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! 🚀

Create the QRCode CIFilter<CIBlendWithMask> *f = CIFilter.QRCodeGenerator; f.message = [@"Message" dataUsingEncoding:NSASCIIStringEncoding]; f.correctionLevel = @"Q"; // increase level CIImage *qrcode = f.outputImage; Overlay the icon CIImage *icon = [CIImage imageWithURL:url]; CGAffineTransform *t = CGAffineTransformMakeTranslation( (qrcode.extent.width-icon.extent.width)/2.0, (qrcode.extent.height-icon.extent.height)/2.0); icon = [icon imageByApplyingTransform:t]; qrcode = [icon imageByCompositingOver:qrcode]; Round off the corners static dispatch_once_t onceToken; static CIWarpKernel *k; dispatch_once(&onceToken, ^ { k = [CIWarpKernel kernelWithFunctionName:name fromMetalLibraryData:metalLibData() error:nil]; }); CGRect iExtent = image.extent; qrcode = [k applyWithExtent:qrcode.extent roiCallback:^CGRect(int i, CGRect r) { return CGRectInset(r, -radius, -radius); } inputImage:qrcode arguments:@[[CIVector vectorWithCGRect:qrcode.extent], @(radius)]]; …and this code for the kernel should go in a separate .ci.metal source file: float2 bend_corners (float4 extent, float s, destination dest) { float2 p, dc = dest.coord(); float ratio = 1.0; // Round lower left corner p = float2(extent.x+s,extent.y+s); if (dc.x < p.x && dc.y < p.y) { float2 d = abs(dc - p); ratio = min(d.x,d.y)/max(d.x,d.y); ratio = sqrt(1.0 + ratio*ratio); return (dc - p)*ratio + p; } // Round lower right corner p = float2(extent.x+extent.z-s, extent.y+s); if (dc.x > p.x && dc.y < p.y) { float2 d = abs(dc - p); ratio = min(d.x,d.y)/max(d.x,d.y); ratio = sqrt(1.0 + ratio*ratio); return (dc - p)*ratio + p; } // Round upper left corner p = float2(extent.x+s,extent.y+extent.w-s); if (dc.x < p.x && dc.y > p.y) { float2 d = abs(dc - p); ratio = min(d.x,d.y)/max(d.x,d.y); ratio = sqrt(1.0 + ratio*ratio); return (dc - p)*ratio + p; } // Round upper right corner p = float2(extent.x+extent.z-s, extent.y+extent.w-s); if (dc.x > p.x && dc.y > p.y) { float2 d = abs(dc - p); ratio = min(d.x,d.y)/max(d.x,d.y); ratio = sqrt(1.0 + ratio*ratio); return (dc - p)*ratio + p; } return dc; }

Is there anywhere that the format of error/warning/other? messages that are generated by the Metal compiler are documented?

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

Given a graph with added obstacles I want to make a copy of it. When I make the copy: currentGrath added 20 obstacles. var newGrapth = currentGrath.copy() as? GKObstacleGraph newGrapth2.removeObstacles([newGrapth!.obstacles.first!]) This returns a BAD ACCESS. I don't understand what's going on or what the problem is. If I do this same thing with the main network there is no problem: currentGrath.removeObstacles([currentGrath!.obstacles.first!]) Thanks for the help

