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.

App Storeにある『浮遊時計 Premium』は1Hzごとか10Hzごと、または3段階以上のリフレッシュレート計測はできますか？

Problem Summary After upgrading to iOS 26.1 and 26.2, I'm experiencing a particle positioning bug in RealityKit where ParticleEmitterComponent particles render at an incorrect offset relative to their parent entity. This behavior does not occur on iOS 18.6.2 or earlier versions, suggesting a regression introduced in the newer OS builds. Environment Details Operating System: iOS 26.1 & iOS 26.2 Framework: RealityKit Xcode Version: 16.2 (16C5032a) Expected vs. Actual Behavior Expected: Particles should render at the position of the entity to which the ParticleEmitterComponent is attached, matching the behavior on iOS 18.6.2 and earlier. Actual: Particles appear away from their parent entity, creating a visual misalignment that breaks the intended AR experience. Steps to Reproduce Create or open an AR application with RealityKit that uses particle components Attach a ParticleEmitterComponent to an entity via a custom system Run the application on iOS 26.1 or iOS 26.2 Observe that particles render at an offset position away from the entity Minimal Code Example Here's the setup from my test case: Custom Component & System: struct SparkleComponent4: Component {} class SparkleSystem4: System { static let query = EntityQuery(where: .has(SparkleComponent4.self)) required init(scene: Scene) {} func update(context: SceneUpdateContext) { for entity in context.scene.performQuery(Self.query) { // Only add once if entity.components.has(ParticleEmitterComponent.self) { continue } var newEmitter = ParticleEmitterComponent() newEmitter.mainEmitter.color = .constant(.single(.red)) entity.components.set(newEmitter) } } } AR Setup: let material = SimpleMaterial(color: .gray, roughness: 0.15, isMetallic: true) let model = Entity() model.components.set(ModelComponent(mesh: boxMesh, materials: [material])) model.components.set(SparkleComponent4()) model.position = [0, 0.05, 0] model.name = "MyCube" let anchor = AnchorEntity(.plane(.horizontal, classification: .any, minimumBounds: [0.2, 0.2])) anchor.addChild(model) arView.scene.addAnchor(anchor) Questions for the Community Has anyone else encountered this particle positioning issue after updating to iOS 26.1/26.2? Are there known workarounds or configuration changes to ParticleEmitterComponent that restore correct positioning? Is this a confirmed bug, or could there be a change in coordinate system handling or transform inheritance that I'm missing? Additional Information I've already submitted this issue via Feedback Assistant(FB21346746)

In a Unity game, if the assetBundle.Unloadinterface is called very frequently during normal gameplay, it can cause the game application's screen to freeze, although the background music continues to play normally. This issue only occurs on iPhone 16 and iPhone 17 models, with no problems on lower-version phones. How can this problem be resolved?

I'm looking to create an effect on iOS that tracks the user's face position with ARKit and shifts nearer/more prominent geometry in the scene around while more "distant" geometry stays fixed to the XY plane - making it look like the geometry on screen "sticks out" I've managed to implement most of this successfully, but it's not perfect when using PerspectiveCameraComponent in RealityKit because as I shift the camera (and change its field of view based on the user's distance) the backplane changes its orientation (it's always orthogonal to camera's direction). I've tried adopting ProjectiveTransformCameraComponent instead. The idea is that the camera shifts around the scene, mirroring the user's head's position, looking at (0,0,0) and the back plane is adjusted to be parallel with the X,Y plane (animation replicated in Blender below). However, I can't manage to set up ProjectiveTransformCameraComponent with an appropriate matrix or update its transform property in a RealityKit System correctly. I also tried setting many simpler projection matrices as described in a number of guides on camera projection matrices on the internet and all I get is a blank view. Does anyone have some guidance on what the projection matrix that ProjectiveTransformCameraComponent expects is meant to look like or how I would go about accomplishing my goal?

Hi! I'd like to share a technical sample app, SKRenderer Demo. This app demonstrates: Setting up SKRenderer Recording SpriteKit scenes to image sequences Recording SpriteKit scenes to video using IOSurface and AVFoundation Applying Core Image filters Exploring SpriteKit's simulation timing and physics determinism Use Case Record SpriteKit simulations as video or images for sharing and creating content. I explored several approaches, including the excellent view.texture(from:crop:) for live recording from SKView. The SKRenderer approach assumes recording happens asynchronously: you capture user interactions as commands during live interaction, then replay those commands through an offline render pass to generate the final output. I hope this helps others working on replay systems, simulation capture, or SpriteKit projects in general!

