hi When analyzing our game using Instruments, I've always been confused about the two items "Drawable Present" and "Drawable Presented" in the GPU column. The timing of Drawable Present seems to be when the CPU layer calls commandbuffer:present, rather than when the actual encoding is completed on the GPU. Also, what does drawable presented specifically mean? In our case, when a CPU stall occurs, it appears that the vsync interval changes in the next frame, and a surface that has already been calculated is not displayed. Why is this happening?

Hello, I am currently working on a research project under ENINCA Consulting, focused on advanced diagnostic tools for pseudorandom number generators (structural metrics, multi-seed stability, cross-architecture reproducibility, and complementary indicators to TestU01). To validate this diagnostic framework, I prototyped a small non-linear 64-bit PRNG (not as a goal in itself, but simply as a vehicle to test the methodology). During these evaluations, I observed something interesting on Apple Silicon (Mac M1): • bit-exact reproducibility between M1 ARM CPU and M1 Metal GPU, • full BigCrush pass on both CPU and Metal backends, • excellent p-values, • stable behaviour across multiple seeds and runs. This was not the intended objective, the goal was mainly to validate the diagnostic concepts, but these results raised some questions about deterministic compute behaviour in Metal. My question: Is there any official guidance on achieving (or expecting) deterministic RNG or compute behaviour across CPU ↔ Metal GPU on Apple Silicon? More specifically: • Are deterministic compute kernels expected or guaranteed on Metal for scientific workloads? • Are there recommended patterns or best practices to ensure reproducibility across GPU generations (M1 → M2 → M3 → M4)? • Are there known Metal features that can introduce non-determinism? I am not sharing the internal recurrence (this work is proprietary), but I can discuss the high-level diagnostic observations if helpful. Thank you for any insight, very interested in how the Metal engineering team views deterministic compute patterns on Apple Silicon. Pascal ENINCA Consulting

Hi I've noticed one issue in Metal HUD, but I'm not sure if it is a bug in the Metal HUD or if there is a purpose for this behavior. Metal HUD has an option to send the data to system log in raw format where the numbers are like metal-HUD: ,,,,,..., https://developer.apple.com/documentation/xcode/monitoring-your-metal-apps-graphics-performance/ If the HUD is displayed, it works just fine, but it seems that when the HUD is hidden (with shift-F9), it still send the data to system log, but the numbers are the same all the time and are not updated while is still being updated. I would expect that it should log the data no matter if the HUD is displayed or not, this of course leads to incorrect FPS calculations Here is an example of the system log entries when the HUD is not visible:

在正常游戏中，如果非常频繁的调用assetBundle.Unload接口，会导致游戏应用画面卡死，但是游戏的背景音乐仍然正常播放。这类问题仅发生在iphone16 和iphone17的手机上，低版本的手机没有任何问题，请问该如何解决这个问题？

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?

Hi everyone, I'm new to visionOS development. I'm trying to create a physics-based scene (with gravity) where users can pick up and move objects on a workbench. I am struggling with physics interactions during the drag gesture: Kinematic Mode: If I switch to .kinematic during the drag, the object moves smoothly but clips through other objects (no collisions). Dynamic Mode: I tried keeping it .dynamic and applying linear velocity toward the hand position, but the movement feels laggy and unresponsive. Hybrid Approach: I tried switching to .kinematic during DragGesture.onChange and back to .dynamic on collision, but this causes the entity to jitter/shake violently when touching other objects. Has anyone found a clean way to drag objects while maintaining solid collisions. Thanks for your help!

I am attempting to load a jpeg image into a vImage_Buffer. I am just trying to get the data in an ARGB format. This code works fine in the Xcode 15 build , but fails with kvImageInvalidParameter error from vImageBuffer_InitWithCGImage in the Xcode 26 build. This code is written in ObjectiveC++. Here is a code fragment: int CDib_ARGB::Load(LPCSTR pFilename) { int rc = 0; if (NULL == m_pRaw_vImage_Buffer) { NSString *pNS_filename = [[NSString alloc]initWithUTF8String:pFilename]; NSImage *pNSImage = [[NSImage alloc] initWithContentsOfFile:pNS_filename]; if (nil == pNSImage) rc = -1; else { int width = pNSImage.size.width; int height = pNSImage.size.height; if (pNSImage.representations) { NSImageRep *imageRep; int jj; width = 0; height = 0; for (jj = 0; jj < pNSImage.representations.count; jj++) { imageRep = pNSImage.representations[jj]; if (imageRep.pixelsWide > width) width = imageRep.pixelsWide; if (imageRep.pixelsHigh > height) height = imageRep.pixelsHigh; } } NSSize imageSize = NSMakeSize(width, height); NSRect imageRect = NSMakeRect(0, 0, width, height); pNSImage.size = imageSize; CGImageRef cgImage = [pNSImage CGImageForProposedRect:&imageRect context:NULL hints:nil]; if (nil == cgImage) rc = -1; else { //Alloc and load vImage_Buffer. vImage_Buffer *pvImage_Buffer = new vImage_Buffer; if (NULL == pvImage_Buffer) rc = -1; else { vImage_CGImageFormat format; format.bitsPerComponent = 8; format.bitsPerPixel = 32; format.colorSpace = nil; format.bitmapInfo = kCGImageAlphaFirst | kCGBitmapByteOrderDefault;//ARGB8888 format.version = 0; format.decode = nil; format.renderingIntent = kCGRenderingIntentDefault; memset(pvImage_Buffer, 0, sizeof(vImage_Buffer)); long status = vImageBuffer_InitWithCGImage(pvImage_Buffer, &format, nil, cgImage, kvImagePrintDiagnosticsToConsole); if (kvImageNoError != status) { //This is where Xcode 26 sends me. delete pvImage_Buffer; rc = -1; } =========================

