Render advanced 3D graphics and perform data-parallel computations using graphics processors using Metal.

Posts under Metal tag

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Help Configuring Unity for Immersive VR on Vision Pro with Pinch Teleport
How do I configure a Unity project for a fully immersive VR app on Apple Vision Pro using Metal Rendering, and add a simple pinch-to-teleport-where-looking feature? I've tried the available samples and docs, but they don't cover this clearly (to me). So far, I've reviewed Unity XR docs, Apple dev guides, and tutorials, but most emphasize spatial apps. Metal examples exist but don't include teleportation. Specifically: visionOS sample "XRI_SimpleRig" – Deploys to device/simulator, but no full immersion or teleport. XRI Toolkit sample "XR Origin Hands (XR Rig)" – Pinch gestures detect, but not linked to movement. visionOS "XR Plugin" sample "Metal Sample URP" – Metal setup works, but static scene without locomotion. I'm new in Unity XR development and would appreciate a simple, standalone scene or document focused only on the essentials for "teleport to gaze on pinch" in VR mode—no extra features. I do have some experience in unreal, world toolkit, cosmo, etc from the 90's and I'm ok with code. Please include steps for: Setting up immersive VR (disabling spatial defaults if needed). Integrating pinch detection with ray-based teleport. Any config changes or basic scripts. Project Configuration: Unity Editor Version: 6000.2.5f1.2588.7373 (Revision: 6000.2/staging 43d04cd1df69) Installed Packages: Apple visionOS XR Plugin: 2.3.1 AR Foundation: 6.2.0 PolySpatial XR: 2.3.1 XR Core Utilities: 2.5.3 XR Hands: 1.6.1 XR Interaction Toolkit: 3.2.1 XR Legacy Input Helpers: 2.1.12 XR Plugin Management: 4.5.1 Imported Samples: Apple visionOS XR Plugin 2.3.1: Metal Sample - URP XR Hands 1.6.1 XR Interaction Toolkit 3.2.1: Hands Interaction Demo, Starter Assets, visionOS Build Platform Settings: Target: Apple visionOS App Mode: Metal Rendering with Compositor Services Selected Validation Profiles: visionOS Metal Documentation: Enabled Xcode Version: 26.01 visionOS SDK: 26 Mac Hardware: Apple M1 Max Target visionOS Version: 20 or 26 Test Environment: Model: Apple Vision Pro, visionOS 26.0.1 (23M341), Apple M1 Max No errors in builds so far; just missing the desired functionality. Thanks for a complete response with actionable steps.
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284
Oct ’25
Metal CIKernel instances with arbitrarily structured data arguments
Hi, In the iOS13 and macOS Catalina release notes it says: Metal CIKernel instances now support arguments with arbitrarily structured data. I've been trying to use this functionality in a CIKernel with mixed results. I'm particularly interested in passing data in the form of a dynamically sized array. It seems to work up to a certain size. Beyond the threshold excessive data is discarded and the kernel becomes unstable. I assume there is some kind of memory alignment issue going on, but I've tried various types in my array and always get a similar result. I have not found any documentation or sample code regarding this. It would be great to know how this is intended to work and what the limitations are. In the forums there are two similar unanswered questions about data arguments, so I'm sure there are a few out there with similar issues. Thanks! Michael
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597
Oct ’25
10-bit support in iPad Pro
Hi, I’m using the latest iPad Pro (13-inch) and I can see that Metal offers an rgb10a2unorm texture for rendering, but when I render a grey ramp and measure the actual luminance, I get a pattern that I would expect from an 8-bit texture (see below). Before I start ripping apart all my code, is there anything else I need to do to convince iOS to render my texture in 10-bit? I already tried setting the PixelFormat in my CMetalLayer to rgb10a2unorm, but that didn’t change anything.
