Hello. I have an application that exports a 3D object with vertex color to USDC. I'm using an MDLAsset and its functionality to export to USDC with [asset exportAssetToURL:[NSURL fileURLWithPath:filePath]]. In version 1.3 of the system, everything works correctly. But after updating to version 2.0, the exported object appears white (using the same code). Any suggestions? Thank you very much.

Hello, I’m working with the GameKit API, and I am encountering an issue when submitting a player’s score to a leaderboard at the end of a game. Goal: After submitting the new score to a leaderboard, I want to immediately fetch and display the updated leaderboard that reflects the new score. Problem: After successfully submitting the player’s score, when I fetch the leaderboard, the entries are not updated right away. The fetched leaderboard still shows the outdated player score. Is this delay in updating the leaderboard expected behavior, or am I missing something in my implementation? Steps to Reproduce: Submit the local player’s score to Leaderboard X. On successful submission, fetch the leaderboard entries for Leaderboard X. Expected Result: The fetched leaderboard should reflect the updated player score immediately. Actual Result: The fetched leaderboard shows the outdated score, with no immediate update. As a workaround, I update the leaderboard myself locally, that does the job, but is error-prone and require more efforts.

Hi there, I'm trying to test the "Drawing fully immersive content using Metal" , but when I select Language: Swift, it still shows Objective C code in some sample codes. Please check and update the document Swift Code, thank you.

So I get JPEG data in my app. Previously I was using the higher level NSBitmapImageRep API and just feeding the JPEG data to it. But now I've noticed on Sonoma If I get a JPEG in the CMYK color space the NSBitmapImageRep renders mostly black and is corrupted. So I'm trying to drop down to the lower level APIs. Specifically I grab a CGImageRef and and trying to use the Accelerate API to convert it to another format (to hopefully workaround the issue... CGImageRef sourceCGImage = `CGImageCreateWithJPEGDataProvider(jpegDataProvider,` NULL, shouldInterpolate, kCGRenderingIntentDefault); Now I use vImageConverter_CreateWithCGImageFormat... with the following values for source and destination formats: Source format: (derived from sourceCGImage) bitsPerComponent = 8 bitsPerPixel = 32 colorSpace = (kCGColorSpaceICCBased; kCGColorSpaceModelCMYK; Generic CMYK Profile) bitmapInfo = kCGBitmapByteOrderDefault version = 0 decode = 0x000060000147f780 renderingIntent = kCGRenderingIntentDefault Destination format: bitsPerComponent = 8 bitsPerPixel = 24 colorSpace = (DeviceRBG) bitmapInfo = 8197 version = 0 decode = 0x0000000000000000 renderingIntent = kCGRenderingIntentDefault But vImageConverter_CreateWithCGImageFormat fails with kvImageInvalidImageFormat. Now if I change the destination format to use 32 bitsPerpixel and use alpha in the bitmap info the vImageConverter_CreateWithCGImageFormat does not return an error but I get a black image just like NSBitmapImageRep

