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

Hi Apple, In VisionOS, for real-time streaming of large 3D scenes, I plan to create Metal buffers and textures in multiple threads and then use a compute shader on the main thread to copy the Metal resources into RealityKit, minimizing main thread usage. Given that most of RealityKit's default APIs require execution on the main actor (main thread), it is not ideal for streaming data. Is this approach the best way to handle streaming data and real-time rendering? Thank you very much.

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 been working on Swift game which is not yet launched or available for preview. The game works in such a way that it has idle CPU while the user is thinking and sustained max CPU and GPU on as many cores as possible when he makes a move. Rarely, due to OS activity or something else outside of my control (for example when dropping the OS curtain even if for just a bit then remove it), the game or some of its threads are moved to efficiency cores which results in major stuttering which persists precisely until the game is idle again at which point the game is moved back on performance cores - but if the player keeps making moves the stuttering simply won't go away and so I guess compuptation is locked onto efficiency cores. The issue does not reproduce on MacCatalyst on Intel. How do I tell Swift to avoid efficiency cores? BTW Swift and SceneKIT have AMAZING performance especially when compared to others.

Hello! I'm currently porting a videogame console emulator to iOS and I'm trying to make the renderer (tested on MacOS) work on iOS as well. The emulator core is written in C++ and uses metal-cpp for rendering, whereas the iOS frontend is written in Swift with SwiftUI. I have an Objective-C++ bridging header for bridging the Swift and C++ sides. On the Swift side, I create an MTKView. Inside the MTKView delegate, I run the emulator for 1 video frame and pass it the view's backing layer for it to render the final output image with. The emulator runs and returns, but when it returns I get a crash in Swift land (callstack attached below), inside objc_release, which indicates I'm doing something wrong with memory management. My bridging interface (ios_driver.h): #pragma once #include <Foundation/Foundation.h> #include <QuartzCore/QuartzCore.h> void iosCreateEmulator(); void iosRunFrame(CAMetalLayer* layer); Bridge implementation (ios_driver.mm): #import <Foundation/Foundation.h> extern "C" { #include "ios_driver.h" } <...> #define IOS_EXPORT extern "C" __attribute__((visibility("default"))) std::unique_ptr<Emulator> emulator = nullptr; IOS_EXPORT void iosCreateEmulator() { ... } // Runs 1 video frame of the emulator and IOS_EXPORT void iosRunFrame(CAMetalLayer* layer) { void* layerBridged = (__bridge void*)layer; // Pass the CAMetalLayer to the emulator emulator->getRenderer()->setMTKLayer(layerBridged); // Runs the emulator for 1 frame and renders the output image using our layer emulator->runFrame(); } My MTKView delegate: class Renderer: NSObject, MTKViewDelegate { var parent: ContentView var device: MTLDevice! init(_ parent: ContentView) { self.parent = parent if let device = MTLCreateSystemDefaultDevice() { self.device = device } super.init() } func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {} func draw(in view: MTKView) { var metalLayer = view.layer as! CAMetalLayer // Run the emulator for 1 frame & display the output image iosRunFrame(metalLayer) } } Finally, the emulator's render function that interacts with the layer: void RendererMTL::setMTKLayer(void* layer) { metalLayer = (CA::MetalLayer*)layer; } void RendererMTL::display() { CA::MetalDrawable* drawable = metalLayer->nextDrawable(); if (!drawable) { return; } MTL::Texture* texture = drawable->texture(); <rest of rendering follows here using the drawable & its texture> } This is the Swift callstack at the time of the crash: To my understanding, I shouldn't be violating ARC rules as my bridging header uses CAMetalLayer* instead of void* and Swift will automatically account for ARC when passing CoreFoundation objects to Objective-C. However I don't have any other idea as to what might be causing this. I've been trying to debug this code for a couple of days without much success. If you need more info, the emulator code is also on Github Metal renderer: https://github.com/wheremyfoodat/Panda3DS/blob/ios/src/core/renderer_mtl/renderer_mtl.cpp#L58-L68 Bridge implementation: https://github.com/wheremyfoodat/Panda3DS/blob/ios/src/ios_driver.mm Bridging header: https://github.com/wheremyfoodat/Panda3DS/blob/ios/include/ios_driver.h Any help is more than appreciated. Thank you for your time in advance.

