Setting massProperties on a USDZ-loaded entity corrupts its transform (position/scale → NaN) Category: RealityKit / visionOS Environment: visionOS 26.x Summary: Modifying PhysicsBodyComponent.massProperties at runtime on an entity loaded from a .usdz file silently corrupts the entity's transform. The translation and scale components become NaN, while rotation remains valid. The corruption occurs during the next RealityKit scene update cycle (e.g., during an await suspension on the main actor). Steps to Reproduce: Author a .usda file with a RigidBody component including valid m_mass and m_inertia values Load the entity at runtime via Entity(named: "MyEntity.usdz", in: bundle) Read the existing PhysicsBodyComponent, modify massProperties, and set it back: if var physics = entity.components[PhysicsBodyComponent.self] { physics.massProperties = .init( mass: 1.944, inertia: SIMD3<Float>(0.013, 0.026, 0.016), centerOfMass: (position: .zero, orientation: .init()) ) entity.components.set(physics) } Add the entity to the scene Perform any await call (e.g., TextureResource(contentsOf:)) that yields to the main actor, allowing a RealityKit scene update to run Expected: The entity retains its position and scale with the updated mass/inertia values. Actual: The entity's transform becomes corrupted: Transform( scale: SIMD3<Float>(nan, nan, nan), rotation: simd_quatf(real: 1.0, imag: SIMD3<Float>(0.0, 0.0, 0.0)), // ← fine translation: SIMD3<Float>(-nan, -nan, -nan) ) Additional findings from investigation: The entity's physics mode does not matter — corruption occurs even when the entity is .kinematic Creating a new PhysicsBodyComponent(...) and replacing the existing one also triggers the bug Modifying other properties on the same component (linearDamping, angularDamping, material, mode) does not cause corruption — only massProperties triggers it The parent entity's transform remains valid The computed mass/inertia values themselves are valid (finite, positive) The corruption is silent — no error, no warning, no crash from RealityKit itself Workaround: Author mass and inertia values directly in the .usda file and do not modify massProperties at runtime: def RealityKitStruct "massFrame" { float3 m_inertia = (0.02, 0.02, 0.038) float m_mass = 2.5 def RealityKitStruct "m_pose" { } } Other PhysicsBodyComponent properties (damping, material, mode) can safely be modified at runtime.

I'm updating our app to support metal 4, but the metal 4 types don't seem to get recognized when targeting simulator. Is it known if metal 4 will be supported in the near future, or am I setting up the app wrong?

Hey all, I'm building a tile-based puzzle game for iOS and have been experimenting with using SwiftUI for the HUD (score, timer, pause menu, settings sheet) layered on top of a SpriteView that hosts the actual gameplay scene. So far the integration has been smoother than I expected — SpriteView drops cleanly into a ZStack, and I can drive SwiftUI state from the SpriteKit scene via an ObservableObject shared between them. That said, I've run into a few rough edges that I'd love some input on. The biggest one is touch handling: when a SwiftUI overlay (like a semi-transparent pause button) sits over the SpriteView, taps near the edges of the button occasionally get swallowed by the underlying scene, even when the button's hit area looks correct in the view debugger. I've tried .contentShape(Rectangle()) and bumping the frame, which helps but doesn't fully eliminate it. Curious if anyone has landed on a reliable pattern here, especially for transient overlays like toast notifications that need to ignore touches everywhere except on the toast itself. The other thing I'm weighing is animation ownership. Right now, gameplay animations (tile slides, match effects) live in SpriteKit, and HUD animations (score pop, combo counter) live in SwiftUI with withAnimation. It works, but the two animation systems don't share a clock, so when I want a "tile matched → score increment" effect to feel synchronized, I end up dispatching from the SKScene back to the ObservableObject and hoping the frame timing lines up. Has anyone found a cleaner way to coordinate timing across the two, or is this just the cost of mixing the frameworks? Would also love to hear from anyone who has shipped a game with this hybrid setup — any gotchas around Scene Phase transitions, backgrounding, or memory pressure that bit you in production? Thanks!

swift test (SwiftPM CLI) fails to decode RealityKit custom components from USD files, even though entity.components.has(MyComponent.self) returns true. Typed access via entity.components[MyComponent.self] returns nil. This forces projects that use RealityKit custom components to use xcodebuild test exclusively. Minimal repro: github.com/mesqueeb/swiftpm-realitykit-custom-component-repro Repro steps git clone https://github.com/mesqueeb/swiftpm-realitykit-custom-component-repro cd swiftpm-realitykit-custom-component-repro swift test --filter componentsPresentButNotDecodableInSwiftTest Observed ✅ entity.components.has(ReproComponent.self) returns true ❌ entity.components[ReproComponent.self] returns nil Expected If has(...) returns true for a registered custom component, typed lookup should decode and return non-nil. Notes Running the same test via xcodebuild test works correctly The component is properly registered and the USDA file correctly references it This affects any project that relies on custom RealityKit components in tests — there is no swift test workaround Feedback ID: FB22099519 Environment: macOS 15.5, Xcode 16.4, Swift 6.1

I was wondering if there's a method on MacOS to have my application hide a hid device such as a game controller and instead have the receiving game/application see my app's virtual controller? Is this possible via DriverKit or some other form of kernel level coding? On Windows we have a tool known as HidHide that hids a game controller from all other applications. Is it possible to implement such behavior into an app or is that system level?

