Hi everyone, I encountered a very strange shader bug that seems related to Metal only (not OpenGL). You can find the full description of the issue on the Babylon.js forums here: https://forum.babylonjs.com/t/strange-shader-related-issue-on-macos-with-safari-and-chrome-not-firefox/54289 (sorry, I couldn't post a clickable link here as this seems to be blocked here). I have a workaround to fix the issue (as described in the link above), but this really looks like an issue in Metal itself. Let me know if you need more details or explanations.

First I get this ar_world_tracking_provider_query_device_anchor_at_timestamp <0x302b9c0a0>: The device_anchor can only be queried when the world tracking provider is running. This seemed to all break with the auto-update to 2.0.1. Simulator runs the code fine. I seem to see an infinite stall here frameLayer.endUpdate() // Pace frames by waiting for the optimal prediction time. try await LayerRenderer.Clock().sleep(until: timing.optimalInputTime, tolerance: nil) // Start submitting the updated frame. frameLayer.startSubmission() <-

I have this game controller connected to my M1, and the Simulator won't announced it via .GCControllerDidConnect. This works fine on iOS and macOS. I have the simulator set to "Send Game Controller to Device" which the Simulator does. If I disable that, then I can control the simulator view. But once enabled, the Simulator doesn't tell the app about the controller.

We have a pixel buffer pool managed by the system(created using CVPixelBufferPoolCreate API). And each time when we need a pixel buffer, we call CVPixelBufferPoolCreatePixelBuffer to created one from the pool. Then we override all pixels of the buffer, getting IOSurface from the buffer, and then set the IOSurface as CALayer's contents property in another process to show it, everything works fine. Now we want to do some optimization by only override pixels that's changed between frames. The way we'd like to do is that after we call CVPixelBufferPoolCreatePixelBuffer to create a buffer, we get the underlying IOSurface id map it with a frame info. Next time if we get the same IOSurface id, we just compare the current frame info with the one we stored and only update the changed pixels in CVPixelBuffer. However, there is no document mentioning whether the CVPixelBuffer created using CVPixelBufferPoolCreatePixelBuffer will contain previous pixels(content before it's returned to the pool). Do we have this guarantee? If not, is there any way we can know whether the created buffer contains the previous pixels or not?

I'm trying to display a right-aligned timecode in my game. I had expected that digits would all have the same width, but this doesn't seem to be the case in SpriteKit, even though it seems to be the case in AppKit. In SpriteKit, with the default font there is a noticeable difference in width between the digit 1 and the rest (1 is thinner), so whenever displaying a number with the least significant digit 1 all preceding digits shift slightly to the right. This happens even when setting a NSAttributedString with a font that has a fixedAdvance attribute. class GameScene: SKScene { override func didMove(to view: SKView) { let label = SKLabelNode(text: "") view.scene!.addChild(label) // label.horizontalAlignmentMode = .left label.horizontalAlignmentMode = .right var i = 11 Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { _ in label.text = "\(i)" // let font = NSFont(descriptor: NSFontDescriptor(fontAttributes: [.name: "HelveticaNeue-UltraLight", .fixedAdvance: 20]), size: 30)! // let paragraphStyle = NSMutableParagraphStyle() // paragraphStyle.alignment = .right // label.attributedText = NSAttributedString(string: "\(i)", attributes: [.font: font, .foregroundColor: SKColor.labelColor, .paragraphStyle: paragraphStyle]) i += 5 } } } With AppKit, when using SpriteKit's default font HelveticaNeue-UltraLight, this issue doesn't exist, regardless whether I set the fixedAdvance font attribute. class ViewController: NSViewController { override func viewDidLoad() { super.viewDidLoad() let font = NSFont(descriptor: NSFontDescriptor(fontAttributes: [.name: "HelveticaNeue-UltraLight"]), size: 30)! // let font = NSFont(descriptor: NSFontDescriptor(fontAttributes: [.name: "HelveticaNeue-Light", .fixedAdvance: 20]), size: 30)! let paragraphStyle = NSMutableParagraphStyle() paragraphStyle.alignment = .right let textField = NSTextField(labelWithString: "") textField.font = font textField.alignment = .right // textField.alignment = .left textField.frame = CGRect(x: 100, y: 100, width: 100, height: 100) view.addSubview(textField) var i = 11 Timer.scheduledTimer(withTimeInterval: 0.5, repeats: true) { _ in textField.stringValue = "\(i)" // textField.attributedStringValue = NSAttributedString(string: "\(i)", attributes: [.font: font, .paragraphStyle: paragraphStyle]) i += 5 } } } Is there a solution to this problem? I filed FB15553700.

