Hi, I wanted to do something quite simple: Put a box on a wall or on the floor. My box: let myBox = ModelEntity( mesh: .generateBox(size: SIMD3<Float>(0.1, 0.1, 0.01)), materials: [SimpleMaterial(color: .systemRed, isMetallic: false)], collisionShape: .generateBox(size: SIMD3<Float>(0.1, 0.1, 0.01)), mass: 0.0) For that I used Plane Detection to identify the walls and floor in the room. Then with SpatialTapGesture I was able to retrieve the position where the user is looking and tap. let position = value.convert(value.location3D, from: .local, to: .scene) And then positioned my box myBox.setPosition(position, relativeTo: nil) When I then tested it I realized that the box was not parallel to the wall but had a slightly inclined angle. I also realized if I tried to put my box on the wall to my left the box was placed perpendicular to this wall and not placed on it. After various searches and several attempts I ended up playing with transform.matrix to identify if the plane is wall or a floor, if it was in front of me or on the side and set up a rotation on the box to "place" it on the wall or a floor. let surfaceTransform = surface.transform.matrix let surfaceNormal = normalize(surfaceTransform.columns.2.xyz) let baseRotation = simd_quatf(angle: .pi, axis: SIMD3<Float>(0, 1, 0)) var finalRotation: simd_quatf if acos(abs(dot(surfaceNormal, SIMD3<Float>(0, 1, 0)))) < 0.3 { logger.info("Surface: ceiling/floor") finalRotation = simd_quatf(angle: surfaceNormal.y > 0 ? 0 : .pi, axis: SIMD3<Float>(1, 0, 0)) } else if abs(surfaceNormal.x) > abs(surfaceNormal.z) { logger.info("Surface: left/right") finalRotation = simd_quatf(angle: surfaceNormal.x > 0 ? .pi/2 : -.pi/2, axis: SIMD3<Float>(0, 1, 0)) } else { logger.info("Surface: front/back") finalRotation = baseRotation } Playing with matrices is not really my thing so I don't know if I'm doing it right. Could you tell me if my tests for the orientation of the walls are correct? During my tests I don't always correctly identify whether the wall is in front or on the side. Is this generally the right way to do it? Is there an easier way to do this? Regards Tof

Like many folks here, I've recently attempted to build Apple's Game Porting Toolkit on my machine and ran into compiler errors, but instead of going the usual route of downloading the prebuilt package (kindly provided by GCenX), I decided to see if I could force it to build (since it was obviously buildable at some point). Down below is the list of things I had to do to make it work. Disclaimer: There are several dirty hacks I had to attempt to force the system to do what I needed. Use at your own risk. Don't forget to run all brew commands from a Rosetta prompt: arch -x86_64 zsh Install openssl This one is easy. Just run brew tap rbenv/tap brew install rbenv/tap/openssl@1.1 Install Command Line Tools 15.1 This specific version is required since newer versions come with the linker that is not compatible with the custom compiler (game-porting-toolkit-compiler) that GPTK is using. However, by default 15.1 tools won't install on Sequoia since the installer complains that macOS version is too new. Obviously, Apple has their reasons to not allow this, but all we need is a compiler which should be mostly indifferent to the OS version. To trick the installer, we need to change OS requirement of the installer package. You can do it in four easy steps: Copy Command Line Tools.pkg from the mounted Command_Line_Tools_for_Xcode_15.1.dmg to some other directory. Expand the installer package: pkgutil --expand "Command Line Tools.pkg" CLT You might be prompted to install Command Line Tools when you call pkgutil, just install any version. Go to the newly created CLT folder and edit the Distribution file (it may appear as executable but it's just an xml). You would want to change allowed-os-versions to something greater than 15. Removing this section altogether might also work. When done, re-wrap the package: pkgutil --flatten CLT "Command Line Tools 2.pkg" Congratulations, now you should be able to install 15.1 tools on your OS! If you had to install newer Command Line Tools for pkgutil, delete them before installing 15.1: sudo rm -rf /Library/Developer/CommandLineTools Next step is to make Homebrew accept the outdated 15.1 tools, as by default it'll complain that they're outdated or corrupted. To shut it up, open /usr/local/Homebrew/Library/Homebrew/extend/os/Mac/diagnostic.rb and remove references to check_if_supported_sdk_available from a couple of fatal build check collections. Note - by default, Homebrew will auto-update on any invocation, which will overwrite any changes you've made to its internals. To disable this behavior, before running any brew commands in the terminal, run export HOMEBREW_NO_AUTO_UPDATE=1 After these manipulations, Homebrew might still complain about outdated Command Line Tools, but it won't be a fatal error anymore. Finally, we need to downgrade MinGW to 11.0.1, since the latest version spits out compiler errors when compiling Wine. Unfortunately, Homebrew does a bad job tracking versions of MinGW, so there is no automatic way to do it. Instead, you have to manually download and install old MinGW 11.0.1 formula from the Homebrew git repository. I used the commit from Sep 16, 2023: https://github.com/Homebrew/homebrew-core/blob/b95f4f9491394af667943bd92b081046ba3406f2/Formula/m/mingw-w64.rb Download the file above, save it in your current working directory, and then run brew install ./mingw-w64.rb If you had a newer version of MinGW already installed from the previous build attempts, you can unlink it before installing the one above: brew unlink mingw-w64 With Command Line Tools 15.1 and MinGW 11.0.1 you should now be able to build GPTK without errors: brew -v install apple/apple/game-porting-toolkit In the end, steps above worked for me, although more things could break in the future. I'm leaving the instructions here just to show that it's still possible to build GPTK manually instead of relying on third parties, but with all the hoops I had to jump through I can't really recommend it.