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477
Sep ’25
Metal fails to create PSO on AMD based GPUs
Hello, Shaders in our application is written using HLSL and we rely on Metal Shader Converter to convert DXIL to Metal IR. We ran into an issue that causes metal pipeline state creation to fail when vertex stage-in function is used on AMD GPUs. Here's the error reported by Metal in Xcode output: Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED XPC_ERROR_CONNECTION_INTERRUPTED MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 4 try. This error suggests an unexpected interruption in the connection. Possible reasons: a crash in the compiler service, termination by the OS due to resource constraints (e.g., jetsam), a timeout in the service, or an issue with IPC. Verify system stability and check the logs for more details. Compiler failed with XPC_ERROR_CONNECTION_INVALID XPC_ERROR_CONNECTION_INVALID MTLCompiler: Compiler encountered XPC_ERROR_CONNECTION_INVALID: failed to check-in, peer may have been unloaded: mach_error=10000003 (is the OS shutting down or process jetsammed?) Compilation failed due to an interrupted connection: XPC_ERROR_CONNECTION_INTERRUPTED. This error occurred after multiple retries. which seems to indicate a internal compiler error. I have a minimal repro here: https://github.com/kcloudy0717/metal_pso_fail/tree/main, simply follow the instructions in README.
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253
Sep ’25
Xcode Cloud 26b7 Metal Compilation Failure
I've been getting intermittent failures on Xcode code compiling my app on multiple platforms because it fails to compile a metal shader. The Metal Toolchain was not installed and could not compile the Metal source files. Download the Metal Toolchain from Xcode > Settings > Components and try again. Sometimes if I re-run it, it works fine. Then I'll run it again, and it will fail. If you tell me to file a feedback, please tell me what information would be useful and actionable, because this is all I have.
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1.2k
Sep ’25
Metal Compositor Service & Persona (VisionOS)
Hello, I'm currently trying to make a collaborative app. But it just works only on Reality View, when I tried to use Compositor Layer like below, the personas disappeared. ImmersiveSpace(id: "ImmersiveSpace-Metal") { CompositorLayer(configuration: MetalLayerConfiguration()) { layerRenderer in SpatialRenderer_InitAndRun(layerRenderer) } } Is there any potential solution too see Personas in Metal view? Thanks in advance!
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777
Sep ’25
Xcode 26 Beta 3: missing Metal Toolchain
Hello community, After unable to use Metal Toolchain for Xcode Beta 1 and 2 even after following the workarounds, and using Xcode Beta 3, I am still unable to use the downloaded Metal Compiler on my device. Building any project with metal file results in warning: Could not read serialized diagnostics file: error("Failed to open diagnostics file") (in target '<target>' from project '<project>') error: error: cannot execute tool 'metal' due to missing Metal Toolchain; use: xcodebuild -downloadComponent MetalToolchain Command CompileMetalFile failed with a nonzero exit code Here is my build environment, $ xcodebuild -version Xcode 26.0 Build version 17A5276g I have also checked the downloaded metal toolchain. $ xcodebuild -downloadComponent metalToolchain -exportPath /tmp/MyMetalExport/ 2025-07-13 13:16:17.293 xcodebuild[2153:34019] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it. Beginning asset download... 2025-07-13 13:16:17.427 xcodebuild[2153:34022] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it. Downloaded asset to: /System/Library/AssetsV2/com_apple_MobileAsset_MetalToolchain/47af11e2964f385d510c6a9d1a49c8165f334a51.asset/AssetData/Restore/022-19457-052.dmg Beginning asset export... Done exporting: /tmp/MyMetalExport/MetalToolchain-17A5276g.exportedBundle Done downloading: Metal Toolchain 17A5276g. The ExportMetadata.plist has a buildUpdateVersion of 17A5276g. Any suggestions are greatly appreciated.
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Sep ’25
Xcode 26 beta 3 - Metal toolchain installed but not working
Under Xcode 26 beta 3 I'm trying to build a project which uses Metal. I've installed the Metal Toolchain 26.0 under Settings -> Components, but when I start a build it fails during the "Prepare build" step with the following error (repeated many times): stat(/var/run/com.apple.security.cryptexd/mnt/com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.Pb9SLL/Metal.xctoolchain/usr/bin/clang): No such file or directory (2) I've confirmed that there is in fact no 'clang' binary in that directory. I've tried using xcode-select to set the Xcode 26 Beta app as the active developer directory, and xcodebuild -version shows: Xcode 26.0 Build version 17A5276g Any ideas on other things to try?