I've been using Metal compute shaders for lattice quantum chromodynamics simulations and wanted to share the experience in case others are doing scientific computing on Metal. The workload involves SU(2) matrix operations on 4D lattice grids — lots of 2x2 and 3x3 complex matrix multiplies, reductions over lattice sites, and nearest-neighbor stencil operations. The implementation bridges a C++ scientific framework (Grid) to Metal via Objective-C++ .mm files, with MSL kernels compiled into .metallib archives during the build. Things that work well: Shared memory on M-series eliminates the CPU↔GPU copy overhead that dominates in CUDA workflows The .metallib compilation integrates cleanly with autotools builds using xcrun Float4 packing for SU(2) matrices maps naturally to MSL vector types Things I'm still figuring out: Optimal threadgroup sizes for stencil operations on 4D grids Whether to use MTLHeap for gauge field storage or stick with individual buffers Best practices for double precision — some measurements need float64 but Metal's double support varies by hardware The application is measuring chromofield flux distributions between static quarks, ultimately targeting multi-quark systems. Production runs are on MacBook Pro M-series and Mac Studio. Code: https://github.com/ThinkOffApp/multiquark-lattice-qcd

We have a macOS app (not yet released, but in use by ourselves), that provides scoreboards for streaming sport events. Today it is expected, that there are nice animations for goals, etc. We are streaming using NDI, which requires a CVPixelBuffer for each frame. We currently create these animations using CABasicAnimation, CAAnimation and CAKeyframeAnimation. In addition we use ScreenCaptureKit to generate the frames. This works fine with 25/30 fps, as long as the window where our animations are performed in is visible. But this is not what it should be. We have a smaller window as main app window and control display performing the animations in reduced size, while the streaming animations need to be in HD format and later maybe in 4K. When using an offscreen window, the animations are not calculated. We get 1 frame per second or so. So we actually have to connect an external display to the MacBook and open the large windows there. Ugly solution. Do we use a completely wrong approach? Or is there a way to tell the macOS to perform the animations although it is an offscreen window? If it cannot work that way, what is an alternative?

I asked AI to build a realistic ocean shader for a VisionOS project using RealityKit. It gave a bunch instructions and asked me to connect large amount of nodes for the ShaderGraph in the Reality Composer Pro. I am just wondering if AI can help to generate the Metal shader code directly, or build the ShaderGraph nodes for me automatically.

Hello, I'm working on a game that features online multiplayer. The game is developed using Unity and Apple Unity plugins. The "isUnderAge" property restricts the online multiplayer feature. Everything works as expected on all platforms (Mac, iPhone, iPad, AppleTV, and visionPro) except on Macs equipped with an Intel chip. Using the same iCloud and GameCenter, with no restrictions enabled, "isUnderAge" returns false, as expected, but on Mac equipped with an Intel chip, it returns true. Is there any restriction or compatibility issue with those chips? Is there a workaround? Thanks

I've coded a text-adventure game in SwiftUI. (My game has no graphics or sound effects.) My app already supports keyboard navigation; I would like to add support for game controllers on iPhone. I can't figure out how to do it. I especially can't see any way to allow controller users to enter text in a TextField. I've read https://developer.apple.com/documentation/gamecontroller/supporting-game-controllers and it's all about button events. There's no reference to SwiftUI at all in that documentation, or any input-method editing at all. The only mention of "keyboard" is about treating the keyboard itself as if it were a game controller providing button events. How do I implement this?

Unable to find intelgpu_kbl_gt2r0 slice or a compatible one in binary archive 'file:///System/Library/PrivateFrameworks/IconRendering.framework/Resources/binary.metallib' available slices: applegpu_g13g, applegpu_g13s, applegpu_g13d, applegpu_g14g, applegpu_g14s, applegpu_g14d, applegpu_g15g, applegpu_g15s, applegpu_g15d, applegpu_g16g, applegpu_g16s, applegpu_g17g, applegpu_g15g, applegpu_g15s, applegpu_g15d, applegpu_g16s Is it related to performance of applications in macOS 26.2 on Intel Macs?

