not. I already checked this post, which points to this seemingly outdated sample code I assume that example is deprecated in favour of the now built in version of GestureComponent. Nonetheless, there are no compiler warnings or errors, it just fails silently. TapGesture, LongPressGesture, MagnifyGesture, RotateGesture all work, so this feels like an oversight. RealityView { content in let testEntity = ModelEntity(mesh: .generateBox(size: .init(x: 1, y: 1, z: 1))) testEntity.position = SIMD3<Float>(0,0,-1) testEntity.components.set(InputTargetComponent()) testEntity.components.set(CollisionComponent( shapes: [.generateBox(size: .init(x: 1, y: 1, z: 1))] )) let testGesture = TapGesture() .onEnded { value in print("Tapped") } testEntity.components.set(GestureComponent(testGesture)) let dragGesture = DragGesture() .onEnded { value in print("Dragged") } testEntity.components.set(GestureComponent(dragGesture)) content.add(testEntity) }
Replies
3
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1
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465
Activity
Jul ’25
Metal debug log in Swift Package
My goal is to print a debug message from a shader. I follow the guide that orders to set -fmetal-enable-logging metal compiler flag and following environment variables: MTL_LOG_LEVEL=MTLLogLevelDebug MTL_LOG_BUFFER_SIZE=2048 MTL_LOG_TO_STDERR=1 However there's an issue with the guide, it's only covers Xcode project setup, however I'm working on a Swift Package. It has a Metal-only target that's included into main target like this: targets: [ // A separate target for shaders. .target( name: "MetalShaders", resources: [ .process("Metal") ], plugins: [ // https://github.com/schwa/MetalCompilerPlugin .plugin(name: "MetalCompilerPlugin", package: "MetalCompilerPlugin") ] ), // Main target .target( name: "MegApp", dependencies: ["MetalShaders"] ), .testTarget( name: "MegAppTests", dependencies: [ "MegApp", "MetalShaders", ] ] So to apply compiler flag I use MetalCompilerPlugin which emits debug.metallib, it also allows to define DEBUG macro for shaders. This code compiles: #ifdef DEBUG logger.log_error("Hello There!"); os_log_default.log_debug("Hello thread: %d", gid); // this proves that code exectutes result.flag = true; #endif Environment is set via .xctestplan and valideted to work with ProcessInfo. However, nothing is printed to Xcode console nor to Console app. In attempt to fix it I'm trying to setup a MTLLogState, however the makeLogState(descriptor:) fails with error: if #available(iOS 18.0, *) { let logDescriptor = MTLLogStateDescriptor() logDescriptor.level = .debug logDescriptor.bufferSize = 2048 // Error Domain=MTLLogStateErrorDomain Code=2 "Cannot create residency set for MTLLogState: (null)" UserInfo={NSLocalizedDescription=Cannot create residency set for MTLLogState: (null)} let logState = try! device.makeLogState(descriptor: logDescriptor) commandBufferDescriptor.logState = logState } Some LLMs suggested that this is connected with Simulator, and truly, I run the tests on simulator. However tests don't want to run on iPhone... I found solution running them on My Mac (Mac Catalyst). Surprisingly descriptor log works there, even without MTLLogState. But the Simulator behaviour seems like a bug...
Replies
1
Boosts
1
Views
786
Activity
Jan ’26
Inexplicable Metal crash ever since iOS 26.5 beta 4
Hi all, I'm working on updating my audio visualizer app. I'm adding new visualizers based on Metal 4 compute shaders. They worked in iOS 26.4 and iOS 26.5 up until beta 3. However, after that, the visualizers started crashing the phone and forcing a restart. On the latest version of iOS 26.5, the crash is still there. I submitted feedback, but haven't heard anything back just yet. I was wondering if others have faced this same issue, and if there are any workarounds. Here is my repo if you want to look at the code (forgive me if it's sloppy, I'm quite new to graphics programming and Metal): https://github.com/aabagdi/VisualMan/tree/main Thank you!
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4
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663
Activity
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GameKit not working as expected in iOS 26.
