The following minimal snippet SEGFAULTS with SDK 26.0 and 26.1. Won't crash if I remove async from the enclosing function signature - but it's impractical in a real project. import Metal import MetalPerformanceShaders let SEED = UInt64(0x0) typealias T = Float16 /* Why ran in async context? Because global GPU object, and async makeMTLFunction, and async makeMTLComputePipelineState. Nevertheless, can trigger the bug without using global @MainActor let myGPU = MyGPU() */ @main struct CMDLine { static func main() async { let ptr = UnsafeMutablePointer<T>.allocate(capacity: 0) async let future: Void = randomFillOnGPU(ptr, count: 0) print("Main thread is playing around") await future print("Successfully reached the end.") } static func randomFillOnGPU(_ buf: UnsafeMutablePointer<T>, count destbufcount: Int) async { // let (device, queue) = await (myGPU.device, myGPU.commandqueue) let myGPU = MyGPU() let (device, queue) = (myGPU.device, myGPU.commandqueue) // Init MTLBuffer, async let makeFunction, makeComputePipelineState, etc. let tempDataType = MPSDataType.uInt32 let randfiller = MPSMatrixRandomMTGP32(device: device, destinationDataType: tempDataType, seed: Int(bitPattern:UInt(SEED))) print("randomFillOnGPU: successfully created MPSMatrixRandom.") // try await computePipelineState // ^ Crashes before this could return // Or in this minimal case, after randomFillOnGPU() returns // make encoder, set pso, dispatch, commit... } } actor MyGPU { let device : MTLDevice let commandqueue : MTLCommandQueue init() { guard let dev: MTLDevice = MPSGetPreferredDevice(.skipRemovable), let cq = dev.makeCommandQueue(), dev.supportsFamily(.apple6) || dev.supportsFamily(.mac2) else { print("Unable to get Metal Device! Exiting"); exit(EX_UNAVAILABLE) } print("Selected device: \(String(format: "%llX", dev.registryID))") self.device = dev self.commandqueue = cq print("myGPU: initialization complete.") } } See FB20916929. Apparently objc autorelease pool is releasing the wrong address during context switch (across suspension points). I wonder why such obvious case has not been caught before.

I recently needed to develop an application to obtain the window list, which requires Screen Recording permissions. Apple's official documentation mentions using the two functions CGPreflightScreenCaptureAccess and CGRequestScreenCaptureAccess to request permissions. These functions are stated to be available since version 10.15. However, when I used these two functions on a device running macOS 10.15.7, I encountered the errors shown in the attached screenshot. I used the nm tool to inspect the symbols in the CoreGraphics.framework and found that these two functions were not present. Could you help me understand why this is happening?

I am puzzled by the setAddress(_:attributeStride:index:) of MTL4ArgumentTable. Can anyone please explain what the attributeStride parameter is for? The doc says that it is "The stride between attributes in the buffer." but why? Who uses this for what? On the C++ side in the shaders the stride is determined by the C++ type, as far as I know. What am I missing here? Thanks!

I am trying to implement a ChacterControllerComponent using the following URL. https://developer.apple.com/documentation/realitykit/charactercontrollercomponent I have written sample code, but PhysicsSimulationEvents.WillSimulate is not executed and nothing happens. import SwiftUI import RealityKit import RealityKitContent struct ImmersiveView: View { let gravity: SIMD3<Float> = [0, -50, 0] let jumpSpeed: Float = 10 enum PlayerInput { case none, jump } @State private var testCharacter: Entity = Entity() @State private var myPlayerInput = PlayerInput.none var body: some View { RealityView { content in // Add the initial RealityKit content if let immersiveContentEntity = try? await Entity(named: "Immersive", in: realityKitContentBundle) { content.add(immersiveContentEntity) testCharacter = immersiveContentEntity.findEntity(named: "Capsule")! testCharacter.components.set(CharacterControllerComponent()) let _ = content.subscribe(to: PhysicsSimulationEvents.WillSimulate.self, on: testCharacter) { event in print("subscribe run") let deltaTime: Float = Float(event.deltaTime) var velocity: SIMD3<Float> = .zero var isOnGround: Bool = false // RealityKit automatically adds `CharacterControllerStateComponent` after moving the character for the first time. if let ccState = testCharacter.components[CharacterControllerStateComponent.self] { velocity = ccState.velocity isOnGround = ccState.isOnGround } if !isOnGround { // Gravity is a force, so you need to accumulate it for each frame. velocity += gravity * deltaTime } else if myPlayerInput == .jump { // Set the character's velocity directly to launch it in the air when the player jumps. velocity.y = jumpSpeed } testCharacter.moveCharacter(by: velocity * deltaTime, deltaTime: deltaTime, relativeTo: nil) { event in print("playerEntity collided with \(event.hitEntity.name)") } } } } } } The scene is loaded from RCP. It is simple, just a capsule on a pedestal. Do I need a separate code to run testCharacter from this state?

Hi! Using ARView in UIKit or through a UIViewRepresentable in SwiftUI, we can do: arView.debugOptions = [.showPhysics, .showStatistics] What is the equivalent in RealityView?

