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...

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() }

I'm developing a turn based game. When I present the GKTurnBasedMatchmakerViewController players can opt in for automatch instead of selecting a specific friend as opponent. How exactly does the matching work if a player doesn't specify anything explicitly? Does Game Center send push notifications in a round robin fashion to all friends and the first one to accept is then matched as opponent? Is this documented somewhere?

I noticed that MTLPixelFormat has this cases: case r32Float = 55 case rg32Float = 105 case rgba32Float = 125 But no case rgb32Float. What's the reason for such a discrimination?

I'm developing a game that supports GameKit turn based matches. What I don't understand is this: Is tapping on the Game Center notification push messages the only way for the GKTurnBasedEventListener to trigger? What if someone misses the push message (swiping it away by accident or something like that) but still wants to join? Is there some inbox somewhere where the pending messages can be seen or fetched? Also it was mentioned in a very old WWDC video (from 2013, I think that's the latest with information about turn based matches) that the notification also includes a badge for the icon. However, I do not understand how to implement that. Is there any documentation for that?

Hi, I would like clarification on whether the new hover effects feature introduced in vision os 26 supported pinch gestures through the psvr 2 controllers. In your sample application, I was not able to confirm that this was working. Only pinch clicking with my hands worked. Pulling the trigger on the controller whilst looking at a 3d object did not activate the hover effect spatial event in the sample application. (The object is showing the highlight though) This is inconsistent with hover effect behavior with psvr2 controllers on swift ui views, where the trigger press does count as a button click. The sample I used was this one: https://developer.apple.com/documentation/compositorservices/rendering_hover_effects_in_metal_immersive_apps

In my game 854159268 (com.1791entertainment.qugame), in my quMostRecent3 leaderboard, the top 2 entries have 'vanished'. They were there yesterday. I know these players have played today, as I see their scores on other leaderboards. Any ideas how to get these back? These 2 players (me and my tester) are both TestFlight ing - not sure if that changes things.

I was wondering if there's a method on MacOS to have my application hide a hid device such as a game controller and instead have the receiving game/application see my app's virtual controller? Is this possible via DriverKit or some other form of kernel level coding? On Windows we have a tool known as HidHide that hids a game controller from all other applications. Is it possible to implement such behavior into an app or is that system level?

Hey I'm using the CIDepthBlurEffect Core Image Filter in my app. It seems to work ok but I get these errors in the console when calling the class. CoreImage Metal library does not contain function for name: sparserendering_xhlrb_scan CoreImage Metal library does not contain function for name: sparserendering_xhlrb_diffuse CoreImage Metal library does not contain function for name: sparserendering_xhlrb_copy_back CoreImage Metal library does not contain function for name: plain_or_sRGB_copy Am I missing some sort of import to gain these Metal functions? I am using my own custom shaders but I assume you'd be able to use them along side the built in ones.

I'm updating an existing distributed game to add turn-based matches. When the Matchmaker ViewController Info Button next to a game is pressed, the results vary: iOS 15.x - Button under avatar says "Accept Invite" or "View Game" (depending on if invite has already been accepted) iOS 18.x - Button always says "App Store" - I assume that means it would lead one to the App store to install the game. Both devices (iPad 15.x and iPhone 18.x) have the same version of the game installed. The results are the same when running in the simulator. When the game is released, I assume this button will work properly, no?

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.

Turn-based games: 2 players When an opponent declines a game in the Game Center MatchMaker VC, that player sees that they quit, but no message is sent to the listener about that fact. For the person who started the match, their MMVC shows it's their turn again. Why doesn't Game Center end the match?

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)

Hi, I'm trying to set the displayScale environment value for a RealityView, so it renders at 2x instead of 3x on the iPhone, but it seems to have no effect. .environment(\.displayScale, 2.0) Is this expected behavior, or a bug? The reason I want it to render at 2x and not at the default 3x is for game optimization and performance.

I do not understand how offline leaderboard submission is supposed to work in Game Kit: While the documentation briefly states that offline submission is supported, how is that even possible when you first have to fetch a leaderboard object in order to then call its submitScore function? How can I get the leaderboard object in the first place when offline? Can anyone enlighten me how this works? Or maybe point me to some relevant documentation?

After authenticating the user I'm loading my Game Center leaderboards like this: let leaderboards = try await GKLeaderboard.loadLeaderboards(IDs: [leaderboardID]) This is working fine, but there are times when this just returns an empty array. When I encounter this situation, the array remains empty for several hours when retrying, but then at some point it suddenly starts working again. Is this a known issue? Or am I hitting some kind of quota maybe (as I do it quite often while developing my game)?. Edit: My leaderboards are grouped in sets if that makes any difference here.