We've recently updated a view which displays photos via a CoreImage chain from a NSOpenGLView subclass to a NSView with a backing CAMetalLayer. Things are mostly working fine, but we occasionally hit a deadlock involving CALayer and CIMetalCommandQueue. I've made a spindump, it appears none of our code is involved in the locked threads. Despite this, I'm assuming the problem is ours 😅 I saw the mention in the CAMetalLayer documentation about releasing drawables with an @autoreleasepool in drawRect, we have done this and I can't find any places we're retaining a drawable outside drawRect. https://developer.apple.com/documentation/quartzcore/cametallayer?language=objc I am seeing this on macOS 15.0.1, M2 Max MacBookPro. We haven't seen it on macOS 14.x but it may be luck as we have not tested much on that OS. I don't know how to move forward debugging this, any help much appreciated! The two locking threads in the spindump are MainThread and CI::RenderCompletionQueue. Thread 0xb3b0f8 DispatchQueue "com.apple.main-thread"(1) … CA::Layer::commit_if_needed(CA::Transaction*, void (CA::Layer*, unsigned int, unsigned int) block_pointer) + 364 (QuartzCore + 178484) [0x1a5dba934] invocation function for block in CA::Context::commit_transaction(CA::Transaction*, double, double*) + 176 (QuartzCore + 1782676) [0x1a5f42394] -[CALayer(CALayerPrivate) _copyRenderLayer:layerFlags:commitFlags:] + 720 (QuartzCore + 179304) [0x1a5dbac68] -[NSImage(CALayerSupport) CA_copyRenderValue] + 52 (AppKit + 1517960) [0x1a0fe0988] -[NSImage CGImageForProposedRect:context:hints:] + 440 (AppKit + 1246368) [0x1a0f9e4a0] -[NSImage _usingBestRepresentationForRect:context:hints:body:] + 148 (AppKit + 1247980) [0x1a0f9eaec] __48-[NSImage CGImageForProposedRect:context:hints:]_block_invoke + 80 (AppKit + 1248792) [0x1a0f9ee18] -[NSCIImageRep CGImageForProposedRect:context:hints:] + 112 (AppKit + 6200292) [0x1a1457be4] +[CIContext contextWithOptions:] + 40 (CoreImage + 549532) [0x1a8df129c] -[CIContext initWithOptions:] + 588 (CoreImage + 65744) [0x1a8d7b0d0] +[CIContext(Internal) internalContextWithMTLDevice:options:] + 76 (CoreImage + 66568) [0x1a8d7b408] CIMetalCommandQueueCreate + 52 (CoreImage + 66692) [0x1a8d7b484] -[CaptureMTLDevice newCommandQueue] + 168 (GPUToolsCapture + 130200) [0x1029e7c98] -[CaptureMTLCommandQueue initWithBaseObject:captureDevice:] + 204 (GPUToolsCapture + 799812) [0x102a8b444] GTMTLGuestAppClientAddMTLCommandQueueInfo + 108 (GPUToolsCapture + 313572) [0x102a148e4] __ulock_wait2 + 8 (libsystem_kernel.dylib + 60540) [0x19d24bc7c] *??? (kernel.release.t6020 + 6102048) [0xfffffe0008cd5c20] (blocked by turnstile waiting for Phocus [11343] [unique pid 1001657] thread 0xb41b08 - part of a deadlock) and Thread 0xb41b08 DispatchQueue "CI::RenderCompletionQueue"(535) 1000 samples (1-1000) priority 46 (base 46) start_wqthread + 8 (libsystem_pthread.dylib + 52464) [0x1035f4cf0] _pthread_wqthread + 288 (libsystem_pthread.dylib + 20736) [0x1035ed100] _dispatch_workloop_worker_thread + 580 (libdispatch.dylib + 129956) [0x1026afba4] _dispatch_root_queue_drain_deferred_wlh + 652 (libdispatch.dylib + 133360) [0x1026b08f0] _dispatch_lane_invoke + 468 (libdispatch.dylib + 68516) [0x1026a0ba4] _dispatch_lane_serial_drain + 860 (libdispatch.dylib + 64160) [0x10269faa0] _dispatch_client_callout + 20 (libdispatch.dylib + 26788) [0x1026968a4] _dispatch_call_block_and_release + 32 (libdispatch.dylib + 19300) [0x102694b64] CI::Object::unref() const + 120 (CoreImage + 35360) [0x1a8d73a20] CI::MetalContext::~MetalContext() + 16 (CoreImage + 192260) [0x1a8d99f04] CI::MetalContext::~MetalContext() + 236 (CoreImage + 192536) [0x1a8d9a018] -[CaptureMTLCommandQueue dealloc] + 44 (GPUToolsCapture + 797916) [0x102a8acdc] GTMTLGuestAppClientRemoveMTLCommandQueueInfo + 236 (GPUToolsCapture + 314240) [0x102a14b80] GTMTLGuestAppClient_allCaptureObjectsUnsafe + 392 (GPUToolsCapture + 298776) [0x102a10f18] AllMetalLayers + 64 (GPUToolsCapture + 518224) [0x102a46850] MakeLayerInfos + 320 (GPUToolsCapture + 518608) [0x102a469d0] -[CALayer frame] + 88 (QuartzCore + 74624) [0x1a5da1380] __ulock_wait2 + 8 (libsystem_kernel.dylib + 60540) [0x19d24bc7c] *??? (kernel.release.t6020 + 6102048) [0xfffffe0008cd5c20] (blocked by turnstile waiting for Phocus [11343] [unique pid 1001657] thread 0xb3b0f8 - part of a deadlock)