Hi, I'm working with a very simple app that tries to read a coordinates card and past the data into diferent fields. The card's layout is COLUMNS from 1-10, ROWs from A-J and a two digit number for each cell. In my app, I have field for each of those cells (A1, A2...). I want that OCR to read that card and paste the info but I just cant. I have two problems. The camera won't close. It remains open until I press the button SAVE (this is not good because a user could take 3, 4, 5... pictures of the same card with, maybe, different results, and then? Which is the good one?). Then, after I press save, I can see the OCR kinda works ( the console prints all the date read) but the info is not pasted at all. Any idea? I know is hard to know what's wrong but I've tried chatgpt and all it does... just doesn't work This is the code from the scanview import SwiftUI import Vision import VisionKit struct ScanCardView: UIViewControllerRepresentable { @Binding var scannedCoordinates: [String: String] var useLettersForColumns: Bool var numberOfColumns: Int var numberOfRows: Int @Environment(.presentationMode) var presentationMode func makeUIViewController(context: Context) -&gt; VNDocumentCameraViewController { let scannerVC = VNDocumentCameraViewController() scannerVC.delegate = context.coordinator return scannerVC } func updateUIViewController(_ uiViewController: VNDocumentCameraViewController, context: Context) {} func makeCoordinator() -&gt; Coordinator { return Coordinator(self) } class Coordinator: NSObject, VNDocumentCameraViewControllerDelegate { let parent: ScanCardView init(_ parent: ScanCardView) { self.parent = parent } func documentCameraViewController(_ controller: VNDocumentCameraViewController, didFinishWith scan: VNDocumentCameraScan) { print("Escaneo completado, procesando imagen...") guard scan.pageCount &gt; 0, let image = scan.imageOfPage(at: 0).cgImage else { print("No se pudo obtener la imagen del escaneo.") controller.dismiss(animated: true, completion: nil) return } recognizeText(from: image) DispatchQueue.main.async { print("Finalizando proceso OCR y cerrando la cámara.") controller.dismiss(animated: true, completion: nil) } } func documentCameraViewControllerDidCancel(_ controller: VNDocumentCameraViewController) { print("Escaneo cancelado por el usuario.") controller.dismiss(animated: true, completion: nil) } func documentCameraViewController(_ controller: VNDocumentCameraViewController, didFailWithError error: Error) { print("Error en el escaneo: \(error.localizedDescription)") controller.dismiss(animated: true, completion: nil) } private func recognizeText(from image: CGImage) { let request = VNRecognizeTextRequest { (request, error) in guard let observations = request.results as? [VNRecognizedTextObservation], error == nil else { print("Error en el reconocimiento de texto: \(String(describing: error?.localizedDescription))") DispatchQueue.main.async { self.parent.presentationMode.wrappedValue.dismiss() } return } let recognizedStrings = observations.compactMap { observation in observation.topCandidates(1).first?.string } print("Texto reconocido: \(recognizedStrings)") let filteredCoordinates = self.filterValidCoordinates(from: recognizedStrings) DispatchQueue.main.async { print("Coordenadas detectadas después de filtrar: \(filteredCoordinates)") self.parent.scannedCoordinates = filteredCoordinates } } request.recognitionLevel = .accurate let handler = VNImageRequestHandler(cgImage: image, options: [:]) DispatchQueue.global(qos: .userInitiated).async { do { try handler.perform([request]) print("OCR completado y datos procesados.") } catch { print("Error al realizar la solicitud de OCR: \(error.localizedDescription)") } } } private func filterValidCoordinates(from strings: [String]) -&gt; [String: String] { var result: [String: String] = [:] print("Texto antes de filtrar: \(strings)") for string in strings { let trimmedString = string.replacingOccurrences(of: " ", with: "") if parent.useLettersForColumns { let pattern = "^[A-J]\\d{1,2}$" // Letras de A-J seguidas de 1 o 2 dígitos if trimmedString.range(of: pattern, options: .regularExpression) != nil { print("Coordenada válida detectada (letras): \(trimmedString)") result[trimmedString] = "Valor" // Asignación de prueba } } else { let pattern = "^[1-9]\\d{0,1}$" // Solo números, de 1 a 99 if trimmedString.range(of: pattern, options: .regularExpression) != nil { print("Coordenada válida detectada (números): \(trimmedString)") result[trimmedString] = "Valor" } } } print("Coordenadas finales después de filtrar: \(result)") return result } } }