I just upgraded my macOS, Xcode and Simulator all to the newest beta version 26. Then I found two issues when building my app with Xcode 26 and running it on simulator 26. The game center access point no longer shows up in the app. This is how it's configured in the past. And it still works on simulator 18.4 func authenticatePlayer() { GKAccessPoint.shared.location = .topTrailing self.localPlayer.authenticateHandler = { viewController, error in if let viewController = viewController { // can present Game Center login screen } else if self.localPlayer.isAuthenticated { // game can be started } else { // user didn't log in, continue the game without game center } } } After game ended, the leaderboard won't load. This is how it's implemented in the past. It's still working in simulator 18.4 struct GameCenterView: UIViewControllerRepresentable { @Environment(\.presentationMode) var presentationMode ... func makeUIViewController(context: Context) -> GKGameCenterViewController { let viewController = GKGameCenterViewController( leaderboardID: getLeaderBoardID(with: leaderBoardGameMode), playerScope: .global, timeScope: .allTime ) viewController.gameCenterDelegate = context.coordinator return viewController } func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {} func makeCoordinator() -> Coordinator { Coordinator(self) } class Coordinator: NSObject, GKGameCenterControllerDelegate { let parent: GameCenterView init(_ parent: GameCenterView) { self.parent = parent } func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) { parent.presentationMode.wrappedValue.dismiss() } } }
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5
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546
Activity
Sep ’25
Spatial Scene API for iOS Apps
As part of the WWDC25 Keynote, a technology was announced that can present 2D images as 3D spatial scenes. This announcement is supported by a Press Release. ...developers can use the Spatial Scene API to make their app experience even more immersive. Zillow is taking advantage of the API for their Zillow Immersive app, allowing users to see images of homes and apartments with the rich depth and dimension that spatial scenes offer. The feature also appears in the Photos App on iOS 26 Developer Beta 1. Tapping "Spatial Scene" on any photo opens a view of that photo with a parallax effect. I've searched the WWDC sessions and new documentation and have come up short. Reaching out here for help. Is there any documentation for Spatial Scene API? Or any guidance on how to implement the spatial scene in iOS?
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405
Activity
Jun ’25
Does VisionOS have the equivalent of ARView.physicsOrigin?
I'm trying to scale the physics of a scene without changing the apparent size to avoid the low-speed zeroing-out of motion that the physics simulation does. I found a technique for using separate simulation and physics roots in the docs, but it relies on ARView, which VisionOS doesn't have. This seems more elegant than scaling absolutely everything with shared root -- any chance I'm just failing in my searches to find the equivalent functionality?
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3
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821
Activity
Mar ’26
Skybox for iOS/swiftUI not working
I have tried every combination of suggestions to get a skybox to appear. Using swiftUI, realityKit and iOS. Non immersive environment. Does anyone have code that works to display a skybox. When i use a do/catch loop i get environmentResource not found. I have checked the syntax, ensured the folder is referencing the target, used the same name for the folder as the file, the file is a .hdr (i assume this is supported), i have moved the file folder to the top level - no change.
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644
Activity
Dec ’25
virtual game controller + SwiftUI warning
Hi, I've just moved my SpriteKit-based game from UIView to SwiftUI + SpriteView and I'm getting this mesage Adding 'GCControllerView' as a subview of UIHostingController.view is not supported and may result in a broken view hierarchy. Add your view above UIHostingController.view in a common superview or insert it into your SwiftUI content in a UIViewRepresentable instead. Here's how I'm doing this struct ContentView: View { @State var alreadyStarted = false let initialScene = GKScene(fileNamed: "StartScene")!.rootNode as! SKScene var body: some View { ZStack { SpriteView(scene: initialScene, transition: .crossFade(withDuration: 1), isPaused: false , preferredFramesPerSecond: 60) .edgesIgnoringSafeArea(.all) .onAppear { if !self.alreadyStarted { self.alreadyStarted.toggle() initialScene.scaleMode = .aspectFit } } VirtualControllerView() .onAppear { let virtualController = BTTSUtilities.shared.makeVirtualController() BTTSSharedData.shared.virtualGameController = virtualController BTTSSharedData.shared.virtualGameController?.connect() } .onDisappear { BTTSSharedData.shared.virtualGameController?.disconnect() } } } } struct VirtualControllerView: UIViewRepresentable { func makeUIView(context: Context) -> UIView { let result = PassthroughView() return result } func updateUIView(_ uiView: UIView, context: Context) { } } class PassthroughView: UIView { override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? { for subview in subviews.reversed() { let convertedPoint = convert(point, to: subview) if let hitView = subview.hitTest(convertedPoint, with: event) { return hitView } } return nil } }
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648
Activity
Sep ’25
PSVR2 controllers don't report anything in snapshot
I typically read an extended gamepad capture() and get all state. But PSVR2 controllers seem to report nothing. So the stick and other buttons don't do anything in a built app. They register as left/right controllers. This on vOS 26, Xcode 26, etc. They work correctly in the main icon view, although they don't honor inverted vertical and horiztonal scrolling. Both of the default scrolls just feel wrong. When I move left I'm want to scroll level not right. Same for up/down.