This game is where you can play over 100 games and every game is very different and unique and you can save your favorite game over the 100 in store them and you can store over 100 if you like them all make your wildest dreams that you can search up as games and they could have them Youtubers, you can make good videos with this game, the Creator. :D Hope you enjoy it also I’m a kid so I don’t know how to make an update.

I want to use Swift language to write code for drawing multiple polygons. I would like to find some examples as references. Can anyone provide example code or tell me where I can see such examples? Thank you!

I've been working with ARKit and Metal on the Vision Pro, but I've encountered a slight flickering issue with the mesh rendered using Metal. The flickering tends to occur around the edges of objects or on pixels with high color contrast, and it becomes more noticeable as the distance increases. Is there any way to resolve this issue?

Hello, I am trying to obtain the RealityKit URL. Can someone share please?

Technical Issue Report for Maple Tale App - Audio Format Compatibility Dear Apple Technical Support Team, I hope this message finds you well. My name is [Your Name], and I am part of the development team behind the Maple Tale app. We have encountered an issue with audio format compatibility within our app that we believe requires your assistance. The issue pertains to the audio formats supported by our app. Currently, our app only supports WAV and OGG formats, which has led to a limitation in user experience. We are looking to expand our support to include additional formats such as MP3 and AAC, which are widely used by our user base. To provide a clear understanding of the issue, I have outlined the steps to reproduce the problem: Launch the Maple Tale app. Proceed with the game normally. Upon picking up equipment within the game, a warning box pops up indicating the audio format compatibility issue. This warning box appears due to the app's inability to process audio files in formats other than WAV and OGG. We understand that this can be a significant hindrance to the user experience, and we are eager to resolve this as quickly as possible. We have reviewed the documentation available on the official Apple Developer website but are still seeking clarification on the best practices for supporting a wider range of audio formats within our app. We would greatly appreciate any official recommendations or guidelines that could assist us in this endeavor. Additionally, we are considering updating our app to inform users about the current audio format requirements and provide guidance on how to optimize their audio files for the best performance within our app. If there are any official documents or resources that we should reference when crafting this update, please let us know. We appreciate your time and assistance in this matter and look forward to your guidance on how to best implement audio format support on the iOS platform. Thank you once again for your support. Warm regards,

Is there anywhere that the format of error/warning/other? messages that are generated by the Metal compiler are documented?