Hi, seems MSL is missing support for a clock() shader instruction available in other graphics APIs like Vulkan or OpenGL for example.. useful for counting cost in number of clock cycles of some code insider shader with much finer granularity than launching a micro kernel with same instructions and measuring cycles cost from CPU.. also useful for MoltenVK to support that extensions.. thanks..

Hello! I have a question about how thread groups work with tile shading. When running "traditional" compute, I get to choose both thread group size and the grid size. However, when using tile shading kernel I only have dispatchThreadsPerTile method - this controls how many threads will be ran in each tile. So far so good, but what about thread groups? The examples in video "Tile Shading on A11" seem to suggest that there will be only one thread group per tile. In the video, [[thread_index_in_threadgroup]] is called "local_id" and it is used to access the image block. I assume this is the default configuration. So when one does the following: Creates MTLRenderPassDescriptor with tileWidth set to W and tileHeight set to H Fires up the tile shading kernel using dispatchThreadsPerTile with MTLSize size = { W, H, 1 } I understand that the result is 1-to-1 mapping between the tile "pixels" and kernel threads. Now, what I would like to do is to have more than one thread group there. I want this for performance reasons: I have a certain compute kernel which I know executes very well with small thread group size. In fact, { 32, 1, 1 } seems to be the fastest. My understanding is that even if I set tile size to 16x16, and so I am executing 256 threads there, there will only be one SIMD group active in a thread group. Meaning that this SIMD group has to execute 8 times over the tile. Is it possible somehow? Or perhaps the limitations of the API are pointing at the limitations of hardware itself, and if I want to execute with SIMD group sized thread groups I have to use "traditional" compute encoder? Will be grateful for help. Michał

Hello, I'm tracking down a bug where useResource doesn't seem to apply proper synchronization when a resource is produced by the render pass then consumed by the compute pass, but when I use MTLFence between the to signal and wait between the render/compute encoders, the artifact goes away. The resource is created with MTLHazardTrackingModeTracked and useResource is called on the compute encoder after the render pass. Metal API Validation doesn't report any warnings/errors. Am I misunderstanding the difference between the two APIs? I dug through the Metal documentation and it looks like useResource should handle synchronization given the resource has MTLHazardTrackingModeTracked but on the other hand, MTLFence should be used to ensure proper synchronization between command encoders. Can someone can clarify the difference between the two APIs and when to use them.