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)

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)

After updating iPad/iPhone devices from iOS 18 to iOS 26, PhotogrammetrySession intermittently crashes during photogrammetry processing. The same workflow was stable on iOS 18 with no code changes to the app. Environment: OS versions: Works on OS 18, crashes on OS 26 Device: iPad/iPhone (reproducible across devices) Source images: ~170-200 JPG files at 2160 x 3840 resolution Reproduction: The crash occurs consistently on the second or third sequential run of the photogrammetry session with the same image set. First run typically succeeds. Crash details: Xcode shows an uncaught exception during image processing: terminating due to uncaught exception of type std::bad_alloc: std::bad_alloc VTPixelTransferSession 420f sid 269 (2160.00 x 3840.00) [0.00 0.00 2160 3840] rowbytes( 2160, 2160 ) Color( (null), 0x0, (null), (null), ITU_R_601_4 ) => 24 sid 19 (2160.00 x 3840.00) [0.00 0.00 2160 3840] rowbytes( 6528 ) Color( 0x0, (null), (null), (null) ) This appears to be a memory allocation failure in VTPixelTransferSession during color space conversion. Has anyone else experienced similar crashes with CorePhotogrammetry on iOS 26, or found workarounds?

We are developing a hybrid iOS app where Angular content is rendered inside a WKWebView, hosted by a native Swift application. We use the GameController framework to detect whether an external Bluetooth keyboard is connected to an iPad. The following code is executed when the app enters the foreground and also when requested by the web layer: func keyboardStatusHandler(){ let isKeyboardConnected = GCKeyboard.coalesced != nil if(!isKeyboardConnected){ //sent status to Angular } else { //sent status to Angular } } Crash details We are seeing intermittent crashes on iPad with the following stack trace: Crashed: GCDeviceSession.HID 0 libobjc.A.dylib 0x7db8 objc_retain_x8 + 16 1 libsystem_blocks.dylib 0xfb8 void HelperBase<ExtendedInline>::copyCapture<(HelperBase<ExtendedInline>::BlockCaptureKind)3>(unsigned int) + 48 2 libsystem_blocks.dylib 0xbc4 HelperBase<GenericInline>::copyBlock(Block_layout*, Block_layout*) + 108 3 libsystem_blocks.dylib 0xc94 _call_copy_helpers_excp + 60 4 libsystem_blocks.dylib 0xef8 _Block_copy + 412 5 libdispatch.dylib 0x1a70 _dispatch_Block_copy + 32 6 libdispatch.dylib 0x792c dispatch_async + 56 7 libdispatch.dylib 0x792c dispatch_channel_async + 56 8 GameController 0xea6dc -[GCKeyboardInput _handleKeyboardEvent:] + 324 9 GameController 0x22508 __53-[_GCKeyboardEventHIDAdapter initWithSource:service:]_block_invoke + 376 10 GameController 0x11d30 -[_GCHIDEventSubject publishHIDEvent:] + 268 11 GameController 0xb79cc __40-[_GCHIDEventUIKitClient initWithQueue:]_block_invoke_3 + 44 12 libdispatch.dylib 0x1b584 _dispatch_client_callout + 16 13 libdispatch.dylib 0x12088 _dispatch_async_and_wait_invoke_and_complete_recurse + 272 14 libdispatch.dylib 0x8448 _dispatch_async_and_wait_f + 108 15 GameController 0xb7984 __40-[_GCHIDEventUIKitClient initWithQueue:]_block_invoke_2 + 132 16 GameController 0xb746c __48-[__GCHIDEventUIKitClient _initWithApplication:]_block_invoke + 256 17 UIKitCore 0x11fd394 __61-[UIEventFetcher _setHIDGameControllerEventObserver:onQueue:]_block_invoke_3 + 40 18 libdispatch.dylib 0x1aac _dispatch_call_block_and_release + 32 19 libdispatch.dylib 0x1b584 _dispatch_client_callout + 16 20 libdispatch.dylib 0xa2d0 _dispatch_lane_serial_drain + 740 21 libdispatch.dylib 0xadac _dispatch_lane_invoke + 388 22 libdispatch.dylib 0x151dc _dispatch_root_queue_drain_deferred_wlh + 292 23 libdispatch.dylib 0x14a60 _dispatch_workloop_worker_thread + 540 24 libsystem_pthread.dylib 0xa0c _pthread_wqthread + 292 25 libsystem_pthread.dylib 0xaac start_wqthread + 8 Observed scenarios Crash occurs when the app transitions from background to foreground Crash also occurs when the Angular layer requests keyboard status, triggering the same code path Questions Has anyone encountered crashes related to GCKeyboard.coalesced or GCKeyboardInput like this? Are there known issues with the GameController framework when querying keyboard state during app lifecycle transitions? Is there a recommended or safer way to detect external keyboard connection status on iPad (especially when using WKWebView)? Any insights, known platform issues, or suggested workarounds would be greatly appreciated. Thanks!