Hello, I am trying to read video frames using AVAssetReaderTrackOutput. Here is the sample code: //prepare assets let asset = AVURLAsset(url: some_url) let assetReader = try AVAssetReader(asset: asset) guard let videoTrack = try await asset.loadTracks(withMediaCharacteristic: .visual).first else { throw SomeErrorCode.error } var readerSettings: [String: Any] = [ kCVPixelBufferIOSurfacePropertiesKey as String: [String: String]() ] //check if HDR video var isHDRDetected: Bool = false let hdrTracks = try await asset.loadTracks(withMediaCharacteristic: .containsHDRVideo) if hdrTracks.count > 0 { readerSettings[AVVideoAllowWideColorKey as String] = true readerSettings[kCVPixelBufferPixelFormatTypeKey as String] = kCVPixelFormatType_420YpCbCr10BiPlanarFullRange isHDRDetected = true } //add output to assetReader let output = AVAssetReaderTrackOutput(track: videoTrack, outputSettings: readerSettings) guard assetReader.canAdd(output) else { throw SomeErrorCode.error } assetReader.add(output) guard assetReader.startReading() else { throw SomeErrorCode.error } //add writer ouput settings let videoOutputSettings: [String: Any] = [ AVVideoCodecKey: AVVideoCodecType.hevc, AVVideoWidthKey: 1920, AVVideoHeightKey: 1080, ] let finalPath = "//some URL oath" let assetWriter = try AVAssetWriter(outputURL: finalPath, fileType: AVFileType.mov) guard assetWriter.canApply(outputSettings: videoOutputSettings, forMediaType: AVMediaType.video) else { throw SomeErrorCode.error } let assetWriterInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoOutputSettings) let sourcePixelAttributes: [String: Any] = [ kCVPixelBufferPixelFormatTypeKey as String: isHDRDetected ? kCVPixelFormatType_420YpCbCr10BiPlanarFullRange : kCVPixelFormatType_32ARGB, kCVPixelBufferWidthKey as String: 1920, kCVPixelBufferHeightKey as String: 1080, ] //create assetAdoptor let assetAdaptor = AVAssetWriterInputTaggedPixelBufferGroupAdaptor( assetWriterInput: assetWriterInput, sourcePixelBufferAttributes: sourcePixelAttributes) guard assetWriter.canAdd(assetWriterInput) else { throw SomeErrorCode.error } assetWriter.add(assetWriterInput) guard assetWriter.startWriting() else { throw SomeErrorCode.error } assetWriter.startSession(atSourceTime: CMTime.zero) //prepare tranfer session var session: VTPixelTransferSession? = nil guard VTPixelTransferSessionCreate(allocator: kCFAllocatorDefault, pixelTransferSessionOut: &session) == noErr, let session else { throw SomeErrorCode.error } guard let pixelBufferPool = assetAdaptor.pixelBufferPool else { throw SomeErrorCode.error } //read through frames while let nextSampleBuffer = output.copyNextSampleBuffer() { autoreleasepool { guard let imageBuffer = CMSampleBufferGetImageBuffer(nextSampleBuffer) else { return } //this part copied from (https://developer.apple.com/videos/play/wwdc2023/10181) at 23:58 timestamp let attachment = [ kCVImageBufferYCbCrMatrixKey: kCVImageBufferYCbCrMatrix_ITU_R_2020, kCVImageBufferColorPrimariesKey: kCVImageBufferColorPrimaries_ITU_R_2020, kCVImageBufferTransferFunctionKey: kCVImageBufferTransferFunction_SMPTE_ST_2084_PQ, ] CVBufferSetAttachments(imageBuffer, attachment as CFDictionary, .shouldPropagate) //now convert to CIImage with HDR data let image = CIImage(cvPixelBuffer: imageBuffer) let cropped = "" //here perform some actions like cropping, flipping, etc. and preserve this changes by converting the extent to CGImage first: //this part copied from (https://developer.apple.com/videos/play/wwdc2023/10181) at 24:30 timestamp guard let cgImage = context.createCGImage( cropped, from: cropped.extent, format: .RGBA16, colorSpace: CGColorSpace(name: CGColorSpace.itur_2100_PQ)!) else { continue } //finally convert it back to CIImage let newScaledImage = CIImage(cgImage: cgImage) //now write it to a new pixelBuffer let pixelBufferAttributes: [String: Any] = [ kCVPixelBufferCGImageCompatibilityKey as String: true, kCVPixelBufferCGBitmapContextCompatibilityKey as String: true, ] var pixelBuffer: CVPixelBuffer? CVPixelBufferCreate( kCFAllocatorDefault, Int(newScaledImage.extent.width), Int(newScaledImage.extent.height), kCVPixelFormatType_420YpCbCr10BiPlanarFullRange, pixelBufferAttributes as CFDictionary, &pixelBuffer) guard let pixelBuffer else { continue } context.render(newScaledImage, to: pixelBuffer) //context is a CIContext reference var pixelTransferBuffer: CVPixelBuffer? CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pixelTransferBuffer) guard let pixelTransferBuffer else { continue } // Transfer the image to the pixel buffer. guard VTPixelTransferSessionTransferImage(session, from: pixelBuffer, to: pixelTransferBuffer) == noErr else { continue } //finally append to taggedBuffer } } assetWriterInput.markAsFinished() await assetWriter.finishWriting() The result video is not in correct color as the original video. It turns out too bright. If I play around with attachment values, it can be either too dim or too bright but not exactly proper as the original video. What am I missing in my setup? I did find that kCVPixelFormatType_4444AYpCbCr16 can produce proper video output but then I can't convert it to CIImage and so I can't do the CIImage operations that I need. Mainly cropping and resizing the CIImage