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:

My app is live but the leaderboards still aren’t updating. App was built with unreal engine 5 with blueprints. I have the leaderboard stat info entered into the node for write integer to leaderboard and a node for show platform specific leaderboard. The leaderboards are shown as live on app connect. When I run the app, the Game Center login functions and the leaderboard interface launches as expected but it just lists a group of friends to invite. There are no scores listed and it says number of players 0 even though I have scored on two different devices and accounts. I have the Game Center entitlement added in Xcode. Not sure where else to look.

macOS 15.2, MBP M1, built-in display. The following code produces a line outside the bounds of my clipping region when drawing to CGLayers, to produce a clockwise arc: CGContextBeginPath(m_s.outContext); CGContextAddArc(m_s.outContext, leftX + radius, topY - radius, radius, -startRads, -endRads, 1); CGContextSetRGBStrokeColor(m_s.outContext, col.fRed(), col.fGreen(), col.fBlue(), col.fAlpha()); CGContextSetLineWidth(m_s.outContext, width); CGContextStrokePath(m_s.outContext); Drawing other shapes such as rects or ellipses doesn't cause a problem. I can work around the issue by bringing the path back to the start of the arc: CGContextBeginPath(m_s.outContext); CGContextAddArc(m_s.outContext, leftX + radius, topY - radius, radius, -startRads, -endRads, 1); // add a second arc back to the start CGContextAddArc(m_s.outContext, leftX + radius, topY - radius, radius, -endRads, -startRads, 0); CGContextSetRGBStrokeColor(m_s.outContext, col.fRed(), col.fGreen(), col.fBlue(), col.fAlpha()); CGContextSetLineWidth(m_s.outContext, width); CGContextStrokePath(m_s.outContext); But this does appear to be a bug.

Hello Apple team, I'm working on an iOS AR app using SwiftUI and RealityKit, and I was wondering if the Cinematic API can be used with a RealityKit scene. I’d like to achieve a shallow depth of field while keeping the 3D asset in focus, and vice versa. Thanks!

I’ve added two recurring leaderboards to my app and the user interface for the Game Center leaderboards pops up when expected and it lists the leaderboards but when you click on them it says “Have Fun With Friends” and lists some of my contacts instead of any scores. The status under Apple Connect is “Not Live” and I’m wondering how to activate them. App has been approved for external beta testing. On a related note, on my iPad it doesn’t display correctly, it says “Game Center” at the top but the rest of the UI doesn’t appear, just blackness.

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!

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'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

After watching WWDC 2025 session "Combine Metal 4 machine learning and graphics", I have decided to give it a shot to integrate the latest MTL4MachineLearningCommandEncoder to my existing render pipeline. After a lot of trial and errors, I managed to set up the pipeline and have the app compiled. However, I am now stuck on creating a MTLLibrary with .mtlpackage. Here is the code I have to create a MTLLibrary according the WWDC session https://developer.apple.com/videos/play/wwdc2025/262/?time=550: let coreMLFilePath = bundle.path(forResource: "my_model", ofType: "mtlpackage")! let coreMLURL = URL(string: coreMLFilePath)! do { metalDevice.makeLibrary(URL: coreMLURL) } catch { print("error: \(error)") } With the above code, I am getting error: Error Domain=MTLLibraryErrorDomain Code=1 "Invalid metal package" UserInfo={NSLocalizedDescription=Invalid metal package} What is the correct way to create a MTLLibrary with .mtlpackage? Do I see this error because the .mtlpackage I am using is incorrect? How should I go with debugging this? I'd really appreciate if I could get some help on this as I have been stuck with it for some time now. Thanks in advance!