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878
Sep ’25
Metal 4 & Acceleration Structures
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
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Sep ’25
JAX Metal: Random Number Generation Performance Issue on M1 Max
JAX Metal shows 55x slower random number generation compared to NVIDIA CUDA on equivalent workloads. This makes Monte Carlo simulations and scientific computing impractical on Apple Silicon. Performance Comparison NVIDIA GPU: 0.475s for 12.6M random elements M1 Max Metal: 26.3s for same workload Performance gap: 55x slower Environment Apple M1 Max, 64GB RAM, macOS Sequoia Version 15.6.1 JAX 0.4.34, jax-metal latest Backend: Metal Reproduction Code import time import jax import jax.numpy as jnp from jax import random key = random.PRNGKey(42) start_time = time.time() random_array = random.normal(key, (50000, 252)) duration = time.time() - start_time print(f"Duration: {duration:.3f}s")
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Aug ’25
[visionOS] How to render side-by-side stereo video?
I want to render a 3d/stereoscopic video in an Apple Vision Pro window using RealityKit/RealityView. The video is a left-right stereo. The straight forward approach would be to spawn a quad, and give it a custom Shader Graph material, which has a CameraIndexSwitch. The CameraIndexSwitch chooses between the right texture vs the left texture. https://i.sstatic.net/XawqjNcg.png The issue I have here is that I have to extract the video frames from my AVSampleBufferVideoRenderer. This should work ok, but not if I'm playing FairPlay content. So, my question is, how to render stereo FairPlay videos in a SwiftUI RealityView?
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818
Aug ’25
Xcode GPU capture missing initial buffer data
I'm using the WebGPU abstraction library wgpu to build an app using compute shaders that compiles to Metal (on macOS), and in certain patterns where it uses a staging buffer for initial data, the data is just total missing from the capture, breaking other workflows such as shader debugging or seeing the completed results in the final buffer. I wrote up details including a repro project and screen shots of the issue at https://github.com/gfx-rs/wgpu/issues/8111 . Seems like an Xcode bug. Any ideas? I'm happy to help investigate further if I can.
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Aug ’25
Unable to download Metal toolchain with Xcode Beta 5
I'm unable to download the Metal toolchain with Xcode. When trying to do it via the command line, I get the following: > xcodebuild -downloadComponent metalToolchain -exportPath /tmp/MyMetalExport/ Beginning asset download... 2025-08-06 19:46:19.983 xcodebuild[1395:22024] Writing error result bundle to /var/folders/48/1k1jfsxn56zcs4qr_719rc1w0000gn/T/ResultBundle_2025-06-08_19-46-0019.xcresult xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) From Console.app: DVTDownloadsFetchAssetCatalog() complete assetType (com.apple.MobileAsset.MetalToolchain), options: (MADownloadOptions allowsCellular: 0 resourceTimeout: 60 canUseCacheServer: 0 discretionary: 0 disableUI: 0 sessionId: (null) additionalServerParams:{ RequestedBuild = 17A5295f; } allowsExpensiveAccess:1 requiresPowerPluggedIn: 0 prefersInfraWiFi: 1 liveServerOnly: -1 DownloadAuthorizationHeader: not present analyticsData: not present allowDaemonConnectionRetries: 0), result: (59), catalogError: (Download failed due to not being able to find the host. (Catalog download for com.apple.MobileAsset.MetalToolchain)) Note that I am online. I've tried restarting my computer and Xcode and using a different network.