I've been testing Apple Silicon devices in their desktop configurations on the Mac Studio and now retired Mac Pro and it seems like they're greatly bottlenecked by their clock speeds. For reference here's my testing results. Testing Results: Mac Studio M2 Max • 32GBs RAM • 30 core GPU • 1TB Storage CPU Utilization • 60% • 20W CPU Temperature • 47ºC GPU Utilization • 100% • 20W GPU Temperature • 55ºC Fan Speed • 50% Workload Duration • 2hrs Another point is that the clock speed on the M2 Max's CPU is 3.5 GHz and on the GPU it is 1.44 GHz at max performance. Which the Mac Studio has no trouble pushing. My question is how do I push those clock speeds higher? Cause 1.44 GHz at 55ºC is evidence for extensive headroom. I'm sure there are tools internally for testing the upper limits of the silicon, but it makes no sense why it would be set so low the Mac Studio is at no worries of melting. Is there any way to push the performance of my Mac Studio? FB22713867 - Possibilities of Overclocking Apple Silicon

When using index primitives is there a method to provide the indices using a temp buffer like setVertexBytes? Right now I have to create a temp metal buffer even for a small number of vertices and toss it after rendering using drawIndexedPrimitives.

Greetings! I'm preparing to publish an app in Apple Store. It's a 2D Audio app made in Godot, already published in Google Store.. As we know, OpenGL is considered deprecated since iOS 12 / 2018 .. However given the current state of Metal, or Vulkan integration in Godot, and with the idea of bringing the Best possible experience on iOS.. I'm not completely sure what will be the best API to use as primary option.. -As good as Metal, or even Vulkan work in Godot; the fact of the matter is, each API has its strong and weak points.. -Metal: Native on iOS, fully compliant and supported. However it has two weak points: Initial Compilation Freeze - +5 sec. Performance Hit, (although negligible for final user) app uses 25% more CPU (on my iPhone 12). Battery drain? -Vulkan: In godot, Vulkan > MoltenVk > Metal More complex translation layer, but interestingly gives slightly better Performance than Metal.. Initial Compilation doesn't cause Freeze, because is lazy/delayed and performed while the app is starting. Uses 25% less CPU than Metal and gives slightly more stable Framerate. (iPhone 12) However, given the extra complexity it could be more prone to error, or Compatibility Problems, which are known and have been reported with older iOS devices (iPads come to mind..) Right? -OpenGL: No Initial Compilation Needed Max Performance, No CPU munch Universally supported, (in theory?) works Perfectly on my iPhone 12 with iOS 26.3 and 26.4.2 And all in all, gives the best Performance and user experience. -And that's pretty much the situation! Since the graphics API of choice, will have an effect and directly translate to User experience... what's then the best one? -This will be the first app I Publish on Apple Store, so as you can imagine I want to Comply with Apple as much as possible; and bring iOS users the best possible experience. However each one of the APIs seem to have a negative aspect.. Metal: 5sec Compilation Freeze Vulkan: Compatibility Problems? OpenGL: "Deprecated" In practical terms, right now, OpenGL gives the best Performance, and the best User Experience.. So what to do? -The Android version is published in Google Store in OpenGL Compat mode. Works perfectly. Even tho OpenGL has been Deprecated on iOS for 7+ years, it has survived all along, with no announced removal date from Apple. And it seems to work perfectly and be fully operational up to the latest iOS 26 version.. right? Maybe Apple is maintaining it for stability and compatibility reasons, even if they're no longer actively developing it? Butthee "deprecated" label sounds alarming, as if support could drop any day.. So what will be the best choice in this situation? -Will an app built primarily for OpenGL, (with Metal fallback) be Rejected right away in Apple Store? -Otoh Vulkan (via MoltenVK) could be a middle term solution, second best Performance, no Compilation Freeze.. But yeah, the Compatibility aspect is important; and while considerable improvements have been made in Godot's implementation, the current status or possible outcome is harder to assess.. Both Metal and OpenGL seem safer options in that sense..