Our application uses Core Image to apply custom CIFilters to still images and video. I'm running into issues when the supplied image is large enough (>4096) that the image is automatically tiled. The simplest of these to describe is a filter that performs various mirroring effects - backwards, upside-down etc. The implementation portion of the filter provides a sampler (src) and passes this into the kernel with an roiCallback that uses the destRect, inset by -1 in both dimensions: return [mirrorsKernel applyWithExtent:[src extent] roiCallback:^CGRect(int index, CGRect destRect) { return CGRectInset(destRect, -1, -1); } arguments:@[src] ]; The kernel is very simple, sampling from the X coordinate equal to the src width - current coordinate: float4 backwards(sampler image, destination dest) { float2 dc = dest.coord(); dc.x = image.size().x - dc.x; return image.sample(image.transform(dc))); } When this runs on an image that is wider than 4096, tiling happens, with the result being that destRect is not the entire image and therefore the resulting output image is incorrect. If the ROI uses [src extent] instead of destRect, the result is correct, but this will lead to serious performance issues when src gets too large. All of this makes sense to me. What I'd like to know is if there is a way to handle this filter's requirements for sampling from the entire source while still limiting the ROI to maintain performance? I think the answer is probably no within our current structure and performance limits. But I wanted to see if there's anything we're missing. I am aware that the simple kernel above can be replaced with an affine transform, which is an option for backwards and upside-down mirroring. We have other kernels in this filter that perform mirroring of either half of the source image or one quadrant of the source image. In these cases, I suppose it might be possible (up to a point) to create a custom ROI that is only the portion of the source that is being mirrored. We have not attempted that yet. Any thoughts/input appreciated, thanks!

Even when the action is run on the main thread, the following code causes a crash on iOS, but not on macOS. The game launches with a simple yellow rectangle, and when it finishes fading out and should be removed from the overlay scene, the app crashes. The code can be pasted into the file GameController.swift of Xcode's default project for Multiplatform macOS and iOS game. import SceneKit import SpriteKit @MainActor class GameController: NSObject { let scene: SCNScene let sceneRenderer: SCNSceneRenderer init(sceneRenderer renderer: SCNSceneRenderer) { sceneRenderer = renderer scene = SCNScene(named: "Art.scnassets/ship.scn")! super.init() sceneRenderer.scene = scene renderer.overlaySKScene = SKScene(size: CGSize(width: 500, height: 500)) DispatchQueue.main.async { let node = SKShapeNode(rect: CGRect(x: 100, y: 100, width: 100, height: 100)) node.fillColor = .yellow node.run(.sequence([ .fadeOut(withDuration: 1), .removeFromParent() ])) renderer.overlaySKScene!.addChild(node) } } } The Xcode console shows this stacktrace: *** Assertion failure in -[UIApplication _performAfterCATransactionCommitsWithLegacyRunloopObserverBasedTiming:block:], UIApplication.m:3246 *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Call must be made on main thread' *** First throw call stack: ( 0 CoreFoundation 0x00000001804ae0f8 __exceptionPreprocess + 172 1 libobjc.A.dylib 0x0000000180087db4 objc_exception_throw + 56 2 Foundation 0x0000000180d17058 _userInfoForFileAndLine + 0 3 UIKitCore 0x00000001853cf678 -[UIApplication _performAfterCATransactionCommitsWithLegacyRunloopObserverBasedTiming:block:] + 376 4 UIKitCore 0x000000018553f7a0 -[_UIFocusUpdateThrottle scheduleProgrammaticFocusUpdate] + 300 5 UIKitCore 0x0000000184e2e22c -[UIFocusSystem _requestFocusUpdate:] + 548 6 UIKitCore 0x0000000184e2dfa4 -[UIFocusSystem requestFocusUpdateToEnvironment:] + 76 7 UIKitCore 0x0000000184e2e864 -[UIFocusSystem _focusEnvironmentWillDisappear:] + 408 8 SpriteKit 0x00000001a3d472f4 _ZL12_removeChildP6SKNodeS0_P7SKScene + 240 9 SpriteKit 0x00000001a3d473b0 -[SKNode removeChild:] + 80 10 SpriteKit 0x00000001a3d466b8 -[SKNode removeFromParent] + 128 11 SpriteKit 0x00000001a3d1678c -[SKRemove updateWithTarget:forTime:] + 64 12 SpriteKit 0x00000001a3d1b740 _ZN11SKCSequence27cpp_updateWithTargetForTimeEP7SKCNoded + 84 13 SpriteKit 0x00000001a3d20e3c _ZN7SKCNode6updateEdf + 156 14 SpriteKit 0x00000001a3d20f20 _ZN7SKCNode6updateEdf + 384 15 SpriteKit 0x00000001a3d26fb8 -[SKScene _update:] + 464 16 SpriteKit 0x00000001a3cf3168 -[SKSCNRenderer _update:] + 80 17 SceneKit 0x000000019c932bf0 -[SCNMTLRenderContext renderSKSceneWithRenderer:overlay:atTime:] + 60 18 SceneKit 0x000000019c9ebd98 -[SCNRenderer _drawOverlaySceneAtTime:] + 204 19 SceneKit 0x000000019cb1a1c0 _ZN3C3D11OverlayPass7executeERKNS_10RenderArgsE + 60 20 SceneKit 0x000000019c8e05ec _ZN3C3D13__renderSliceEPNS_11RenderGraphEPNS_10RenderPassERtRKNS0_9GraphNodeERPNS0_5StageENS_10RenderArgsEbRPU27objcproto16MTLCommandBuffer11objc_object + 2660 21 SceneKit 0x000000019c8e18ac _ZN3C3D11RenderGraph7executeEv + 3808 22 SceneKit 0x000000019c9ed26c -[SCNRenderer _renderSceneWithEngineContext:sceneTime:] + 756 23 SceneKit 0x000000019c9ed544 -[SCNRenderer _drawSceneWithNewRenderer:] + 208 24 SceneKit 0x000000019c9ed9fc -[SCNRenderer _drawScene:] + 40 25 SceneKit 0x000000019c9edce4 -[SCNRenderer _drawAtTime:] + 500 26 SceneKit 0x000000019ca87950 -[SCNView _drawAtTime:] + 368 27 SceneKit 0x000000019c943b74 __83-[NSObject(SCN_DisplayLinkExtensions) SCN_setupDisplayLinkWithQueue:screen:policy:]_block_invoke + 44 28 SceneKit 0x000000019ca50600 -[SCNDisplayLink _displayLinkCallbackReturningImmediately] + 132 29 libdispatch.dylib 0x000000010239173c _dispatch_client_callout + 16 30 libdispatch.dylib 0x0000000102394c14 _dispatch_continuation_pop + 756 31 libdispatch.dylib 0x00000001023aa4e0 _dispatch_source_invoke + 1736 32 libdispatch.dylib 0x00000001023997f0 _dispatch_lane_serial_drain + 340 33 libdispatch.dylib 0x000000010239a774 _dispatch_lane_invoke + 420 34 libdispatch.dylib 0x00000001023a71a8 _dispatch_root_queue_drain_deferred_wlh + 324 35 libdispatch.dylib 0x00000001023a6604 _dispatch_workloop_worker_thread + 488 36 libsystem_pthread.dylib 0x000000010242bb74 _pthread_wqthread + 284 37 libsystem_pthread.dylib 0x000000010242a934 start_wqthread + 8 ) libc++abi: terminating due to uncaught exception of type NSException Am I doing something wrong?