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1.5k
Aug ’25
MetalToolchain fail installation xcode 26.0 beta 5, tahoe 26.0
Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 User Info: { DVTErrorCreationDateKey = "2025-08-08 07:59:24 +0000"; } Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 Download failed due to not being able to find the host. (Catalog download for com.apple.MobileAsset.MetalToolchain) Domain: com.apple.MobileAssetError.Download Code: 59 User Info: { checkConfiguration = 1; } System Information macOS Version 26.0 (Build 25A5327h) Xcode 26.0 (24198.5) (Build 17A5295f) Timestamp: 2025-08-08T08:59:24+01:00
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Aug ’25
Can't install Metal Toolchain component
With Xcode 26.0 beta 5 (17A5295f) when I run the following command xcodebuild -downloadComponent metalToolchain I get the following error: xcodebuild[48851:12478851] Writing error result bundle to /var/folders/b_/g67r_tl557z244g20ncr_qmsd9wrz1/T/ResultBundle_2025-07-08_11-10-0012.xcresult xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) I can't install the toolchain from the Xcode GUI also. Does someone know a workaround ?
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Aug ’25
Compute kernel fails to compile when calling texture.read()
If I compile a compute kernel with a call to texture.read(), it fails with the following error: "Error Domain=AGXMetalG13X Code=3 "Encountered unlowered function call to air.get_read_sampler" UserInfo={NSLocalizedDescription=Encountered unlowered function call to air.get_read_sampler}." This error occurs on both macOS and iOS 26 Beta 5, but not when running on a simulator or in a playground. It does not occur on a macOS Sequoia VM. It occurs whether I use the old metal 3 or new metal 4 compilation method. A workaround would be to use a sampler, but according to the feature tables, all platforms support reading from textures of all formats. Below is a minimal example which produces the error: let device = MTLCreateSystemDefaultDevice()! let library = device.makeDefaultLibrary()! let computeFunction = library.makeFunction(name: "compute_test")! do { let pipeline = try device.makeComputePipelineState(function: computeFunction) debugPrint(pipeline) } catch { debugPrint("Metal 3 failed with error:\n\(error)") } #import <metal_stdlib> using namespace metal; kernel void compute_test(uint2 gid [[thread_position_in_grid]], texture2d<float, access::read> in [[texture(0)]], texture2d<float, access::write> out [[texture(1)]]) { out.write(in.read(gid), gid); } I filed feedback FB19530049.
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Aug ’25
"Metal developer tools for Windows" may sometimes freeze when running multiple instances simultaneously.
We executed the iOS package using UE5.5 on Windows. UE automatically launched the "Metal Developer Tools for Windows". I tried two versions, 5.3 and 4.4. I found that the metal.exe sometimes had no response or output was empty. The problem of no response could be alleviated by adding timeout retries, but the problem of empty output seemed to have no effect with retries. The actual command line called was: metal.exe -v --target=air64-apple-darwin18.7.0. UE relies on this output to determine the version number, and if it cannot get it, it will crash directly. During our replication test, we used a Python script to run multiple concurrent executions of the command "metal.exe -v --target=air64-apple-darwin18.7.0". On different Windows machines, it would get stuck at a certain concurrency level. Some machines even got stuck when running two tasks concurrently. We would like to ask for solutions or available versions.
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Aug ’25
RealityKit fullscreen layer
Hi! I'm currently trying to render another XR scene in front of a RealityKit one. Actually, I'm anchoring a plane to the head with a shader to display for left/right eye side-by-side images. By default, the camera has a near plane so I can directly draw at z=0. Is there a way to change the camera near plane? Or maybe there is a better solution to overlay image/texture for left/right eyes? Ideally, I would layer some kind of CompositorLayer on RealityKit, but that's sadly not possible from what I know. Thanks in advance and have a good day!
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Jul ’25
Where can I get the standalone Metal Toolchain for Xcode 26?
I'm trying to find the installer for Metal Toolchain 26. It seems to fix an issue I have but I don't want to have to install Xcode 26 just to get the toolchain installed. Is this possible?