Hello, I have a problem where my macOS (Sequoia) Spritekit game spikes delta during the first press of an arrow key. I've test this with a small program, code below: // // GameScene.swift import SpriteKit import GameplayKit class GameScene: SKScene { var lastTime: TimeInterval = 0 override func keyDown(with event: NSEvent) { print("---------------> delta keyDown: \(event.characters!) keyCode: \(event.keyCode)") } override func update(_ currentTime: TimeInterval) { // Called before each frame is rendered print("update begins") let dt: CGFloat if lastTime > 0 { dt = (CGFloat(currentTime - lastTime)) } else { dt = 1.0 / 60.0 } if dt > (1/30) { print("************************************ delta spike ", dt) } lastTime = currentTime print("dt: ", dt) print("update ends") } } Example output: update begins ************************************ delta spike 0.03381687504588626 dt: 0.03381687504588626 update ends update begins dt: 0.016670208307914436 update ends As you can see, when I press left arrow key in this case I get a big delta spike. There's no spike with further presses of the arrow key. Other keys, such as the common W A S D controls for games, do not cause this delta spike.

If you are developing a network game, it is best to use server time as the basis for game time. If you are developing a standalone game, it is best to use the rendering frame count as the basis for game time.

I'm converting my game from SceneKit to RealityKit. It has a SpriteKit overlay that according to Explore advanced rendering with RealityKit 2 I can add with the code below. The code runs fine if the SKScene only contains a SKSpriteNode (see the commented out line), but when I add a SKShapeNode with a fillColor instead, the app crashes with this error: -[MTLDebugRenderCommandEncoder validateCommonDrawErrors:]:5970: failed assertion `Draw Errors Validation MTLDepthStencilDescriptor uses frontFaceStencil but MTLRenderPassDescriptor has a nil stencilAttachment texture MTLDepthStencilDescriptor uses backFaceStencil but MTLRenderPassDescriptor has a nil stencilAttachment texture ' I don't know enough about low-level graphics and stencils yet to figure out a quick solution, so I would appreciate if anyone could share an easy fix or explanation of what's wrong. Thanks! class ViewController: NSViewController { var device: MTLDevice! var renderer: SKRenderer! override func loadView() { let arView = ARView(frame: NSScreen.main!.frame) view = arView arView.renderCallbacks.prepareWithDevice = { [weak self] device in guard let self = self else { return } self.device = device renderer = SKRenderer(device: MTLCreateSystemDefaultDevice()!) let scene = SKScene() let shape = SKShapeNode(rectOf: CGSize(width: 10, height: 10)) shape.fillColor = .red scene.addChild(shape) // scene.addChild(SKSpriteNode(color: .red, size: CGSize(width: 10, height: 10))) renderer.scene = scene } arView.renderCallbacks.postProcess = { [weak self] context in guard let self = self else { return } let encoder = context.commandBuffer.makeBlitCommandEncoder() encoder?.copy(from: context.sourceColorTexture, to: context.targetColorTexture) encoder?.endEncoding() renderer.update(atTime: context.time) let descriptor = MTLRenderPassDescriptor() descriptor.colorAttachments[0].loadAction = .load descriptor.colorAttachments[0].storeAction = .store descriptor.colorAttachments[0].texture = context.targetColorTexture renderer.render(withViewport: CGRect(x: 0, y: 0, width: context.targetColorTexture.width, height: context.targetColorTexture.height), commandBuffer: context.commandBuffer, renderPassDescriptor: descriptor) } } }

I'm building an iOS word game (Gramfall) and no production App Store users can see their own scores on any leaderboard, despite Game Center authentication succeeding and no errors being thrown. The same code works correctly in development and all 6 leaderboard submissions fire "Score submitted" notifications on my dev device. 6 leaderboards in App Store Connect (3 Classic all-time, 3 Recurring monthly) and all are Live Production App Store users: authenticated, scores submitted, no errors — scores never appear Development build: all 6 submissions confirmed via Settings → Developer → Notify About Score Submissions Affected users cannot see their own score on the leaderboard from their own device. This rules out privacy/visibility restrictions as a player should always see their own score. This suggests submissions are either silently failing or being accepted but not recorded in the production Game Center environment. What we have ruled out Leaderboard ID mismatch (Everything in App Store Connect matches) Authentication failure (GKLocalPlayer.local.isAuthenticated is true, app shows "Connected") All 6 leaderboards load with releaseState(rawValue: 1), isHidden: false Account-level restrictions effectively ruled out as it affects all users, not one account endGame() fires correctly, confirmed in dev Questions Is there a known difference in how GKLeaderboard.submitScore behaves between the sandbox and production Game Center environments that could cause silent failures? Is there any way for a submission to return no error yet still not be recorded in production? Code func submitGameResult(timeSeconds: Int, score: Int, longestWordLength: Int) { guard GKLocalPlayer.local.isAuthenticated else { return } Task { do { try await GKLeaderboard.submitScore(timeSeconds, context: 0, player: GKLocalPlayer.local, leaderboardIDs: ["gramfall.lb.time", "gramfall.lb.time.monthly"]) try await GKLeaderboard.submitScore(score, context: 0, player: GKLocalPlayer.local, leaderboardIDs: ["gramfall.lb.score", "gramfall.lb.score.monthly"]) try await GKLeaderboard.submitScore(longestWordLength, context: 0, player: GKLocalPlayer.local, leaderboardIDs: ["gramfall.lb.longestword", "gramfall.lb.longestword.monthly"]) } catch { print("[GameCenter] submitGameResult failed: \(error)") } } }