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938
Activity
Sep ’25
Metal: Intersection results unstable when reusing Instance Acceleration Structures
Hi all, I'm encountering an issue with Metal raytracing on my M5 MacBook Pro regarding Instance Acceleration Structure (IAS). Intersection tests suddenly stop working after a certain point in the sampling loop. Situation I implemented an offline GPU path tracer that runs the same kernel multiple times per pixel (sampleCount) using metal::raytracing. Intersection tests are performed using an IAS. Since this is an offline path tracer, geometries inside the IAS never changes across samples (no transforms or updates). As sampleCount increases, there comes a point where the number of intersections drops to zero, and remains zero for all subsequent samples. Here's a code sketch: let sampleCount: UInt16 = 1024 for sampleIndex: UInt16 in 0..<sampleCount { // ... do { let commandBuffer = commandQueue.makeCommandBuffer() // Dispatch the intersection kernel. await commandBuffer.completed() } do { let commandBuffer = commandQueue.makeCommandBuffer() // Use the intersection test results from the previous command buffer. await commandBuffer.completed() } // ... } kernel void intersectAlongRay( const metal::uint32_t threadIndex [[thread_position_in_grid]], // ... const metal::raytracing::instance_acceleration_structure accelerationStructure [[buffer(2)]], // ... ) { // ... const auto result = intersector.intersect(ray, accelerationStructure); switch (result.type) { case metal::raytracing::intersection_type::triangle: { // Write intersection result to device buffers. break; } default: break; } Observations Encoding both the intersection kernel and the subsequent result usage in the same command buffer does not resolve the problem. Switching from IAS to Primitive Acceleration Structure (PAS) fixes the problem. Rebuilding the IAS for each sample also resolves the issue. Intersections produce inconsistent results even though the IAS and rays are identical — Image 1 shows a hit, while Image 2 shows a miss. Questions Am I misusing IAS in some way ? Could this be a Metal bug ? Any guidance or confirmation would be greatly appreciated.
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371
Activity
Dec ’25
ParticleEmitterComponent Position Offset Issue After iOS 26.1 Update – Seeking Solutions & Workarounds
Problem Summary After upgrading to iOS 26.1 and 26.2, I'm experiencing a particle positioning bug in RealityKit where ParticleEmitterComponent particles render at an incorrect offset relative to their parent entity. This behavior does not occur on iOS 18.6.2 or earlier versions, suggesting a regression introduced in the newer OS builds. Environment Details Operating System: iOS 26.1 & iOS 26.2 Framework: RealityKit Xcode Version: 16.2 (16C5032a) Expected vs. Actual Behavior Expected: Particles should render at the position of the entity to which the ParticleEmitterComponent is attached, matching the behavior on iOS 18.6.2 and earlier. Actual: Particles appear away from their parent entity, creating a visual misalignment that breaks the intended AR experience. Steps to Reproduce Create or open an AR application with RealityKit that uses particle components Attach a ParticleEmitterComponent to an entity via a custom system Run the application on iOS 26.1 or iOS 26.2 Observe that particles render at an offset position away from the entity Minimal Code Example Here's the setup from my test case: Custom Component & System: struct SparkleComponent4: Component {} class SparkleSystem4: System { static let query = EntityQuery(where: .has(SparkleComponent4.self)) required init(scene: Scene) {} func update(context: SceneUpdateContext) { for entity in context.scene.performQuery(Self.query) { // Only add once if entity.components.has(ParticleEmitterComponent.self) { continue } var newEmitter = ParticleEmitterComponent() newEmitter.mainEmitter.color = .constant(.single(.red)) entity.components.set(newEmitter) } } } AR Setup: let material = SimpleMaterial(color: .gray, roughness: 0.15, isMetallic: true) let model = Entity() model.components.set(ModelComponent(mesh: boxMesh, materials: [material])) model.components.set(SparkleComponent4()) model.position = [0, 0.05, 0] model.name = "MyCube" let anchor = AnchorEntity(.plane(.horizontal, classification: .any, minimumBounds: [0.2, 0.2])) anchor.addChild(model) arView.scene.addAnchor(anchor) Questions for the Community Has anyone else encountered this particle positioning issue after updating to iOS 26.1/26.2? Are there known workarounds or configuration changes to ParticleEmitterComponent that restore correct positioning? Is this a confirmed bug, or could there be a change in coordinate system handling or transform inheritance that I'm missing? Additional Information I've already submitted this issue via Feedback Assistant(FB21346746)