Hi, wanted to test if possible to use Mesa3D Dozen driver(Vulkan on D3D12 )+D3DMetal 2b3 to get maybe better Vulkan driver on Wine than default MoltenVK.. this will support Vulkan windows apps via using D3D12Metal.. using vulkan_dzn.dll,dzn_icd.x86_64.json,dxil.dll from x64 folder from: https://github.com/pal1000/mesa-dist-win/releases/download/24.3.0-rc1/mesa3d-24.3.0-rc1-release-msvc.7z using simple vulkaninfo app and running like: wine64 vulkaninfo I get error: [D3DMetal:LOG:2A825] Unsupported API: CheckFeatureSupport, unhandled support query 53 also seems D3DMetal Wine integration on Whisky doesn't expose d3d12core.dll and d3d12.dll like new Agility D3D12 dlls or VKD3D, so getting: MESA: error: Failed to retrieve D3D12GetInterface MESA: error: Failed to load DXCore but anyways seems to try to load the driver as: WARNING: dzn is not a conformant Vulkan implementation, testing use only. full log: MESA: error: Failed to retrieve D3D12GetInterface MESA: error: Failed to load DXCore WARNING: dzn is not a conformant Vulkan implementation, testing use only. [D3DMetal:LOG:2A825] Unsupported API: CheckFeatureSupport, unhandled support query 53 00bc:fixme:dcomp:DCompositionCreateDevice 0000000000000000, {c37ea93a-e7aa-450d-b16f-9746cb0407f3}, 000000000011E328. MESA: error: Failed to load DXCore WARNING: dzn is not a conformant Vulkan implementation, testing use only. [D3DMetal:LOG:2A825] Unsupported API: CheckFeatureSupport, unhandled support query 53 00bc:fixme:dcomp:DCompositionCreateDevice 0000000000000000, {c37ea93a-e7aa-450d-b16f-9746cb0407f3}, 000000000011E578. ERROR: [Loader Message] Code 0 : setup_loader_term_phys_devs: Call to 'vkEnumeratePhysicalDevices' in ICD c:\windows\system32\.\vulkan_dzn.dll failed with error code -3 ERROR: [Loader Message] Code 0 : setup_loader_term_phys_devs: Failed to detect any valid GPUs in the current config ERROR at C:\j\msdk0\build\Khronos-Tools\repo\vulkaninfo\vulkaninfo.h:241:vkEnumeratePhysicalDevices failed with ERROR_INITIALIZATION_FAILED

I have created a simple scene in reality composer (composer not composer pro). It contains just a cube and text item. I convert this to usdz file and load it into a Arkit swift app. Since ios 18/xcode 16 - the "text" element is not displayed at all. The cube is displayed, anchors correctly and can be moved etc.... The output from usdchecker ➜ Desktop usdchecker GKTUHR1.6.3.usdz -v --arkit Opening GKTUHR1.6.3.usdz Checking layer <GKTUHR1.6.3.usdz>. Checking package <GKTUHR1.6.3.usdz> Checking prim </Root>. Checking prim </Root/Scenes>. Checking prim </Root/Scenes/Scene>. Checking prim </Root/Scenes/Scene/Gravity>. Checking prim </Root/Scenes/Scene/sceneGroundPlane>. Checking prim </Root/Scenes/Scene/sceneGroundPlane/physicsMaterial>. Checking prim </Root/Scenes/Scene/Children>. Checking prim </Root/Scenes/Scene/Children/hello>. Checking prim </Root/Scenes/Scene/Children/hello/Generated>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material>. Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>. Checking shader </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>. Checking prim </Root/Scenes/Scene/Children/hello/Children>. Checking prim </Root/Scenes/Scene/Children/Box>. Checking prim </Root/Scenes/Scene/Children/Box/Generated>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Mesh0>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material>. Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>. Checking shader </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>. Checking prim </Root/Scenes/Scene/Children/Box/Children>. Checking prim </Root/Scenes/Scene/Children/Box/PhysicsMaterial_Box>. Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/sceneGroundPlane>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/hello/Generated/Text>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box>. (fails 'MaterialBindingAPIAppliedChecker') Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>. (fails 'MaterialBindingAPIAppliedChecker') Failed!

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?

Hello, I'm creating an app that use PhotogrammetrySession Class to build 3D objects from photographs (https://developer.apple.com/documentation/realitykit/creating-3d-objects-from-photographs). I'm wondering why this class is working only on Pro iphone (12 Pro, 13 Pro, 14 Pro, 15 Pro and 16 Pro) and none non-Pro iPhone. My app does not use Lidar so it's not the problem. I thought it could be power-related but a18 soc from iPhone 16 is more powerful than a14 bionic from iPhone 12 Pro (i could also mention iPhone 13 Pro and iPhone 14 that both have a15 bionic whereas only the first one is compatible). Did I miss something that could explain these restrictions ? Is there any plan to make this class usable by every iPhone enough powerful to run it ? Thanks in advance for answering me

Hi everyone, I've been working with the autoAdjustmentFilters provided by Core Image, which includes filters like CIHighlightShadowAdjust, CIVibrance, and CIToneCurve. However, I’ve noticed that the results differ significantly from the "Auto" enhancement feature in the Photos app. In the Photos app, the Auto function seems to adjust multiple parameters such as contrast, exposure, white balance, highlights, and shadows in a more advanced manner. Is there an API or a framework available that can replicate the more sophisticated "Auto" adjustments as seen in the Photos app? Or would I need to manually combine filters (like CIExposureAdjust, CIWhitePointAdjust, etc.) to approximate this functionality? Any insights or recommendations on how to achieve this would be greatly appreciated. Thank you!