I am trying to get a little game prototype up and running using Metal using the metal-cpp libraries where I run everything natively at 120Hz with a coupled renderer using Vsync turned on so that I have the absolute physically minimum input to photon latency possible. // Create the metal view SDL_MetalView metal_view = SDL_Metal_CreateView(window); CA::MetalLayer *swap_chain = (CA::MetalLayer *)SDL_Metal_GetLayer(metal_view); // Set up the Metal device MTL::Device *device = MTL::CreateSystemDefaultDevice(); swap_chain->setDevice(device); swap_chain->setPixelFormat(MTL::PixelFormat::PixelFormatBGRA8Unorm); swap_chain->setDisplaySyncEnabled(true); swap_chain->setMaximumDrawableCount(2); I am using SDL3 just for creating the window. Now when I go through my game / render loop - I stall for a long time on getting the next drawable which is understandable - my app runs in about 2-3ms. m_CurrentContext->m_Drawable = m_SwapChain->nextDrawable(); m_CurrentContext->m_CommandBuffer = m_CommandQueue->commandBuffer()->retain(); char frame_label[32]; snprintf(frame_label, sizeof(frame_label), "Frame %d", m_FrameIndex); m_CurrentContext->m_CommandBuffer->setLabel(NS::String::string(frame_label, NS::UTF8StringEncoding)); m_CurrentContext->m_RenderPassDescriptor[ERenderPassTypeNormal] = MTL::RenderPassDescriptor::alloc()->init(); MTL::RenderPassColorAttachmentDescriptor* cd = m_CurrentContext->m_RenderPassDescriptor[ERenderPassTypeNormal]->colorAttachments()->object(0); cd->setTexture(m_CurrentContext->m_Drawable->texture()); cd->setLoadAction(MTL::LoadActionClear); cd->setClearColor(MTL::ClearColor( 0.53f, 0.81f, 0.98f, 1.0f )); cd->setStoreAction(MTL::StoreActionStore); However my ProMotion display does not reliably run at 120Hz when fullscreen and using the direct to display system - it seems to run faster when windowed in composite which is the opposite of what I would expect. The Metal HUD says 120Hz, but the delay to getting the next drawable and looking at what Instruments is saying tells otherwise. When I profile it, the game loop has completed and is sitting there waiting for the next drawable, but the screen does not want to complete in 8.33ms, so the whole thing slows down for no discernible reason. Also as a game developer it is very strange for the command buffer to actually need the drawable texture free to be allowed to encode commands - usually the command buffers and swapping the front and back render buffers are not directly dependent on each other. Usually you only actually need the render buffer texture free when you want to draw to it. I could give myself another drawable, but because I am completing in less than 3ms, all it would do would be to add another frame of latency. I also looked at the FramePacing example and its behaviour is even worse at having high framerate with low latency - the direct to display is always rejected for some reason. Is this just a flaw in the Metal API? Or am I missing something important? I hope someone can help - the behaviour of the display is baffling.

On macOS, system symbols displays in a SKTexture as expected, with the correct color and aspect ratio. But on iOS they are always displayed in black, and sometimes with slightly wrong aspect ratio. Is there a solution to this problem? import SpriteKit #if os(macOS) import AppKit #else import UIKit #endif class GameScene: SKScene { override func didMove(to view: SKView) { let systemImage = "square.and.arrow.up" let width = 400.0 #if os(macOS) let image = NSImage(systemSymbolName: systemImage, accessibilityDescription: nil)!.withSymbolConfiguration(.init(hierarchicalColor: .white))! let scale = NSScreen.main!.backingScaleFactor image.size = CGSize(width: width * scale, height: width / image.size.width * image.size.height * scale) #else let image = UIImage(systemName: systemImage)!.applyingSymbolConfiguration(.init(pointSize: width))!.applyingSymbolConfiguration(.init(hierarchicalColor: .white))! #endif let texture = SKTexture(image: image) print(image.size, texture.size(), image.size.width / image.size.height) let size = CGSize(width: width, height: width / image.size.width * image.size.height) addChild(SKSpriteNode(texture: texture, size: size)) } }

I am sure others will agree with me on this. I personally don’t like the way the new reactions look. Too many different color for the reactions. I honestly prefer the old grey version for the reactions to text messages. The extra emoji thing is okay but the change in color for the heart, thumbs up and the other reactions are not the best. Auto correct is horrible in this new update by the way

I'll leave this here for anyone who's interested but it is possible to slightly use Windows VR on ARM Mac, right now it's just some demos but I am still working on solutions: https://www.youtube.com/watch?v=qbucnU0dpDo&t=431s&ab_channel=NightSightProductions

Hello, I want to create a painting app for iOS and I saw many examples use a CAShapeLayer to draw a UIBezierPath. As I understand CoreAnimation uses the GPU so I was wondering how is this implemented on the GPU? Or in other words, how would you do it with Metal or OpenGL? I can only think of continuously updating a texture in response to the user's drawing but that would be a very resource intensive operation... Thanks