Hey guys, is it possible to implement mirror like reflections like in this project: https://developer.apple.com/documentation/metal/metal_sample_code_library/rendering_reflections_in_real_time_using_ray_tracing for visionOS? Or is the hardware not prepared for Metal Raytracing? Thanks in advance

Given I do not understand much at all about how to write shaders I do not understand the math associated with page-curl effects I am trying to: implement a page-curl shader for use on SwiftUI views. I've lifted a shader from HIROKI IKEUCHI that I believe they lifted from a non-metal shader resource online, and I'm trying to digest it. One thing I want to do is to paint the "underside" of the view with a given color and maintain the transparency of rounded corners when they are flipped over. So, if an underside pixel is "clear" then I want to sample the pixel at that position on the original layer instead of the "curl effect" pixel. There are two comments in the shader below where I check the alpha, and underside flags, and paint the color red as a debug test. The shader gives this result: The outside of those rounded corners is appropriately red and the white border pixels are detected as "not-clear". But the "inner" portion of the border is... mistakingly red? I don't get it. Any help would be appreciated. I feel tapped out and I don't have any IRL resources I can ask. // // PageCurl.metal // ShaderDemo3 // // Created by HIROKI IKEUCHI on 2023/10/17. // #include <metal_stdlib> #include <SwiftUI/SwiftUI_Metal.h> using namespace metal; #define pi float(3.14159265359) #define blue half4(0.0, 0.0, 1.0, 1.0) #define red half4(1.0, 0.0, 0.0, 1.0) #define radius float(0.4) // そのピクセルの色を返す [[ stitchable ]] half4 pageCurl ( float2 _position, SwiftUI::Layer layer, float4 bounds, float2 _clickedPoint, float2 _mouseCursor ) { half4 undersideColor = half4(0.5, 0.5, 1.0, 1.0); float2 originalPosition = _position; // y座標の補正 float2 position = float2(_position.x, bounds.w - _position.y); float2 clickedPoint = float2(_clickedPoint.x, bounds.w - _clickedPoint.y); float2 mouseCursor = float2(_mouseCursor.x, bounds.w - _mouseCursor.y); float aspect = bounds.z / bounds.w; float2 uv = position * float2(aspect, 1.) / bounds.zw; float2 mouse = mouseCursor.xy * float2(aspect, 1.) / bounds.zw; float2 mouseDir = normalize(abs(clickedPoint.xy) - mouseCursor.xy); float2 origin = clamp(mouse - mouseDir * mouse.x / mouseDir.x, 0., 1.); float mouseDist = clamp(length(mouse - origin) + (aspect - (abs(clickedPoint.x) / bounds.z) * aspect) / mouseDir.x, 0., aspect / mouseDir.x); if (mouseDir.x < 0.) { mouseDist = distance(mouse, origin); } float proj = dot(uv - origin, mouseDir); float dist = proj - mouseDist; float2 linePoint = uv - dist * mouseDir; half4 pixel = layer.sample(position); if (dist > radius) { pixel = half4(0.0, 0.0, 0.0, 0.0); // background behind curling layer (note: 0.0 opacity) pixel.rgb *= pow(clamp(dist - radius, 0., 1.) * 1.5, .2); } else if (dist >= 0.0) { // THIS PORTION HANDLES THE CURL SHADED PORTION OF THE RESULT // map to cylinder point float theta = asin(dist / radius); float2 p2 = linePoint + mouseDir * (pi - theta) * radius; float2 p1 = linePoint + mouseDir * theta * radius; bool underside = (p2.x <= aspect && p2.y <= 1. && p2.x > 0. && p2.y > 0.); uv = underside ? p2 : p1; uv = float2(uv.x, 1.0 - uv.y); // invert y pixel = layer.sample(uv * float2(1. / aspect, 1.) * float2(bounds[2], bounds[3])); // ME<---- if (underside && pixel.a == 0.0) { //<---- PIXEL.A IS 0.0 WHYYYYY pixel = red; } // Commented out while debugging alpha issues // if (underside && pixel.a == 0.0) { // pixel = layer.sample(originalPosition); // } else if (underside) { // pixel = undersideColor; // underside // } // Shadow the pixel being returned pixel.rgb *= pow(clamp((radius - dist) / radius, 0., 1.), .2); } else { // THIS PORTION HANDLES THE NON-CURL-SHADED PORTION OF THE SAMPLING. float2 p = linePoint + mouseDir * (abs(dist) + pi * radius); bool underside = (p.x <= aspect && p.y <= 1. && p.x > 0. && p.y > 0.); uv = underside ? p : uv; uv = float2(uv.x, 1.0 - uv.y); // invert y pixel = layer.sample(uv * float2(1. / aspect, 1.) * float2(bounds[2], bounds[3])); // ME if (underside && pixel.a == 0.0) { //<---- PIXEL.A IS 0.0 WHYYYYY pixel = red; } // Commented out while debugging alpha issues // if (underside && pixel.a == 0.0) { // // If the new underside pixel is clear, we should sample the original image's pixel. // pixel = layer.sample(originalPosition); // } else if (underside) { // pixel = undersideColor; // } } return pixel; }