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1
Boosts
0
Views
302
Activity
Oct ’25
Help Configuring Unity for Immersive VR on Vision Pro with Pinch Teleport
How do I configure a Unity project for a fully immersive VR app on Apple Vision Pro using Metal Rendering, and add a simple pinch-to-teleport-where-looking feature? I've tried the available samples and docs, but they don't cover this clearly (to me). So far, I've reviewed Unity XR docs, Apple dev guides, and tutorials, but most emphasize spatial apps. Metal examples exist but don't include teleportation. Specifically: visionOS sample "XRI_SimpleRig" – Deploys to device/simulator, but no full immersion or teleport. XRI Toolkit sample "XR Origin Hands (XR Rig)" – Pinch gestures detect, but not linked to movement. visionOS "XR Plugin" sample "Metal Sample URP" – Metal setup works, but static scene without locomotion. I'm new in Unity XR development and would appreciate a simple, standalone scene or document focused only on the essentials for "teleport to gaze on pinch" in VR mode—no extra features. I do have some experience in unreal, world toolkit, cosmo, etc from the 90's and I'm ok with code. Please include steps for: Setting up immersive VR (disabling spatial defaults if needed). Integrating pinch detection with ray-based teleport. Any config changes or basic scripts. Project Configuration: Unity Editor Version: 6000.2.5f1.2588.7373 (Revision: 6000.2/staging 43d04cd1df69) Installed Packages: Apple visionOS XR Plugin: 2.3.1 AR Foundation: 6.2.0 PolySpatial XR: 2.3.1 XR Core Utilities: 2.5.3 XR Hands: 1.6.1 XR Interaction Toolkit: 3.2.1 XR Legacy Input Helpers: 2.1.12 XR Plugin Management: 4.5.1 Imported Samples: Apple visionOS XR Plugin 2.3.1: Metal Sample - URP XR Hands 1.6.1 XR Interaction Toolkit 3.2.1: Hands Interaction Demo, Starter Assets, visionOS Build Platform Settings: Target: Apple visionOS App Mode: Metal Rendering with Compositor Services Selected Validation Profiles: visionOS Metal Documentation: Enabled Xcode Version: 26.01 visionOS SDK: 26 Mac Hardware: Apple M1 Max Target visionOS Version: 20 or 26 Test Environment: Model: Apple Vision Pro, visionOS 26.0.1 (23M341), Apple M1 Max No errors in builds so far; just missing the desired functionality. Thanks for a complete response with actionable steps.
Replies
0
Boosts
0
Views
284
Activity
Oct ’25
Metal CIKernel instances with arbitrarily structured data arguments
Hi, In the iOS13 and macOS Catalina release notes it says: Metal CIKernel instances now support arguments with arbitrarily structured data. I've been trying to use this functionality in a CIKernel with mixed results. I'm particularly interested in passing data in the form of a dynamically sized array. It seems to work up to a certain size. Beyond the threshold excessive data is discarded and the kernel becomes unstable. I assume there is some kind of memory alignment issue going on, but I've tried various types in my array and always get a similar result. I have not found any documentation or sample code regarding this. It would be great to know how this is intended to work and what the limitations are. In the forums there are two similar unanswered questions about data arguments, so I'm sure there are a few out there with similar issues. Thanks! Michael
Replies
5
Boosts
0
Views
597
Activity
Oct ’25
10-bit support in iPad Pro
Hi, I’m using the latest iPad Pro (13-inch) and I can see that Metal offers an rgb10a2unorm texture for rendering, but when I render a grey ramp and measure the actual luminance, I get a pattern that I would expect from an 8-bit texture (see below). Before I start ripping apart all my code, is there anything else I need to do to convince iOS to render my texture in 10-bit? I already tried setting the PixelFormat in my CMetalLayer to rgb10a2unorm, but that didn’t change anything.
Replies
1
Boosts
0
Views
477
Activity
Sep ’25
Metal fails to create PSO on AMD based GPUs
Hello, Shaders in our application is written using HLSL and we rely on Metal Shader Converter to convert DXIL to Metal IR. We ran into an issue that causes metal pipeline state creation to fail when vertex stage-in function is used on AMD GPUs. Here's the error reported by Metal in Xcode output: Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED XPC_ERROR_CONNECTION_INTERRUPTED MTLCompiler: Compilation failed with XPC_ERROR_CONNECTION_INTERRUPTED on 4 try. This error suggests an unexpected interruption in the connection. Possible reasons: a crash in the compiler service, termination by the OS due to resource constraints (e.g., jetsam), a timeout in the service, or an issue with IPC. Verify system stability and check the logs for more details. Compiler failed with XPC_ERROR_CONNECTION_INVALID XPC_ERROR_CONNECTION_INVALID MTLCompiler: Compiler encountered XPC_ERROR_CONNECTION_INVALID: failed to check-in, peer may have been unloaded: mach_error=10000003 (is the OS shutting down or process jetsammed?) Compilation failed due to an interrupted connection: XPC_ERROR_CONNECTION_INTERRUPTED. This error occurred after multiple retries. which seems to indicate a internal compiler error. I have a minimal repro here: https://github.com/kcloudy0717/metal_pso_fail/tree/main, simply follow the instructions in README.