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 hierarchy: Before exporting for the animation (armature modifier applied), I simply had to store the Model entities and swap them in but now when I export with the Armature Modifier applied, so that animations get exported, the ModelComponent gets flattened to the armature and swapping entities and applying new materials to them is no longer as simple. Here's a demo blend file and usdc export with a setup like mine, having an animated bone to swing a cube and sphere, to be swapped so that only one is visible https://www.dropbox.com/scl/fo/be2q6qcztc83z7c4gj1w0/AMapxWc_ip2KZ8oTOYDUMv8?rlkey=rcdaggcxq06dyen09mw5mqmem&st=bnc0d7j0&dl=0 This is how I'm loading the entity and removing a part, with the demo files import SwiftUI import RealityKit struct SwapDemoView: View { var body: some View { RealityView { content in let camera = PerspectiveCamera() camera.transform.translation = SIMD3(x: 0, y: 0.1, z: 3) guard let root = try? await Entity(named: "simpleSwapDemo") else { fatalError("simpleSwapDemo.usdc is not present") } print(root) // Get initial hierarchy guard let cube = root.findEntity(named: "Cube") else { fatalError("Entity cube doesn't exist") } cube.removeFromParent() // <-- Cube is still visible after removal print(root) // Get hierarchy to confirm removal of cube let resource = root.availableAnimations[0] root.playAnimation(resource.repeat()) content.add(root) content.add(camera) } .background(.white) } } And this is what the entity hierarchy looks like in RealityKit before cube removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 2 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity ⟐ SynchronizationComponent ⟐ Transform And here's the hierarchy after removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform And this is the result: 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.

Hi all, I'm encountering an issue with Metal raytracing on my M5 MacBook Pro regarding Instance Acceleration Structure (IAS). Intersection tests suddenly stop working after a certain point in the sampling loop. Situation I implemented an offline GPU path tracer that runs the same kernel multiple times per pixel (sampleCount) using metal::raytracing. Intersection tests are performed using an IAS. Since this is an offline path tracer, geometries inside the IAS never changes across samples (no transforms or updates). As sampleCount increases, there comes a point where the number of intersections drops to zero, and remains zero for all subsequent samples. Here's a code sketch: let sampleCount: UInt16 = 1024 for sampleIndex: UInt16 in 0..<sampleCount { // ... do { let commandBuffer = commandQueue.makeCommandBuffer() // Dispatch the intersection kernel. await commandBuffer.completed() } do { let commandBuffer = commandQueue.makeCommandBuffer() // Use the intersection test results from the previous command buffer. await commandBuffer.completed() } // ... } kernel void intersectAlongRay( const metal::uint32_t threadIndex [[thread_position_in_grid]], // ... const metal::raytracing::instance_acceleration_structure accelerationStructure [[buffer(2)]], // ... ) { // ... const auto result = intersector.intersect(ray, accelerationStructure); switch (result.type) { case metal::raytracing::intersection_type::triangle: { // Write intersection result to device buffers. break; } default: break; } Observations Encoding both the intersection kernel and the subsequent result usage in the same command buffer does not resolve the problem. Switching from IAS to Primitive Acceleration Structure (PAS) fixes the problem. Rebuilding the IAS for each sample also resolves the issue. Intersections produce inconsistent results even though the IAS and rays are identical — Image 1 shows a hit, while Image 2 shows a miss. Questions Am I misusing IAS in some way ? Could this be a Metal bug ? Any guidance or confirmation would be greatly appreciated.