Problem Description I'm encountering an issue with SCNTechnique where the clearColor setting is being ignored when multiple passes share the same depth buffer. The clear color always appears as the scene background, regardless of what value I set. The minimal project for reproducing the issue: https://www.dropbox.com/scl/fi/30mx06xunh75wgl3t4sbd/SCNTechniqueCustomSymbols.zip?rlkey=yuehjtk7xh2pmdbetv2r8t2lx&st=b9uobpkp&dl=0 Problem Details In my SCNTechnique configuration, I have two passes that need to share the same depth buffer for proper occlusion handling: "passes": [ "box1_pass": [ "draw": "DRAW_SCENE", "includeCategoryMask": 1, "colorStates": [ "clear": true, "clearColor": "0 0 0 0" // Expecting transparent black ], "depthStates": [ "clear": true, "enableWrite": true ], "outputs": [ "depth": "box1_depth", "color": "box1_color" ], ], "box2_pass": [ "draw": "DRAW_SCENE", "includeCategoryMask": 2, "colorStates": [ "clear": true, "clearColor": "0 0 0 0" // Also expecting transparent black ], "depthStates": [ "clear": false, "enableWrite": false ], "outputs": [ "depth": "box1_depth", // Sharing the same depth buffer "color": "box2_color", ], ], "final_quad": [ "draw": "DRAW_QUAD", "metalVertexShader": "myVertexShader", "metalFragmentShader": "myFragmentShader", "inputs": [ "box1_color": "box1_color", "box2_color": "box2_color", ], "outputs": [ "color": "COLOR" ] ] ] And the metal shader used to display box1_color and box2_color with splitting: fragment half4 myFragmentShader(VertexOut in [[stage_in]], texture2d<half, access::sample> box1_color [[texture(0)]], texture2d<half, access::sample> box2_color [[texture(1)]]) { half4 color1 = box1_color.sample(s, in.texcoord); half4 color2 = box2_color.sample(s, in.texcoord); if (in.texcoord.x < 0.5) { return color1; } return color2; }; Expected Behavior Both passes should clear their color targets to transparent black (0, 0, 0, 0) The depth buffer should be shared between passes for proper occlusion Actual Behavior Both box1_color and box2_color targets contain the scene background instead of being cleared to transparent (see attached image) This happens even when I explicitly set clearColor: "0 0 0 0" for both passes Setting scene.background.contents = UIColor.clear makes the clearColor work as expected, but I need to keep the scene background for other purposes What I've Tried Setting different clearColor values - all are ignored when sharing depth buffer Using DRAW_NODE instead of DRAW_SCENE - didn't solve the issue Creating a separate pass to capture the background - the background still appears in the other passes Various combinations of clear flags and render orders Environment iOS/macOS, running with "My Mac (Designed for iPad)" Xcode 16.2 Question Is this a known limitation of SceneKit when passes share a depth buffer? Is there a workaround to achieve truly transparent clear colors while maintaining a shared depth buffer for occlusion testing? The core issue seems to be that SceneKit automatically renders the scene background in every DRAW_SCENE pass when a shared depth buffer is detected, overriding any clearColor settings. Any insights or workarounds would be greatly appreciated. Thank you!

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?

Hi, wanted to test if possible to use Mesa3D OGLon12+D3DMetal 2b3 to get GL>4.1 support on windows apps via D3D12Metal.. using simple wglgears.c app (similar glxgears) and running like: GALLIUM_DRIVER=d3d12 wine64 wglgears64 -info with overridden opengl32.dll using contents from: https://github.com/pal1000/mesa-dist-win/releases/download/24.3.0-rc1/mesa3d-24.3.0-rc1-release-msvc.7z I get: [D3DMetal:LOG:5E53] Unsupported API: CreateCommandQueue1 caused by: https://gitlab.freedesktop.org/mesa/mesa/-/commit/c022c9603d500b59ff5e6f93c8a214d1785ab20a API: https://learn.microsoft.com/en-us/windows/win32/api/d3d12/nf-d3d12-id3d12device9-createcommandqueue1 note setup is correct as using: GALLIUM_DRIVER=llvmpipe wine64 wglgears64 -info I get: GL_RENDERER = llvmpipe (LLVM 19.1.3, 128 bits) GL_VERSION = 4.5 (Compatibility Profile) Mesa 24.3.0-rc1 (git-85ba713d76) GL_VENDOR = Mesa GL_EXTENSIONS = GL_ARB_multisample GL_EXT_abgr GL_EXT_bgra GL_EXT_blend_color GL_EXT_blend_minmax GL_EXT_blend_subtract r GL_EXT_texture.. etc..