In my app, I have an ARView that has cameraMode set to nonAR. I occasionally hide the ARView when it is not needed and reveal it again later. While the ARView is hidden, I'd like to pause the animation to save iPhone battery life. I'd also like to do this when I know that animation in my scene has paused and the contents of the view, although still visible, is static. This was possible using SceneKit, but I can't seem to find an equivalent way to do it using RealityKit. At least as of iOS 18, a hidden ARView with an empty scene appears to use approximately 30% of the CPU. How can I pause ARView so that it won't use the battery unnecessarily? Thank you for considering this question.

I'm testing on an iPhone 12 Pro, running iOS 17.5.1. Playing an HDR video with AVPlayer without explicitly specifying a pixel format (but specifying Metal Compatibility as below) gives buffers with the pixel format kCVPixelFormatType_Lossless_420YpCbCr10PackedBiPlanarVideoRange (&xv0). _videoOutput = [[AVPlayerItemVideoOutput alloc] initWithPixelBufferAttributes:@{ (NSString*)kCVPixelBufferMetalCompatibilityKey: @(YES) } I can't find an appropriate metal format to use for these buffers to access the data in a shader. Using MTLPixelFormatR16Unorm for the Y plane and MTLPixelFormatRG16Unorm for UV plane causes GPU command buffer aborts. My suspicion is that this compressed format isn't actually metal compatible due to the lack of padding bytes between pixels. Explicitly selecting kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange (which uses 16 bits per pixel) for the AVPlayerItemVideoOutput works, but I'd ideally like to use the compressed formats if possible for the bandwidth savings. With SDR video, the pixel format is the lossless 8-bit one, and there are no problems binding those buffers to metal textures. I'm just looking for confirmation there's currently no appropriate metal format for binding the packed 10-bit planes. And if that's the case, is it a bug that AVPlayerVideoOutput uses this format despite requesting Metal compatibility?

Hello, This exact question was already asked in this forum (8 years ago) but I can't find a definitive answer: Does Metal allow using the same color texture as both an input and output (color attachment) of a fragment shader? Is the behavior defined somewhere? I believe this results in undefined behavior under both DirectX and OpenGL, so I'd assume the same for Metal, but then why doesn't Metal warn me about this as it does on some many other "misconfigurations"? It also seems to work correctly in my case, as I found out by accident. Would love to get a clarification! Thanks ahead!