I have been trying to run an open source Windows executable that I would like to help porting to macOS using the Game Porting Toolkit but I stumbled on an issue quite early in the application lifecycle. It looks like the funtion GetThreadDpiHostingBehavior is missing in USER32.dll Has anyone any idea how to solve that? During the startup, it fails with the following error: TiXL crashed. We're really sorry. The last backup was saved Unknown time to... C:\users\crossover\AppData\Roaming\TiXL\Backup Please refer to Help > Using Backups on what to do next. System.EntryPointNotFoundException: Unable to find an entry point named 'GetThreadDpiHostingBehavior' in DLL 'USER32.dll'. at System.Windows.Forms.ScaleHelper.DpiAwarenessScope..ctor(DPI_AWARENESS_CONTEXT context, DPI_HOSTING_BEHAVIOR behavior) at System.Windows.Forms.ScaleHelper.EnterDpiAwarenessScope(DPI_AWARENESS_CONTEXT awareness, DPI_HOSTING_BEHAVIOR dpiHosting) at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp) at System.Windows.Forms.Control.CreateHandle() at System.Windows.Forms.Application.ThreadContext.get_MarshallingControl() at System.Windows.Forms.WindowsFormsSynchronizationContext..ctor() at System.Windows.Forms.WindowsFormsSynchronizationContext.InstallIfNeeded() at System.Windows.Forms.Control..ctor(Boolean autoInstallSyncContext) at System.Windows.Forms.ScrollableControl..ctor() at System.Windows.Forms.ContainerControl..ctor() at System.Windows.Forms.Form..ctor() at T3.Editor.SplashScreen.SplashScreen.SplashForm..ctor() at T3.Editor.SplashScreen.SplashScreen.Show(String imagePath) in C:\Users\pixtur\dev\tooll\tixl\Editor\SplashScreen\SplashScreen.cs:line 25 at T3.Editor.Program.Main(String[] args) in C:\Users\pixtur\dev\tooll\tixl\Editor\Program.cs:line 111

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

Matchmaking rules https://developer.apple.com/documentation/gamekit/matchmaking-rules?language=objc AppStoreConnectApi rules https://developer.apple.com/documentation/appstoreconnectapi/rules?language=objc ・Environment Unity 6000.2.2f1 XCode 16.1 iOS 26 3 iPhones ・AppStoreConnectApi rules "type": "gameCenterMatchmakingRuleSets", "id": "f6a88caf-85db-42bf-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "co.mygame.RuleSets.GvERandom34", "ruleLanguageVersion": 1, "minPlayers": 3, "maxPlayers": 4 }, "type": "gameCenterMatchmakingRules", "id": "6afa68ce-4d2c-496f-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "GameVersion", "description": "Check Game Version. GvERandom34", "type": "COMPATIBLE", "expression": "requests[0].properties.gameVersion == requests[1].properties.gameVersion", "weight": null }, "type": "gameCenterMatchmakingQueues", "id": "7fb645ef-4eca-4510-xxxxxxxxxxxxxxxxxxxx", "attributes": { "referenceName": "co.mygame.que.GvERandom34", "classicMatchmakingBundleIds": [] }, ・Objective-C Execution code queueName = "co.mygame.que.GvERandom34" keyStr = "gameVersion " valueStr = "1.0" - (void)MatchQueueParamStr1Start:(NSString*)queueName keyStr:(NSString*)keyStr valueStr:(NSString*)valueStr { if (@available(iOS 17.2, tvOS 17.2, macOS 14.2, visionOS 1.1, *) == NO) { DBGLOG(@"MatchQueueParamStr1Start Not support."); return; } self->_matchMakingFlag = YES; self->_matchFinishFlag = NO; self->_myMatch = nil; GKMatchRequest *req = [[GKMatchRequest alloc] init]; if (@available(iOS 17.2, tvOS 17.2, macOS 14.2, visionOS 1.1, *)) { req.queueName = queueName; req.properties = @{keyStr: valueStr}; } [[GKMatchmaker sharedMatchmaker] findMatchForRequest:req withCompletionHandler: ^(GKMatch *match, NSError *error) { if (error) { [self SetupErrorInfo:error descriptionText:@"findMatchForRequest"]; } else if(match) { self->_myMatch = match; self->_myMatch.delegate = self; } self->_matchMakingFlag = NO; self->_matchFinishFlag = YES; }]; } ・ I'm trying to match with three devices. Matching doesn't work. 5 minutes later times out. What's the problem?