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.

The sample code just draw a triangle and sample texture. both sample code can draw a correct triangle and sample texture as expected. there are no error message from terminal. Sample code using constexpr Sampler can capture and replay well. Sample code using a argumentTable to bind a MTLSamplerState was crashed when using Metal capture and replay on Xcode. Here are sample codes. Sample Code Test Environment: M1 Pro MacOS 26.3 (25D125) Xcode Version 26.2 (17C52) Feedback ID: FB22031701

Setup: MSAA rendering using a memoryless texture as the color attachment (render_image) and a "normal" texture as the resolve attachment (resolve_image). MTL_DEBUG_LAYER / API validation is enabled for this. When trying to add the memoryless texture to a residency set, I get the following error: -[MTLDebugResidencySet validateResource:], line 114: error 'residency sets do not support memoryless resources. Which is as expected and identical to Metal 3. However, if I don't add it to the residency set, I then get the following error when committing to the command queue: -[MTL4DebugCommandQueue commit:count:options:], line 67: error 'Commit With Options Validation Attachment texture (Label: render_image) used in command buffer (at index 0) is not added to any residency set on the command buffer or command queue. So which way around is actually correct in Metal 4? Either way, this makes the use of memoryless textures/attachments impossible right now when validation is enabled. FWIW: when disabling all validation, either way seems to work just fine. Tested on: M1 Max, macOS 26.3, Xcode 26.2 & 26.4b2

I've been using Metal compute shaders for lattice quantum chromodynamics simulations and wanted to share the experience in case others are doing scientific computing on Metal. The workload involves SU(2) matrix operations on 4D lattice grids — lots of 2x2 and 3x3 complex matrix multiplies, reductions over lattice sites, and nearest-neighbor stencil operations. The implementation bridges a C++ scientific framework (Grid) to Metal via Objective-C++ .mm files, with MSL kernels compiled into .metallib archives during the build. Things that work well: Shared memory on M-series eliminates the CPU↔GPU copy overhead that dominates in CUDA workflows The .metallib compilation integrates cleanly with autotools builds using xcrun Float4 packing for SU(2) matrices maps naturally to MSL vector types Things I'm still figuring out: Optimal threadgroup sizes for stencil operations on 4D grids Whether to use MTLHeap for gauge field storage or stick with individual buffers Best practices for double precision — some measurements need float64 but Metal's double support varies by hardware The application is measuring chromofield flux distributions between static quarks, ultimately targeting multi-quark systems. Production runs are on MacBook Pro M-series and Mac Studio. Code: https://github.com/ThinkOffApp/multiquark-lattice-qcd

Hello everyone! I am trying to wrap a ViewModifier inside a Swift Package that bundles a metal shader file to be used in the modifier. Everything works as expected in the Preview, in the Simulator and on a real device for iOS. It also works in Preview and in the Simulator for tvOS but not on a real AppleTV. I have tried this on a 4th generation Apple TV running tvOS 26.3 using Xcode 26.2.0. Xcode logs the following: The metallib is processed and exists in the bundle. Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Compiler failed to build request precondition failure: pipeline error: custom_effect-fg2a5cia7fmha4: error: unresolved visible function reference: custom_fn Reason: visible function not loaded Contents of Package.swift: import PackageDescription let package = Package( name: "Test", platforms: [ .iOS(.v17), .tvOS(.v17) ], products: [ .library( name: "Test", targets: [ "Test" ] ) ], targets: [ .target( name: "Test", resources: [ .process("Shaders") ] ), .testTarget( name: "TestTests", dependencies: [ "Test" ] ) ] ) Content of my metal file: #include <metal_stdlib> using namespace metal; [[ stitchable ]] float2 complexWave(float2 position, float time, float2 size, float speed, float strength, float frequency) { float2 normalizedPosition = position / size; float moveAmount = time * speed; position.x += sin((normalizedPosition.x + moveAmount) * frequency) * strength; position.y += cos((normalizedPosition.y + moveAmount) * frequency) * strength; return position; } And my ViewModifier: import MetalKit import SwiftUI extension ShaderFunction { static let complexWave: ShaderFunction = { ShaderFunction( library: .bundle(.module), name: "complexWave" ) }() } extension Shader { static func complexWave(arguments: [Shader.Argument]) -> Shader { Shader(function: .complexWave, arguments: arguments) } } struct WaveModifier: ViewModifier { let start: Date = .now func body(content: Content) -> some View { TimelineView(.animation) { context in let delta = context.date.timeIntervalSince(start) content .visualEffect { view, proxy in view.distortionEffect( .complexWave( arguments: [ .float(delta), .float2(proxy.size), .float(0.5), .float(8), .float(10) ] ), maxSampleOffset: .zero ) } } .onAppear { let paths = Bundle.module.paths(forResourcesOfType: "metallib", inDirectory: nil) print(paths) } } } extension View { public func wave() -> some View { modifier(WaveModifier()) } } #Preview { Image(systemName: "cart") .wave() } Any help is appreciated.