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1
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0
Views
253
Activity
Sep ’25
Xcode Cloud 26b7 Metal Compilation Failure
I've been getting intermittent failures on Xcode code compiling my app on multiple platforms because it fails to compile a metal shader. The Metal Toolchain was not installed and could not compile the Metal source files. Download the Metal Toolchain from Xcode > Settings > Components and try again. Sometimes if I re-run it, it works fine. Then I'll run it again, and it will fail. If you tell me to file a feedback, please tell me what information would be useful and actionable, because this is all I have.
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11
Boosts
7
Views
1.2k
Activity
Sep ’25
Metal Compositor Service & Persona (VisionOS)
Hello, I'm currently trying to make a collaborative app. But it just works only on Reality View, when I tried to use Compositor Layer like below, the personas disappeared. ImmersiveSpace(id: "ImmersiveSpace-Metal") { CompositorLayer(configuration: MetalLayerConfiguration()) { layerRenderer in SpatialRenderer_InitAndRun(layerRenderer) } } Is there any potential solution too see Personas in Metal view? Thanks in advance!
Replies
2
Boosts
0
Views
777
Activity
Sep ’25
Xcode 26 Beta 3: missing Metal Toolchain
Hello community, After unable to use Metal Toolchain for Xcode Beta 1 and 2 even after following the workarounds, and using Xcode Beta 3, I am still unable to use the downloaded Metal Compiler on my device. Building any project with metal file results in warning: Could not read serialized diagnostics file: error("Failed to open diagnostics file") (in target '<target>' from project '<project>') error: error: cannot execute tool 'metal' due to missing Metal Toolchain; use: xcodebuild -downloadComponent MetalToolchain Command CompileMetalFile failed with a nonzero exit code Here is my build environment, $ xcodebuild -version Xcode 26.0 Build version 17A5276g I have also checked the downloaded metal toolchain. $ xcodebuild -downloadComponent metalToolchain -exportPath /tmp/MyMetalExport/ 2025-07-13 13:16:17.293 xcodebuild[2153:34019] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it. Beginning asset download... 2025-07-13 13:16:17.427 xcodebuild[2153:34022] IDEDownloadableMetalToolchainCoordinator: Failed to remount the Metal Toolchain: The file “com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.3KEJwX” couldn’t be opened because you don’t have permission to view it. Downloaded asset to: /System/Library/AssetsV2/com_apple_MobileAsset_MetalToolchain/47af11e2964f385d510c6a9d1a49c8165f334a51.asset/AssetData/Restore/022-19457-052.dmg Beginning asset export... Done exporting: /tmp/MyMetalExport/MetalToolchain-17A5276g.exportedBundle Done downloading: Metal Toolchain 17A5276g. The ExportMetadata.plist has a buildUpdateVersion of 17A5276g. Any suggestions are greatly appreciated.
Replies
1
Boosts
2
Views
808
Activity
Sep ’25
Xcode 26 beta 3 - Metal toolchain installed but not working
Under Xcode 26 beta 3 I'm trying to build a project which uses Metal. I've installed the Metal Toolchain 26.0 under Settings -> Components, but when I start a build it fails during the "Prepare build" step with the following error (repeated many times): stat(/var/run/com.apple.security.cryptexd/mnt/com.apple.MobileAsset.MetalToolchain-v17.1.5276.7.Pb9SLL/Metal.xctoolchain/usr/bin/clang): No such file or directory (2) I've confirmed that there is in fact no 'clang' binary in that directory. I've tried using xcode-select to set the Xcode 26 Beta app as the active developer directory, and xcodebuild -version shows: Xcode 26.0 Build version 17A5276g Any ideas on other things to try?