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1.1k
Activity
Apr ’26
How to use MetalPeformancePrimitives
I am trying to learn the new Metal Peformance Primitives APIs. I have added the MetalPeformancePrimitives framework and included the header in my shader code as per documentation #include <MetalPeformancePrimitives/MetalPeformancePrimitives.h> Unfortunately, Xcode complains that the header cannot be found. How do I include it properly? I am using Xcode 26 on Tahoe. The MetalPeformancePrimitives framework is present on my machine and I can inspect the headers in the filesystem.
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3
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814
Activity
Oct ’25
Game Center challenges and activities issues for released game
We have a released game in the App Store with Game Center Challenges. The challenges were working well in testing of the final version before the Game Center challenges went live. After release the activity that should take the player to the challenge in game results in this printout and we do not get informed by GKGameActivityListener of the activity happening in our code as we did before the Game Center challenges went live. “Invalid game activity definition. Failed to kick activity notification to GameKit. Error: Error Domain=GKErrorDomain Code=17 "(null)"” Also, Game Center reports that the are no challenges in GKChallengeDefinition.all even though there are ongoing challenges. The leaderboard results do get reported to Game Center though and show up as challenge entries in the Games app. At the moment we are trying to figure out if this is a problem on our end or a Game Center server issue.
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4
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704
Activity
Sep ’25
RealityView AR - anchored to the screen not the floor
This started out as a plea for help, but in preparing this post I discovered the root cause. I'm posting it as a lesson learned in hopes it will help someone. I've spent a good chunk of March trying to get AR-mode working again in my unreleased game. I had it working with SceneKit and ARView 5 years ago, but since 2024 I've been converting the game to use RealityKit and RealityView on iOS, macOS, visionOS, and tvOS. I've been having no joy getting AR mode to work on iOS. I get the pass-through device video but the game content isn't anchored to the floor but rather anchored to the screen. I made a simple project with just a simple shape in the middle of a RealityView and an overlay with a SwiftUI toggle to go in and out of AR-mode. At first, my simple project worked, and I couldn't figure out what was different in the logic. Both projects used the same logic: func transitionToXR(_ content: inout RealityViewCameraContent) { content.remove(gameBoard.rootEntity) content.add(xrAnchor) content.camera = .spatialTracking Self.anchorStateChangedSubscription = content.subscribe(to: SceneEvents.AnchoredStateChanged.self) { event in if event.anchor == xrAnchor, event.isAnchored { xrAnchor.addChild(gameBoard.rootEntity) } } } Then I made an alternate version of my view, and reproduced the same "anchored to the screen not the floor" issue. I compared the code side-by-side and finally saw the difference! The one that didn't work, like my game, had a property 'cameraEntity' which is initialized with PerspectiveCamera(), position and look-at configured, then added as a child of the root entity. So, the simple fix was to remove 'cameraEntity' from the root entity before adding it to the detected AnchorEntity when going into AR-mode. Then when leaving AR-mode, I add back 'cameraEntity' as a child of the root entity and configure it again. So the lesson learned is: make sure there isn't a PerspectiveCamera in the tree of Entities added to an AnchorEntity with a .spatialTracking content camera. Apple: let me know if you think this is a bug or if I was being dumb. If a bug, I can use Feedback Assistant to report this. If I was being dumb, it wouldn't be the first time. :-)
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