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’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.

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 have this drawing app that I have been working on for the past few years when I have free time. I recently rebuilt the app in Metal to build out other brushes and improve performance, need to render 10000s of lines in realtime. I’m running into this issue trying to create a uniform opacity per path. I have a solution but do not love it - as this is a realtime app and the solution could have some bottlenecks. If I just generate a triangle strip from touch points and do my best to smooth, resample, and handle miters I will always get some overlaps. See: To create a uniform opacity I render to an offscreen texture with blending disabled. I then pre-multiply the color and draw that texture to a composite texture with blending on (I do this per path). This works but gets tricky when you introduce a textured brush, the edges of the texture in the frag shader cut out the line. Pasted Graphic 1.png Solution: I discard below a threshold fragment float4 fragment_line(VertexOut in [[stage_in]], texture2d<float> texture [[ texture(0) ]]) { constexpr sampler s(coord::normalized, address::mirrored_repeat, filter::linear); float2 texCoord = in.texCoord; float4 texColor = texture.sample(s, texCoord); if (texColor.a < 0.01) discard_fragment(); // may be slow (from what I read) return in.color * texColor; } Better but still not perfect. Question: I'm looking for better ways to create a uniform opacity per path. I tried .max blending but that will cause no blending of other paths. Any tips, ideas, much appreciated. If this is too detailed of a question just achieve.

Anyone else unable to download the "Rendering a Scene with Deferred Lighting in C++" (https://developer.apple.com/documentation/metal/rendering-a-scene-with-deferred-lighting-in-c++?language=objc)? I just an error page: Is there another place to download this sample?

Hello I am trying to get thread group memory access in fragment shader. In essence, I would like to have all the fragments in a tile to bitwiseOR some value. My idea was to use simd_or across the SIMD group, then make each SIMD group thread 0 to atomic or the value into thread group memory. Finally very first thread of the tile would be tasked with writing the value down to texture with write access. Now, I can allocate the thread group memory argument to the fragment function all right. MTLRenderEncoder has setThreadgroupMemoryLength call, which I am using the following way [renderEncoder setThreagroupMemoryLength: 16 offset: 0 atIndex:0] Unfortunately, all I am getting is the following error (runtime assertion) -[MTLDebugRenderCommandEncoder setThreadgroupMemoryLength:offset:atIndex:]:3487: failed assertion Set Threadgroup Memory Length Validation offset + length(16) must be <= threadgroupMemoryLength(0).` What I am doing wrong? How I can get thread group memory in the fragment shader? I know I could use tile shading and compute function but the problem is that here I really like to use fragment stuff. Will be grateful for help.

Hi, seems MSL is missing support for a clock() shader instruction available in other graphics APIs like Vulkan or OpenGL for example.. useful for counting cost in number of clock cycles of some code insider shader with much finer granularity than launching a micro kernel with same instructions and measuring cycles cost from CPU.. also useful for MoltenVK to support that extensions.. thanks..

In the Creating A 3D Application With Hydra Rendering tutorial on the Apple Developer website, on the last step where I execute this command: cmake -S ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ -B ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ I keep getting an error: CMake Error at CMakeLists.txt:5 (include): include could not find requested file: /Users/macuser/USDInstall/bin/pxrConfig.cmake I've tried to follow the instructions as mentioned in the README.md file included in the project files at least 5 times as well as moving the pxrConfig.cmake file around and copying it in different folders, then executed the command and was still unsuccessful into generating the proper file expected to compile and render the HydraPlayer renderer. How do I get cmake to generate the Xcode file to create the HydraPlayer renderer?