Hi, I can capture a frame on the Apple TV, but when I try to profile the capture for GPU timing information, I got "Abort Trap 6" error and with following error in the report: Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Triggered by Thread: 7 Application Specific Information: abort() called Last Exception Backtrace: 0 CoreFoundation 0x18c0a99d0 __exceptionPreprocess + 160 1 libobjc.A.dylib 0x18b596d24 objc_exception_throw + 71 2 CoreFoundation 0x18bfa7308 -[__NSArrayM insertObject:atIndex:] + 1239 3 MTLReplayController 0x101f5d148 DYMTLReplayFrameProfiler_loadAnalysis + 1140 4 MTLReplayController 0x101e97f90 GTMTLReplayClient_collectGPUShaderTimelineData + 224 5 MTLReplayController 0x101e81794 __30-[GTMTLReplayService profile:]_block_invoke_4 + 288 6 Foundation 0x18eb6072c __NSOPERATION_IS_INVOKING_MAIN__ + 11 7 Foundation 0x18eb5cc1c -[NSOperation start] + 623 8 Foundation 0x18eb60edc __NSOPERATIONQUEUE_IS_STARTING_AN_OPERATION__ + 11 9 Foundation 0x18eb60bc4 __NSOQSchedule_f + 167 10 libdispatch.dylib 0x18b8d6a84 _dispatch_block_async_invoke2 + 103 11 libdispatch.dylib 0x18b8c9420 _dispatch_client_callout + 15 12 libdispatch.dylib 0x18b8cc5d0 _dispatch_continuation_pop + 531 13 libdispatch.dylib 0x18b8cbcd4 _dispatch_async_redirect_invoke + 635 14 libdispatch.dylib 0x18b8d9224 _dispatch_root_queue_drain + 335 15 libdispatch.dylib 0x18b8d9a08 _dispatch_worker_thread2 + 163 16 libsystem_pthread.dylib 0x18b6e652c _pthread_wqthread + 223 17 libsystem_pthread.dylib 0x18b6ed8d0 start_wqthread + 7 It's Xcode 16.0 + Apply TV 4K (4th Gen) tvOS 18, does anyone know what's the cause of this error and is there any solution for it? Thank you very much, Kai

Using Swift, how do I resize individual SKSpriteNodes for various iPad device sizes? Currently, I use theScene.scaleMode = .resizeFill for scaling the entire SKScene and it works as advertised. Please note that .aspectFill does not solve the challenge described below. My challenge is to resize individual SKSpriteNodes (that are components of the overall SKScene) based on size of the iOS device; for example, iPad Mini <--> iPad Pro Right now, I hard code the sizes of these Nodes. But I realize this is not the optimum approach. Again, hard coding is frowned upon. So I am looking for a more dynamic method that functions based on device size.