My procedural animation using IKRig occasionally jitters and throws this warning. It completely breaks immersion. getMoCapTask: Rig must be of type kCoreIKSolverTypePoseRetarget Any idea where to start looking or what could be causing this?

App Storeにある『浮遊時計 Premium』は1Hzごとか10Hzごと、または3段階以上のリフレッシュレート計測はできますか？

I am currently using RealityKit (perspective camera) to render a character in my swiftUI app. The character has customization such as clothing items and hair and all objects are properly weighted to the rig. The way the model is setup in Blender is like so: Groups of objects that will be swapped (ex: Shoes -> Shoes objects) and an armature. I then export it to usdc with all objects active. This is the resulting entity hierarchy, viewed in Reality Composer Pro: My problem is that when I export with the Armature Modifier applied to the objects, so that animations get exported, the ModelComponent gets flattened to the armature and swapping entities is no longer as simple as removing the entity with the corresponding name. What's the best practice here? Should animation be exported separately and then applied to the skeleton? If so, how is that achieved? I'm not really sure how to proceed here.

How can one match the walls and floor of a given CapturedRoom ? The transform.eulerAngles of a floor z & y are always 0 ! And the polygons seems to have a different orientation than the walls. So how to figure out the rotation and match the one from the walls ?

Hello I would like to know how to combine 2 animations with RealityKit (one animation for the arms and one for the legs for example) I saw this apple demo that seems to explain it but I don't understand at all how to do it... Thanks

I am using the latest version of the Game Center plugin for Unity and have noticed that my game will crash on launch when trying to authenticate. I've tried this in an empty project with just the plugin and it still crashes with this exception. GfxDevice: creating device client; threaded=1; jobified=0 Initializing Metal device caps: Apple A14 GPU Initialize engine version: 2022.3.62f2 (7670c08855a9) GameKitException: Code=-7 Domain=GKErrorDomain Description=The operation couldn’t be completed. (GKErrorDomain error -7.) (UnsupportedOperationForOSVersion) at Apple.GameKit.DefaultNSErrorHandler.ThrowNSError (System.IntPtr nsErrorPtr) [0x00000] in <00000000000000000000000000000000>:0 Rethrow as TypeInitializationException: The type initializer for 'Apple.GameKit.GKGameActivity' threw an exception. And the area in the native code that is triggering the crash is this inside the GKLocalPlayer_SetAuthenticateHandler function `_onAuthenticate!(tid, _mostRecentAuthenticatePlayer!.passRetainedUnsafeMutablePointer()); I am using Unity 2022.3.62f2 and MacOS 15.6 with iOS 18.6.2 which based on the min specs for the plugin we should be within spec. I have also included this message because I thought it might help too `terminating due to uncaught exception of type Il2CppExceptionWrapper Could not import Swift modules for translation unit: failed to get module "GameKitWrapper" from AST context: error: 'GKErrorCodeExtension.h' file not found in file included from :1: error: could not build Objective-C module 'GameKitWrapper' warning: Ignoring missing VFS file: /Users/james/Library/Developer/Xcode/DerivedData/GameKitWrapper-dzawbtxqdxdviiakfxmfunexppqv/Build/Intermediates.noindex/GameKitWrapper.build/Release-iphoneos/GameKitWrapper-bc72bd3638f4d2956cac9b00e84c1a7d-VFS-iphoneos/all-product-headers.yaml This is the likely root cause for any subsequent compiler errors.warning: Ignoring missing VFS file: /Users/bill/Library/Developer/Xcode/DerivedData/GameKitWrapper-dzawbtxqdxdviiakfxmfunexppqv/Build/Intermediates.noindex/GameKitWrapper.build/Release-iphoneos/GameKitWrapper iOS.build/unextended-module-overlay.yaml This is the likely root cause for any subsequent compiler errors.warning: TypeSystemSwiftTypeRef::GetNumChildren: had to engage SwiftASTContext fallback for type $syyXCD I've also attached the script that I am using for authentication, this script runs on the first scene. GameCenterManager.cs

I have really enjoyed looking through the code and videos related to Metal 4. Currently, my interest is to update a ReSTIR Project and take advantage of more robust ways to refit acceleration Structures and more powerful ways to access resources. I am working in Swift and have encountered a couple of puzzles: What is the 'accepted' way to create a MTL4BufferRange to store indices and vertices? How do I properly rewrite Swift code to build and compact an Acceleration Structure? I do realize that this is all in Beta and will happily look through Code Samples this Fall. If other guidance is available earlier, that would be fabulous! Thank you