https://developer.apple.com/documentation/arkit/arkit_in_ios/specifying_a_lighting_environment_in_ar_quick_look How can I disable it? or at least use a custom texture that's just black? I don't see the purpose of having the real-time environment probe that captures IBL, but always add this fake studio IBL that you can't remove...

Hi, I am working with a large project. We are compiling each material to its own .metallib. They all include many common files full of inline functions. Finally we link it all together at the end with a single big pathtrace kernel. Everything works as expected, however the compile times have gotten completely out of hand and it takes multiple minutes to compile at runtime (to native code). I have gathered that I can do this offline by using metal-tt however if I am wondering if there is a way to reduce the compile times in such a scenario, and how to investigate what the root cause of the problem is. I suspect it could have to do with the fact that every materials metallib contains duplications of all the inline functions. Any ideas on how to profile and debug this? Thanks, Rasmus

When running on my iPhone SE3 under IOS 18.4.1, achievement banners show as expected. The same code running on my iPad Air2 under IOS 15.8.4, achievement banners do not show, but they are accepted (as shown in the GameCenterViewController). The banners also don't show when running the simulator under iPhone 16 Pro Max under IOS 18.2 or simulator under iPhone SE3 under IOS 18.3. I haven't tried others. [Note that I clear the achievements each run during test so that I can duplicate this]

RealityKit spatial audio crackles and pops on iOS 26.0 beta 5. It works correctly on iOS 18.6 and visionOS 26.0 beta 5. The APIs used are AudioPlaybackController, Entity.prepareAudio, Entity.play Videos of the expected and observed behavior are attached to the feedback FB19423059. The audio should be a consistent, repeating sound, but it seems oddly abbreviated and the volume varies unexpectedly. Thank you for investigating this issue.

Hello If you add a ModelEntity to a world inside a portal, the drawing of the model will be occluded properly to the portal bounds. However the invisible shape of the InputTargetComponent and CollisionComponent are not occluded. They are able to cross the portal, and if you have gestures on your ModelEntity you can trigger them in areas outside the portal bounds. This happens even if the ModelEntity has no PortalCrossingComponent.