Turn-based games: 2 players When an opponent declines a game in the Game Center MatchMaker VC, that player sees that they quit, but no message is sent to the listener about that fact. For the person who started the match, their MMVC shows it's their turn again. Why doesn't Game Center end the match?

Hi, I'm trying to set the displayScale environment value for a RealityView, so it renders at 2x instead of 3x on the iPhone, but it seems to have no effect. .environment(\.displayScale, 2.0) Is this expected behavior, or a bug? The reason I want it to render at 2x and not at the default 3x is for game optimization and performance.

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?

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'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

My IOS app generates pdf files. Every time my users open the generated pdf files, the autofill popup jumps out, but my pdf file is NOT for interacting. I'm here to ask if there's a way to mark my pdf files as "not a form", like in metadata or anywhere else?

I'm currently learning Metal. While reading the reference, I came across a strange description. Page 78 in Version 4 Reference (2025-10-25) says: It is legal to call the following set_indices functions to set the indices if the position in the index buffer is valid and if the position in the index buffer is a multiple of 2 (uchar2 overload) or 2 (uchar4 overload). The index I needs to be in the range [0, max_indices). void set_indices(uint I, uchar2 v); void set_indices(uint I, uchar4 v); However, it seems that the uchar4 overload should be multiple of 4. Furthermore, there is no explanation of what these methods actually do. I believe it involves setting two to four consecutive indices at once, but there is no mention of that here. I would like to know if the above understanding is correct.

It's a Broadcast Extension issue: on iOS 26.1 beta the extension never launches—after you tap “Start Broadcast” in the system picker the countdown disappears after 3 s and no broadcast starts, so every live-streaming app（and all other non-system apps that use Broadcast Extension） fails to go live (only the native Photos screen recording still works). Is this a known regression or is a new entitlement required?

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:

Hello Everyone I am new here, I am testing game center integration and using a development build of my IOS game. I have set up a couple of achievements in app store connect, but when I trigger them in the game then they do not unlock or show up. Okay so i am signed into the game center with a sandbox account on a test advice. Is there anything else I need to configure, or do achievements usually only work after the game is released?. I will appreciate any guidance… Thanks in Advance!!!

hi When analyzing our game using Instruments, I've always been confused about the two items "Drawable Present" and "Drawable Presented" in the GPU column. The timing of Drawable Present seems to be when the CPU layer calls commandbuffer:present, rather than when the actual encoding is completed on the GPU. Also, what does drawable presented specifically mean? In our case, when a CPU stall occurs, it appears that the vsync interval changes in the next frame, and a surface that has already been calculated is not displayed. Why is this happening?

I've tried out a ParticleEmitter in Reality Composer Pro to produce a burst of particles that don't move (i.e. speed close to zero). When viewing from different angles, it clearly looks like the particles are rendered exactly in the wrong order, that is, front first and back last. In other words, back particles obscure front particles. I would prefer it the correct way around. I've only tried this interactively in Reality Composer Pro, not programmatically, but I assume I would get the same result. My Reality Composer Pro "File" (zipped): https://gert-rieger-edv.de/Posts/Post-1/RealityParticles.zip Screenshot: Click on the ParticleEmitter object, then on its Play button, then select the Particles tab and click on "Burst" a few times to get a few random particles. Mac Studio 2025 Apple M4 Max macOS 15.7.2 (24G325) Reality Composer Pro Version 2.0 (494.60.2)

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.

I'm trying to use MTLBinaryArchive. I collected a BinaryArchive from one device and used metal-tt to translate it for all supported iPhone devices, ranging from iPhone 7 Plus to iPhone 16. However, this BinaryArchive is quite large, around 1.5GB uncompressed, and about 500MB compressed in the IPA. I'm wondering how to address the size issue. I watched the WWDC 2022 video, which mentioned that the operating system or app installation process would handle compatibility. Does this compatibility support different GPU chips? I tried installing an IPA with a BinaryArchive collected only from an iPhone 12 on an iPhone 13, but the BinaryArchive didn't take effect. I also saw that Apple supports App Thinning. However, it seems that resources in the Asset Catalog cannot be accessed via URL, and creating an MTLBinaryArchive requires a URL. Is it possible for MTLBinaryArchive to be distributed through App Thinning? The WWDC 2022 video also mentioned using the -Os optimization flag to reduce size. Can this give an estimate of how much compression it would achieve? Are there any methods to solve the BinaryArchive size issue without impacting performance?