Hello Everyone, within the renderEncoder?.drawIndexedPrimitives(type: .line…. function, I can't render all the lines of the object. I can see approx. 80%. Do you know what could be causing this? Other game engines, like those in C++, handle this just fine. import MetalKit class Renderer: NSObject, MTKViewDelegate { var parent: ContentView var metalDevice: MTLDevice! var metalCommandQueue: MTLCommandQueue! let allocator: MTKMeshBufferAllocator let pipelineState: MTLRenderPipelineState var scene: RenderScene let mesh: ObjMesh init(_ parent: ContentView) { self.parent = parent if let metalDevice = MTLCreateSystemDefaultDevice() { self.metalDevice = metalDevice } self.metalCommandQueue = metalDevice.makeCommandQueue() self.allocator = MTKMeshBufferAllocator(device: metalDevice) mesh = ObjMesh(device: metalDevice, allocator: allocator, filename: "cube") let pipelineDescriptor = MTLRenderPipelineDescriptor() let library = metalDevice.makeDefaultLibrary() pipelineDescriptor.vertexFunction = library?.makeFunction(name: "vertexShader") pipelineDescriptor.fragmentFunction = library?.makeFunction(name: "fragmentShader") pipelineDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm pipelineDescriptor.vertexDescriptor = MTKMetalVertexDescriptorFromModelIO(mesh.metalMesh.vertexDescriptor) do { try pipelineState = metalDevice.makeRenderPipelineState(descriptor: pipelineDescriptor) } catch { fatalError() } scene = RenderScene() super.init() } func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) { } func draw(in view: MTKView) { //update scene.update() guard let drawable = view.currentDrawable else { return } let commandBuffer = metalCommandQueue.makeCommandBuffer() let renderPassDescriptor = view.currentRenderPassDescriptor renderPassDescriptor?.colorAttachments[0].clearColor = MTLClearColorMake(0, 0.5, 0.5, 1.0) renderPassDescriptor?.colorAttachments[0].loadAction = .clear renderPassDescriptor?.colorAttachments[0].storeAction = .store let renderEncoder = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPassDescriptor!) renderEncoder?.setRenderPipelineState(pipelineState) var cameraData: CameraParameters = CameraParameters() cameraData.view = Matrix44.create_lookat( eye: scene.player.position, target: scene.player.position + scene.player.forwards, up: scene.player.up ) cameraData.projection = Matrix44.create_perspective_projection( fovy: 45, aspect: 800/600, near: 0.1, far: 10 ) renderEncoder?.setVertexBytes(&cameraData, length: MemoryLayout<CameraParameters>.stride, index: 2) renderEncoder?.setVertexBuffer(mesh.metalMesh.vertexBuffers[0].buffer, offset: 0, index: 0) for cube in scene.cubes { var model: matrix_float4x4 = Matrix44.create_from_rotation(eulers: cube.eulers) model = Matrix44.create_from_translation(translation: cube.position) * model renderEncoder?.setVertexBytes(&model, length: MemoryLayout<matrix_float4x4>.stride, index: 1) for submesh in mesh.metalMesh.submeshes { renderEncoder?.drawIndexedPrimitives( type: .line, indexCount: submesh.indexCount, indexType: submesh.indexType, indexBuffer: submesh.indexBuffer.buffer, indexBufferOffset: submesh.indexBuffer.offset ) } } renderEncoder?.endEncoding() commandBuffer?.present(drawable) commandBuffer?.commit() } } ==================== import MetalKit class ObjMesh { let modelIOMesh: MDLMesh let metalMesh: MTKMesh init(device: MTLDevice, allocator: MTKMeshBufferAllocator, filename: String) { guard let meshURL = Bundle.main.url(forResource: filename, withExtension: "obj") else { fatalError() } let vertexDescriptor = MTLVertexDescriptor() var offset: Int = 0 //position vertexDescriptor.attributes[0].format = .float3 vertexDescriptor.attributes[0].offset = offset vertexDescriptor.attributes[0].bufferIndex = 0 offset += MemoryLayout<SIMD3<Float>>.stride vertexDescriptor.layouts[0].stride = offset let meshDescriptor = MTKModelIOVertexDescriptorFromMetal(vertexDescriptor) (meshDescriptor.attributes[0] as! MDLVertexAttribute).name = MDLVertexAttributePosition let asset = MDLAsset(url: meshURL, vertexDescriptor: meshDescriptor, bufferAllocator: allocator) self.modelIOMesh = asset.childObjects(of: MDLMesh.self).first as! MDLMesh do { metalMesh = try MTKMesh(mesh: self.modelIOMesh, device: device) } catch { fatalError("couldn't load mesh") } } } =============== cube.obj Blender v2.91.0 OBJ File: '' www_blender_org mtllib piece.mtl o Cube_Cube.001 v -1.000000 1.000000 -1.000000 v -1.000000 1.000000 1.000000 v 1.000000 1.000000 -1.000000 v 1.000000 1.000000 1.000000 v -1.000000 -1.000000 -1.000000 v -1.000000 -1.000000 1.000000 v 1.000000 -1.000000 -1.000000 v 1.000000 -1.000000 1.000000 vt 0.375000 0.000000 vt 0.625000 0.000000 vt 0.625000 0.250000 vt 0.375000 0.250000 vt 0.625000 0.500000 vt 0.375000 0.500000 vt 0.625000 0.750000 vt 0.375000 0.750000 vt 0.625000 1.000000 vt 0.375000 1.000000 vt 0.125000 0.500000 vt 0.125000 0.750000 vt 0.875000 0.500000 vt 0.875000 0.750000 vn 0.0000 1.0000 0.0000 vn 1.0000 0.0000 0.0000 vn 0.0000 -1.0000 0.0000 vn -1.0000 0.0000 0.0000 vn 0.0000 0.0000 -1.0000 vn 0.0000 0.0000 1.0000 usemtl None s off f 1/1/1 2/2/1 4/3/1 3/4/1 f 3/4/2 4/3/2 8/5/2 7/6/2 f 7/6/3 8/5/3 6/7/3 5/8/3 f 5/8/4 6/7/4 2/9/4 1/10/4 f 3/11/5 7/6/5 5/8/5 1/12/5 f 8/5/6 4/13/6 2/14/6 6/7/6

I'm wondering if anyone can suggest a workaround for the broken ARKit body tracking in iOS / iPadOS 18.0 and 18.1? The orientation for foot bones (and possibly other bones) is incorrect in the ARBodyAnchor returned via ARView.session.delegate update method. It works correctly in iOS / iPadOS 17.x. The same failure occurs in a SceneKit app via a ARBodyAnchor in ARSCNViewDelegate. You can easily verify the problem using Apple’s own sample app: https://developer.apple.com/documentation/arkit/arkit_in_ios/content_anchors/capturing_body_motion_in_3d Any help would be greatly appreciated.