Replies
6
Boosts
1
Views
878
Activity
Sep ’25
Metal 4 & Acceleration Structures
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
Replies
4
Boosts
0
Views
708
Activity
Sep ’25
JAX Metal: Random Number Generation Performance Issue on M1 Max
JAX Metal shows 55x slower random number generation compared to NVIDIA CUDA on equivalent workloads. This makes Monte Carlo simulations and scientific computing impractical on Apple Silicon. Performance Comparison NVIDIA GPU: 0.475s for 12.6M random elements M1 Max Metal: 26.3s for same workload Performance gap: 55x slower Environment Apple M1 Max, 64GB RAM, macOS Sequoia Version 15.6.1 JAX 0.4.34, jax-metal latest Backend: Metal Reproduction Code import time import jax import jax.numpy as jnp from jax import random key = random.PRNGKey(42) start_time = time.time() random_array = random.normal(key, (50000, 252)) duration = time.time() - start_time print(f"Duration: {duration:.3f}s")
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0
Boosts
0
Views
551
Activity
Aug ’25
[visionOS] How to render side-by-side stereo video?
I want to render a 3d/stereoscopic video in an Apple Vision Pro window using RealityKit/RealityView. The video is a left-right stereo. The straight forward approach would be to spawn a quad, and give it a custom Shader Graph material, which has a CameraIndexSwitch. The CameraIndexSwitch chooses between the right texture vs the left texture. https://i.sstatic.net/XawqjNcg.png The issue I have here is that I have to extract the video frames from my AVSampleBufferVideoRenderer. This should work ok, but not if I'm playing FairPlay content. So, my question is, how to render stereo FairPlay videos in a SwiftUI RealityView?
Replies
1
Boosts
0
Views
818
Activity
Aug ’25
Xcode GPU capture missing initial buffer data
I'm using the WebGPU abstraction library wgpu to build an app using compute shaders that compiles to Metal (on macOS), and in certain patterns where it uses a staging buffer for initial data, the data is just total missing from the capture, breaking other workflows such as shader debugging or seeing the completed results in the final buffer. I wrote up details including a repro project and screen shots of the issue at https://github.com/gfx-rs/wgpu/issues/8111 . Seems like an Xcode bug. Any ideas? I'm happy to help investigate further if I can.
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1
Boosts
0
Views
229
Activity
Aug ’25
Unable to download Metal toolchain with Xcode Beta 5
I'm unable to download the Metal toolchain with Xcode. When trying to do it via the command line, I get the following: > xcodebuild -downloadComponent metalToolchain -exportPath /tmp/MyMetalExport/ Beginning asset download... 2025-08-06 19:46:19.983 xcodebuild[1395:22024] Writing error result bundle to /var/folders/48/1k1jfsxn56zcs4qr_719rc1w0000gn/T/ResultBundle_2025-06-08_19-46-0019.xcresult xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) From Console.app: DVTDownloadsFetchAssetCatalog() complete assetType (com.apple.MobileAsset.MetalToolchain), options: (MADownloadOptions allowsCellular: 0 resourceTimeout: 60 canUseCacheServer: 0 discretionary: 0 disableUI: 0 sessionId: (null) additionalServerParams:{ RequestedBuild = 17A5295f; } allowsExpensiveAccess:1 requiresPowerPluggedIn: 0 prefersInfraWiFi: 1 liveServerOnly: -1 DownloadAuthorizationHeader: not present analyticsData: not present allowDaemonConnectionRetries: 0), result: (59), catalogError: (Download failed due to not being able to find the host. (Catalog download for com.apple.MobileAsset.MetalToolchain)) Note that I am online. I've tried restarting my computer and Xcode and using a different network.