I've got an iOS app that is using MetalKit to display raw video frames coming in from a network source. I read the pixel data in the packets into a single MTLTexture rows at a time, which is drawn into an MTKView each time a frame has been completely sent over the network. The app works, but only for several seconds (a seemingly random duration), before the MTKView seemingly freezes (while packets are still being received). Watching the debugger while my app was running revealed that the freezing of the display happened when there was a large spike in memory. Seeing the memory profile in Instruments revealed that the spike was related to a rapid creation of many IOSurfaces and IOAccelerators. Profiling CPU Usage shows that CAMetalLayerPrivateNextDrawableLocked is what happens during this rapid creation of surfaces. What does this function do? Being a complete newbie to iOS programming as a whole, I wonder if this issue comes from a misuse of the MetalKit library. Below is the code that I'm using to render the video frames themselves: class MTKViewController: UIViewController, MTKViewDelegate { /// Metal texture to be drawn whenever the view controller is asked to render its view. private var metalView: MTKView! private var device = MTLCreateSystemDefaultDevice() private var commandQueue: MTLCommandQueue? private var renderPipelineState: MTLRenderPipelineState? private var texture: MTLTexture? private var networkListener: NetworkListener! private var textureGenerator: TextureGenerator! override public func loadView() { super.loadView() assert(device != nil, "Failed creating a default system Metal device. Please, make sure Metal is available on your hardware.") initializeMetalView() initializeRenderPipelineState() networkListener = NetworkListener() textureGenerator = TextureGenerator(width: streamWidth, height: streamHeight, bytesPerPixel: 4, rowsPerPacket: 8, device: device!) networkListener.start(port: NWEndpoint.Port(8080)) networkListener.dataRecievedCallback = { data in self.textureGenerator.process(data: data) } textureGenerator.onTextureBuiltCallback = { texture in self.texture = texture self.draw(in: self.metalView) } commandQueue = device?.makeCommandQueue() } public func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) { /// need implement? } public func draw(in view: MTKView) { guard let texture = texture, let _ = device else { return } let commandBuffer = commandQueue!.makeCommandBuffer()! guard let currentRenderPassDescriptor = metalView.currentRenderPassDescriptor, let currentDrawable = metalView.currentDrawable, let renderPipelineState = renderPipelineState else { return } currentRenderPassDescriptor.renderTargetWidth = streamWidth currentRenderPassDescriptor.renderTargetHeight = streamHeight let encoder = commandBuffer.makeRenderCommandEncoder(descriptor: currentRenderPassDescriptor)! encoder.pushDebugGroup("RenderFrame") encoder.setRenderPipelineState(renderPipelineState) encoder.setFragmentTexture(texture, index: 0) encoder.drawPrimitives(type: .triangleStrip, vertexStart: 0, vertexCount: 4, instanceCount: 1) encoder.popDebugGroup() encoder.endEncoding() commandBuffer.present(currentDrawable) commandBuffer.commit() } private func initializeMetalView() { metalView = MTKView(frame: CGRect(x: 0, y: 0, width: streamWidth, height: streamWidth), device: device) metalView.delegate = self metalView.framebufferOnly = true metalView.colorPixelFormat = .bgra8Unorm metalView.contentScaleFactor = UIScreen.main.scale metalView.autoresizingMask = [.flexibleWidth, .flexibleHeight] view.insertSubview(metalView, at: 0) } /// initializes render pipeline state with a default vertex function mapping texture to the view's frame and a simple fragment function returning texture pixel's value. private func initializeRenderPipelineState() { guard let device = device, let library = device.makeDefaultLibrary() else { return } let pipelineDescriptor = MTLRenderPipelineDescriptor() pipelineDescriptor.rasterSampleCount = 1 pipelineDescriptor.colorAttachments[0].pixelFormat = .bgra8Unorm pipelineDescriptor.depthAttachmentPixelFormat = .invalid /// Vertex function to map the texture to the view controller's view pipelineDescriptor.vertexFunction = library.makeFunction(name: "mapTexture") /// Fragment function to display texture's pixels in the area bounded by vertices of `mapTexture` shader pipelineDescriptor.fragmentFunction = library.makeFunction(name: "displayTexture") do { renderPipelineState = try device.makeRenderPipelineState(descriptor: pipelineDescriptor) } catch { assertionFailure("Failed creating a render state pipeline. Can't render the texture without one.") return } } } My question is simply: what gives?

I'm building an iOS/iPadOS app for iOS 18+ using the new RealityView in SwiftUI. (I may add visionOS, but I'm not focusing on it right now.) The 3D scene I'm rendering is fairly simple (just a few dozen vertices and a couple of textures), and I'd like to render it at 120fps on ProMotion devices if possible. I tried setting CADisableMinimumFrameDurationOnPhone to true in the info plist, but it had no effect. The frame rate in the GPU Report in Xcode stays capped at 60fps, and the gauge even tops out at 60. My question is kind of the opposite of this post, which asks how to limit the frame rate of a RealityView. I'm on Xcode 16 beta 5 on macOS Sonoma and iOS 18.0 beta 6 on my iPhone 15 Pro.