I’m trying to use MTL4FXTemporalDenoisedScaler, and I’m seeing a crash during initialization even with a very simple sample app. I created a minimal sample here: https://github.com/tatsuya-ogawa/MetalFXInitExample The exception is: NSException: "-[AGXG16XFamilyHeap baseObject]: unrecognized selector sent to instance ..." What I found is: • This works: descriptor.makeTemporalDenoisedScaler(device: device) • This crashes: descriptor.makeTemporalDenoisedScaler(device: device, compiler: metal4Compiler) So the issue seems to happen only with the Metal4FX version. For testing, I’m using an iPhone 15 Pro. According to the Metal Feature Set Tables, MetalFX denoised upscaling should be supported on Apple9 and later, so I believe the device itself should meet the requirements. Reference: https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf Has anyone seen this before, or knows what might be causing it? I’d appreciate any advice. Thanks.

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)

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!

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'm new to graphics and game design and I just wanted to know if a compute pipeline could be as efficient as a render pipeline for rasterization and an explanation on how and why. Also is it possible to manually perform rasterization with a render pipeline as in manipulate individual pixel data in a metal texture yourself but do it with a render pipeline?

I think if your buffer is less than 4k its recommended to use setVertexBytes, the question I have is can I keep hammering on setVertexBytes as the primary method to issue multiple draw calls within a render buffer and rely on Metal to figure out how to orphan and replace the target buffer? A lot of the primitives I am drawing are less than 4k and the process of wiring down larger segments of memory for individual buffers for each draw primitive call seems to be a negative. And it's just simpler to copy, submit and forget about buffer synchronization.

Death Stranding 2: On the Beach (v1.0.48.0, Steam) crashes during rendering initialization when running through CrossOver 26 with D3DMetal 3.0 on an Apple M2 Max Mac Studio running macOS Sequoia. The game successfully initializes Streamline, NVAPI, DLSS (Result::eOk), DLSSG (Result::eOk), Reflex, and XeSS — all subsystems report success. The crash occurs immediately after, during rendering pipeline creation, before the game reaches NXStorage initialization or window creation. Minidump analysis confirms the crash is an access violation (0xc0000005) at DS2.exe+0x67233d, writing to address 0x0. RAX=0x0 (null pointer being dereferenced), R12=0xFFFFFFFFFFFFFFFF (error/invalid handle return). The game appears to call a D3D12 API — likely CheckFeatureSupport or a pipeline state creation function — that D3DMetal acknowledges as supported but returns null or invalid data for. The game trusts the response and dereferences the null pointer. Two other Nixxes titles using the same engine and D3DMetal setup run without issue: Spider-Man 2 (~50 FPS) and Horizon Zero Dawn Remastered (~34 FPS). DS2 uses newer technology versions (DLSS 4, FSR 4, XeSS 2) and a newer DirectX 12 Agility SDK, which likely queries D3D12 features that D3DMetal does not yet fully implement. The crash also reproduces when D3DMetal reports as AMD vendor (1002) instead of NVIDIA (10de), crashing at the same executable offset, confirming it is a D3D12 feature reporting gap in D3DMetal rather than a vendor-specific issue. How To Reproduce Install Crossover 26+ on MacOS 26.4 Install Steam and download Death Stranding 2 Run Death Stranding 2 and check logs after crash in Documents\DEATH STRANDING 2 ON THE BEACH Feedback Requests FB22285513 — Game Porting Toolkit 3 issue with Modern Pipeline Creation

I am new to RealityKit and Metal and I am building a RealityKit app that renders a procedural LowLevelMesh road. But the left and right side of the road is a complete green terrain mesh object and it doesn't look great. What I want is to add some rocks, tall trees and dence bushes (or weed) to make it look like the player is in the woods. But when I add many of those objects then the performance drains. What is the best approach to fill background empty spaces in the scene?