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20
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16
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1.5k
Activity
Aug ’25
MetalToolchain fail installation xcode 26.0 beta 5, tahoe 26.0
Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 User Info: { DVTErrorCreationDateKey = "2025-08-08 07:59:24 +0000"; } Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 Download failed due to not being able to find the host. (Catalog download for com.apple.MobileAsset.MetalToolchain) Domain: com.apple.MobileAssetError.Download Code: 59 User Info: { checkConfiguration = 1; } System Information macOS Version 26.0 (Build 25A5327h) Xcode 26.0 (24198.5) (Build 17A5295f) Timestamp: 2025-08-08T08:59:24+01:00
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6
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0
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443
Activity
Aug ’25
Can't install Metal Toolchain component
With Xcode 26.0 beta 5 (17A5295f) when I run the following command xcodebuild -downloadComponent metalToolchain I get the following error: xcodebuild[48851:12478851] Writing error result bundle to /var/folders/b_/g67r_tl557z244g20ncr_qmsd9wrz1/T/ResultBundle_2025-07-08_11-10-0012.xcresult xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) I can't install the toolchain from the Xcode GUI also. Does someone know a workaround ?
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6
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16
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671
Activity
Aug ’25
Customize the Metal Performance HUD on Apple TV
Hi there, Is it possible to customize the Metal Performance HUD on Apple TV, similar to how it can be done on iPhone & iPad? Would like to see things like Compiled Shaders for my Apps on tvOS .
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3
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0
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395
Activity
Aug ’25
Compute kernel fails to compile when calling texture.read()
If I compile a compute kernel with a call to texture.read(), it fails with the following error: "Error Domain=AGXMetalG13X Code=3 "Encountered unlowered function call to air.get_read_sampler" UserInfo={NSLocalizedDescription=Encountered unlowered function call to air.get_read_sampler}." This error occurs on both macOS and iOS 26 Beta 5, but not when running on a simulator or in a playground. It does not occur on a macOS Sequoia VM. It occurs whether I use the old metal 3 or new metal 4 compilation method. A workaround would be to use a sampler, but according to the feature tables, all platforms support reading from textures of all formats. Below is a minimal example which produces the error: let device = MTLCreateSystemDefaultDevice()! let library = device.makeDefaultLibrary()! let computeFunction = library.makeFunction(name: "compute_test")! do { let pipeline = try device.makeComputePipelineState(function: computeFunction) debugPrint(pipeline) } catch { debugPrint("Metal 3 failed with error:\n\(error)") } #import <metal_stdlib> using namespace metal; kernel void compute_test(uint2 gid [[thread_position_in_grid]], texture2d<float, access::read> in [[texture(0)]], texture2d<float, access::write> out [[texture(1)]]) { out.write(in.read(gid), gid); } I filed feedback FB19530049.
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1
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0
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248
Activity
Aug ’25
"Metal developer tools for Windows" may sometimes freeze when running multiple instances simultaneously.
We executed the iOS package using UE5.5 on Windows. UE automatically launched the "Metal Developer Tools for Windows". I tried two versions, 5.3 and 4.4. I found that the metal.exe sometimes had no response or output was empty. The problem of no response could be alleviated by adding timeout retries, but the problem of empty output seemed to have no effect with retries. The actual command line called was: metal.exe -v --target=air64-apple-darwin18.7.0. UE relies on this output to determine the version number, and if it cannot get it, it will crash directly. During our replication test, we used a Python script to run multiple concurrent executions of the command "metal.exe -v --target=air64-apple-darwin18.7.0". On different Windows machines, it would get stuck at a certain concurrency level. Some machines even got stuck when running two tasks concurrently. We would like to ask for solutions or available versions.
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1
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147
Activity
Aug ’25
RealityKit fullscreen layer
Hi! I'm currently trying to render another XR scene in front of a RealityKit one. Actually, I'm anchoring a plane to the head with a shader to display for left/right eye side-by-side images. By default, the camera has a near plane so I can directly draw at z=0. Is there a way to change the camera near plane? Or maybe there is a better solution to overlay image/texture for left/right eyes? Ideally, I would layer some kind of CompositorLayer on RealityKit, but that's sadly not possible from what I know. Thanks in advance and have a good day!
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2
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0
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339
Activity
Jul ’25