Hello, We are experimenting with Metal to accelerate some peculiar numerical computation. Our workloads are relatively small, so the ability to avoid moving data to and from the GPU's memory is very appealing. However, we are observing higher overhead compared to CUDA, which negates the benefits of avoiding data transfer. In our tests using an empty kernel, CUDA completes in 0.001 ms (Intel i7 10700K, RTX 3080), while Metal's waitUntilCompleted takes 0.12 ms (M2 Max). As we do not have prior experience with Metal, we are wondering if we are using the APIs just fine and this timing is expected, or if there is a way to reduce it. Thank you in advance for any comment! test-metal.cpp

When previewing the recording of gameplay the buttons to exit or save are unclickable behind the top bar clock and Wi-Fi/5G status bar. Which means that you have to quit the game in order to continue. Tested on multiple devices. Does anyone have a solution to this? At the moment we have disabled it altogether for iOS 26 users.

First I get this ar_world_tracking_provider_query_device_anchor_at_timestamp <0x302b9c0a0>: The device_anchor can only be queried when the world tracking provider is running. This seemed to all break with the auto-update to 2.0.1. Simulator runs the code fine. I seem to see an infinite stall here frameLayer.endUpdate() // Pace frames by waiting for the optimal prediction time. try await LayerRenderer.Clock().sleep(until: timing.optimalInputTime, tolerance: nil) // Start submitting the updated frame. frameLayer.startSubmission() <-

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?

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 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

I've been working with ARKit and Metal on the Vision Pro, but I've encountered a slight flickering issue with the mesh rendered using Metal. The flickering tends to occur around the edges of objects or on pixels with high color contrast, and it becomes more noticeable as the distance increases. Is there any way to resolve this issue?

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 ?

I am working on a SceneKit project where I use a CAShapeLayer as the content for SCNMaterial's diffuse.contents to display a progress bar. Here's my initial code: func setupProgressWithCAShapeLayer() { let progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } progressLayer.strokeEnd = progress // Update progress } } } // MARK: - ARSCNViewDelegate func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { progressBarPlane = SCNPlane(width: 0.2, height: 0.2) setupProgressWithCAShapeLayer() let planeNode = SCNNode(geometry: progressBarPlane) planeNode.position = SCNVector3(x: 0, y: 0.2, z: 0) node.addChildNode(planeNode) } This works fine, and the progress bar updates smoothly. However, when I change the code to use a class property (self.progressLayer) instead of a local variable, the rendering starts flickering on the screen: func setupProgressWithCAShapeLayer() { self.progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { [weak self] in var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [weak self] timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } self?.progressLayer?.strokeEnd = progress // Update progress } } } After this change, the progressBarPlane in SceneKit starts flickering while being rendered on the screen. My Question: Why does switching from a local variable (progressLayer) to a class property (self.progressLayer) cause the flickering issue in SceneKit rendering?

I am using SCNTechnique in combination with ARSCNView. The technique is doing so minor post-processing. I have written several filter variant for this post-processing, but I'm facing an issue when with one of the filters/fragment shaders, SCNTechnique discards my output and just presents the plain camera feed on screen instead. This is clearly visible in the Metal pipeline, using the GPU frame debugger. Let me stress that my setup works for 90% of my filters, but not this one and I want to know why. iOS 18.1, iPhone 13 Mini. Xcode 16.1. Encoder 0 & 1 are injected by the system. Render encoder 2 & 3 correspond to my SCNTechnique's render passes: one to manipulate pixel data (darken it in this case) and another to BLIT it back to the main texture. I know the separate buffer is not strictly for this particular operation, but it shouldn't matter. Note that the issue occurs in encoder 4 (not mine but ARKit's). In Render Encoder 4, scn_postprocess_AR_fragment handle my texture (#0, ending in f980) and another from the camera feed (Texture 2). I know this pass is typically used for grain because that's what it used to do before I disabled grain on ARSCNView (+ the buffer still contains grain paramaters). I have other post-processing filters that work just fine. By what magic is ARKit determining to use Texture 2 instead of my Texture 0? Sure, I could keep digging into the minute differences between my shaders to find out which LoC affects how some ARKit shader down the line operates, but it's awfully opaque so far.