The “explore spatial accessory input on visionOS” presentation from WDC25 interests me. I bought both the MUSE Logitech stylus and the PS VR2 sense controllers to try out with the sculpting app presented by the author, engineer Amanda Han. Unfortunately the app itself was not included. Could the app be made available for downloading as well as the Xcode project? I appreciate any assistance the author and your team could provide. Thank you.

after launching a nearby exoerience on quick look or inside our app, all the user in the group watch sometimes teh model blinking abd becoming transparet... ... just one user hasnt the issue, either the one who launched shareplay or the user who force align the immersive space in front weird

Hi all, I've developed some code that enables an arcball camera interaction with my scene. I've done this using components and systems. The implementation feels a bit messy as I've got gesture code on my realityView, and then a bunch of other code that uses those gesture inputs in my component and system. Is there a demo app, or some example code that shows a nice way to encapsulate these things in to one item for custom cameras, something like Apple's .realityViewCameraControls(.orbit) If not can anyone recommend an approach to take?

So, I'm done with GPTK and decided to delete it. The only thing I installed was brew -v install apple/apple/game-porting-toolkit and the external libraries from the ditto command. Now, I tried to remove it, but even after brew remove game-porting-toolkit brew autoremove all of the dependencies installed with brew are still there. The most obvious was game-porting-toolkit-compiler, but even after removing this there are so many libraries that are now orphaned and it's just impossible to manually identify those. Is there a way or is the easiest way to simply uninstall Homebrew completely and reinstall it again?

Description: I'm developing an AR effect using SceneKit and applying a transparent material to a face mesh. However, I'm facing an issue where the front faces of the mesh overlap each other, causing incorrect rendering. Problem: The front faces of the mesh overlap with each other when transparency is applied. This causes areas like the cheeks to be visible through the nose, even though they should be occluded. Expected Behavior: The material should behave as if it were opaque to itself—that is, overlapping front faces should be occluded properly, while still allowing transparency for background elements. Actual Behavior: The mesh renders its own front faces incorrectly, making parts of the face visible through others when they should be blocked. What I Have Tried: testMaterial.writesToDepthBuffer = true testMaterial.readsFromDepthBuffer = true Question: 👉 How can I prevent SceneKit's transparent material from rendering overlapping front faces? 👉 Is there a way to force SceneKit to treat its own mesh as opaque for itself while still being transparent to the background? 👉 Does SceneKit support a proper depth pre-pass or an equivalent to Unity’s ZWrite shaders to solve this issue? Attached screenshots demonstrate the problem visually. Any help would be greatly appreciated! 🚀

我们想在游戏类 App 内接入 Game Center。用户可以在游戏内创建多个角色，若用户在游戏内创建了2个角色：角色1、角色2，请问： 当用户将角色1与 Game Center 绑定后，数据将上报至 Game Center。此时玩家想要将角色1与 Game Center 解除绑定，解绑后，再将角色2与 Game Center 绑定。那么这时角色1的数据是留存在 Game Center 中，还是将被移除？

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

I have code that captures a window and displays a cropped image. The problem is 2 fold. Kit doesn't seem to allow to modify stop and recapture image in window mode to capture a portion of the screen. So this makes me having to crop and display the cropped image via a published variable. This all works find. But seems to stop after some time. Using an M1 16gig ram. program is taking less than 100meg of mem with 40-70%cpu as the crow flies. printing captured success in debug mode and sometimes frame isn't valid so guarding against it. any ideas on how to improve my strategy?

I am trying to use the SVGF denoiser to denoise my ray traced shadows (and also other textures later). I do get a smoothed image, but with wonky denoising. I need the depth-normal textures and motion textures for the SVGF and assume that these are badly filled in my case. However, neither in the above linked documentation nor in the WWDC19 video I find how they should be defined. I am looking to answers to: Is depth in red or alpha channel for the depth-normal texture? Are the normals in screen space? Is depth linear? Is it distance or z coordinate in view space? Or even logarithmically scaled or something else? Are the motion vectors supposed to be in pixels per frame? What is the orientation of the axis? Is y up or down? Are there are other restrictions on the formats? Also the linked code did not help me (I have not found any SVGF so far; also all the code is in Objective-C++, not Swift, but that's a different topic). So how should I fill these textures. Can someone point me to the documentation where these kinds of questions are answered?