I have created a turn based game using GameKit. Everything is pretty much done, last thing left to do is the turn time out. I am passing GKTurnTimeoutDefault into the timeout argument in: func endTurn(withNextParticipants nextParticipants: [GKTurnBasedParticipant], turnTimeout timeout: TimeInterval, match matchData: Data) However when I check the .timeoutDate property of the GKTurnBasedParticipant participants, the value is always nil. What am I doing wrong? Am I checking the right property or is there another one instead that I don't know about? I have tried passing different values to the timeout parameter but the timeoutDate is always nil. Has anyone successfully implemented a timeout using GKTurnBasedMatch ?

Hi, I'm trying to understand how I can get 3- or 4-channel per-vertex data into the Graph Editor. From my tests, it seems that: the "Geometric Property" node does not give access to 4-channel data, "Geometric Property (vector3)" does not give me access to custom properties besides the ones defined in MaterialX core the "Texture Coordinates" node has a vector4f mode (yay!), but according to MaterialX spec, texcoords must have 2 or 3 channels, and I can't get 4-channel data to show up there either. My assumption so far is that I must be missing some "magic" – for example, do the primvars in a file have to be in a specific order, independent of their names? Or do their names matter? (E.g. convention would be primars:st and primvars:st1 and so on) Unfortunately the forum doesn't allow me to attach any USDZ or ZIP files or GDrive links; if there's a way to share a test file I'm happy to do so!

I'm using RealityKit for a scene with many static and dynamic ModelEntitys simulating physics. When all the entities have simple collision generated from .generateCollisionShapes I don't see any issues, but for some entities I need much more complex and accurate collision. For this I've been using ShapeResource.generateStaticMesh with the mesh's data (2769 positions, 16272 face indices in this case), which works exactly as desired with a low entity count. However once there are 600+ dynamic entities introducing even one static entity with complex collision will reliably trigger a crash when colliding with one of the dynamic entities (not necessarily on first contact, but inevitably after multiple collisions). If I arbitrarily limit the number of entities to a max of around 500 it seems to prevent the issue from happening, though the likelihood seems to increase with the number of entities so there may be a low probability of it triggering even at 500 entities that I haven't hit while testing. If physx imposes some kind of entity or collision face/shape limit or something like that I'd at least like to know exactly what it is, but ideally there's a way to work around this. Right now my "fix" is just arbitrarily restricting the entity count in a way that limits what my app can do. The crash triggers inside 0x00000001a6790dfc in physx::PxcDiscreteNarrowPhasePCM(physx::PxcNpThreadContext&, physx::PxcNpWorkUnit const&, physx::Gu::Cache&, physx::PxsContactManagerOutput&) () which looks like this (crash line has an -> arrow at the bottom) CoreRE`physx::PxcDiscreteNarrowPhasePCM: ... 0x1a6790df0 <+668>: mov x1, x24 0x1a6790df4 <+672>: bl 0x1a67913d8 ; physx::PxcNpCacheStreamPair::reserve(unsigned int) 0x1a6790df8 <+676>: ldrb w8, [x23] -> 0x1a6790dfc <+680>: str w8, [x0, #0x20]

I wanted to try the new logging feature for Metal but could not get it to work. I modified the PerformingCalculationsOnAGPU example by adding os_log_default.log_debug("Hello thread: %d", index); to log the current thread id. But never saw any messages neither in the console nor in Xcode. I also added the -fmetal-enable-logging flag. I am running the Sequoia release candidate 15.0 (24A335) on M1 Max and Xcode 16.0 (16A242). What am I missing?

We’re experiencing an issue with wrong SceneKit hit testing results in iOS 17.2 compared with iOS 16.1 when using the either Metal or OpenGLES2 engines. Tapping on a 3D model to place a SCNNode // pointInScene: tapped point let hitResults = sceneView.hitTest(pointInScene, options: nil) return hitResults.first { $0.node.name?.compare("node_name") == .orderedSame }

What is the best way to display text over images - I'd like the image to fade to white underneath the text so that the text is easier to read since I have no control over the contents of the images. I thought about having a second label behind the actual label with the same text in a slightly larger font and white color. but I'd rather have it be a gradual fading of the image just under the text rather than what looks like 3D text. Any suggestions?