Hello! I'm a developer working on a plugin for the Elgato Stream Deck, called GPU Metrics. The plugin currently only works on Windows but I'd like to bring it to macOS. However, based on forum posts I've read (and StackOverflow) there isn't a very clear path to query GPU metrics like usage, temperature, used GPU memory, and power consumption. There are some tools out there that do similar things, but I wanted to see what would be the recommendation from Apple's engineering team to get this data via a public API. Requirements: Access GPU utilization, temperature, memory usage, power usage C/C++ based API for querying the metrics so I can expose the data to JavaScript via Node Addon No need to compatibile with Intel-based Macs, as Apple silicon will be fine for now Plugin GitHub Thank you! Noah

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

Hello, when I'm looking to customize the icons of my phone, the applications that are in the grouping genres without replacing with all-black images, I don't know what happens by changing the color of the applications in group of change no color throws just listen not the black stuff

Hi everyone, We’re currently porting a high-fidelity AA+ PC title built on Unreal Engine 5.7 to macOS (Apple Silicon), and we’re looking for guidance from anyone with experience in this area. At the moment, the game is already runnable on Mac, but not yet at a playable level — we’re seeing performance around 10–15 FPS on an M4 device. We’re actively analyzing and defining the work needed to reach production-quality performance on macOS. One of the key areas we’re exploring is leveraging MetalFX to improve frame rate. However, it seems there’s no official MetalFX plugin or direct integration available for Unreal Engine. Has anyone here successfully integrated MetalFX into a UE5 rendering pipeline, or found a recommended approach to do so? Any insights on best practices, workflows, or references (docs, samples, etc.) would be greatly appreciated. Thanks in advance!

Hey everyone, I am currently developing an app in visionOS and using RealityComposerPro create scenes in put in my app. I have a humanoid model with hair strands, and each strand of hair has an opacity map. However, some reflections are still visible even though the opacity is zero. There are also some weird culling among hair strands (in the left circle) and weird reflections in hair cards (in the right circle). Here's my settings for the materials. Since all the hair strands are interconnected with each other, it is hard to decide the drawing order in Xcode, so I am wondering if there's an easier way to handle transparency objects. Please let me know if you know anything helpful, much appreciated!

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; } =========================

The sample code just draw a triangle and sample texture. both sample code can draw a correct triangle and sample texture as expected. there are no error message from terminal. Sample code using constexpr Sampler can capture and replay well. Sample code using a argumentTable to bind a MTLSamplerState was crashed when using Metal capture and replay on Xcode. Here are sample codes. Sample Code Test Environment: M1 Pro MacOS 26.3 (25D125) Xcode Version 26.2 (17C52) Feedback ID: FB22031701

Looks like is something to do with the code and that is why my images are distorted. please help me get to the right person to help me get this issue resolved

When building a Unity iOS game, the app name displays incorrectly as "BigBall" on the iPhone home screen, despite setting the project name and bundle identifier to "Big Ball" in Unity and Apple Developer account. The correct name, "Big Ball," appears in TestFlight. I tried solutions from ChatGPT and DeepSeek, but none were satisfactory. Please help me.

I implemented an EntityAction to change the baseColor tint - and had it working on VisionOS 2.x. import RealityKit import UIKit typealias Float4 = SIMD4<Float> extension UIColor { var float4: Float4 { if cgColor.numberOfComponents == 4, let c = cgColor.components { Float4(Float(c[0]), Float(c[1]), Float(c[2]), Float(c[3])) } else { Float4() } } } struct ColourAction: EntityAction { // MARK: - PUBLIC PROPERTIES let startColour: Float4 let targetColour: Float4 // MARK: - PUBLIC COMPUTED PROPERTIES var animatedValueType: (any AnimatableData.Type)? { Float4.self } // MARK: - INITIATION init(startColour: UIColor, targetColour: UIColor) { self.startColour = startColour.float4 self.targetColour = targetColour.float4 } // MARK: - PUBLIC STATIC FUNCTIONS @MainActor static func registerEntityAction() { ColourAction.subscribe(to: .updated) { event in guard let animationState = event.animationState else { return } let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime)) animationState.storeAnimatedValue(interpolatedColour) } } } extension Entity { // MARK: - PUBLIC FUNCTIONS func changeColourTo(_ targetColour: UIColor, duration: Double) { guard let modelComponent = components[ModelComponent.self], let material = modelComponent.materials.first as? PhysicallyBasedMaterial else { return } let colourAction = ColourAction(startColour: material.baseColor.tint, targetColour: targetColour) if let colourAnimation = try? AnimationResource.makeActionAnimation(for: colourAction, duration: duration, bindTarget: .material(0).baseColorTint) { playAnimation(colourAnimation) } } } This doesn't work in VisionOS 26. My current fix is to directly set the material base colour - but this feels like the wrong approach: @MainActor static func registerEntityAction() { ColourAction.subscribe(to: .updated) { event in guard let animationState = event.animationState, let entity = event.targetEntity, let modelComponent = entity.components[ModelComponent.self], var material = modelComponent.materials.first as? PhysicallyBasedMaterial else { return } let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime)) material.baseColor.tint = UIColor(interpolatedColour) entity.components[ModelComponent.self]?.materials[0] = material animationState.storeAnimatedValue(interpolatedColour) } } So before I raise this as a bug, was I doing anything wrong in the former version and got lucky? Is there a better approach?

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