Hey, I've been struggling with this for some days now. I am trying to write to a sparse texture in a compute shader. I'm performing the following steps: Set up a sparse heap and create a texture from it Map the whole area of the sparse texture using updateTextureMapping(..) Overwrite every value with the value "4" in a compute shader Blit the texture to a shared buffer Assert that the values in the buffer are "4". I have a minimal example (which is still pretty long unfortunately). It works perfectly when removing the line heapDesc.type = .sparse. What am I missing? I could not find any information that writes to sparse textures are unsupported. Any help would be greatly appreciated. import Metal func sparseTexture64x64Demo() throws { // ── Metal objects guard let device = MTLCreateSystemDefaultDevice() else { throw NSError(domain: "SparseNotSupported", code: -1) } let queue = device.makeCommandQueue()! let lib = device.makeDefaultLibrary()! let pipeline = try device.makeComputePipelineState(function: lib.makeFunction(name: "addOne")!) // ── Texture descriptor let width = 64, height = 64 let format: MTLPixelFormat = .r32Uint // 4 B per texel let desc = MTLTextureDescriptor() desc.textureType = .type2D desc.pixelFormat = format desc.width = width desc.height = height desc.storageMode = .private desc.usage = [.shaderWrite, .shaderRead] // ── Sparse heap let bytesPerTile = device.sparseTileSizeInBytes let meta = device.heapTextureSizeAndAlign(descriptor: desc) let heapBytes = ((bytesPerTile + meta.size + bytesPerTile - 1) / bytesPerTile) * bytesPerTile let heapDesc = MTLHeapDescriptor() heapDesc.type = .sparse heapDesc.storageMode = .private heapDesc.size = heapBytes let heap = device.makeHeap(descriptor: heapDesc)! let tex = heap.makeTexture(descriptor: desc)! // ── CPU buffers let bytesPerPixel = MemoryLayout<UInt32>.stride let rowStride = width * bytesPerPixel let totalBytes = rowStride * height let dstBuf = device.makeBuffer(length: totalBytes, options: .storageModeShared)! let cb = queue.makeCommandBuffer()! let fence = device.makeFence()! // 2. Map the sparse tile, then signal the fence let rse = cb.makeResourceStateCommandEncoder()! rse.updateTextureMapping( tex, mode: .map, region: MTLRegionMake2D(0, 0, width, height), mipLevel: 0, slice: 0) rse.update(fence) // ← capture all work so far rse.endEncoding() let ce = cb.makeComputeCommandEncoder()! ce.waitForFence(fence) ce.setComputePipelineState(pipeline) ce.setTexture(tex, index: 0) let threadsPerTG = MTLSize(width: 8, height: 8, depth: 1) let tgCount = MTLSize(width: (width + 7) / 8, height: (height + 7) / 8, depth: 1) ce.dispatchThreadgroups(tgCount, threadsPerThreadgroup: threadsPerTG) ce.updateFence(fence) ce.endEncoding() // Blit texture into shared buffer let blit = cb.makeBlitCommandEncoder()! blit.waitForFence(fence) blit.copy( from: tex, sourceSlice: 0, sourceLevel: 0, sourceOrigin: MTLOrigin(x: 0, y: 0, z: 0), sourceSize: MTLSize(width: width, height: height, depth: 1), to: dstBuf, destinationOffset: 0, destinationBytesPerRow: rowStride, destinationBytesPerImage: totalBytes) blit.endEncoding() cb.commit() cb.waitUntilCompleted() assert(cb.error == nil, "GPU error: \(String(describing: cb.error))") // ── Verify a few texels let out = dstBuf.contents().bindMemory(to: UInt32.self, capacity: width * height) print("first three texels:", out[0], out[1], out[width]) // 0 1 64 assert(out[0] == 4 && out[1] == 4 && out[width] == 4) } Metal shader: #include <metal_stdlib> using namespace metal; kernel void addOne(texture2d<uint, access::write> tex [[texture(0)]], uint2 gid [[thread_position_in_grid]]) { tex.write(4, gid); }

I'm running into a persistent visual issue while deploying a floral corridor scene to Apple Vision Pro using Unity 6.0 with URP and Metal. The issue only appears on the Vision Pro device — everything looks fine in the Unity Editor. Issue Description When the frame rate drops to around 60–70 FPS, noticeable distortion artifacts appear around the edges of foliage models. It seems like the background meshes (behind the plants) get warped and leak through the edges of the foliage. Although this is most visible around the leaves, even solid objects like standard URP wall or box models show distorted edges when the issue occurs. All the foliage uses Opaque or Alpha Clipping materials. Things I've Tried Changing the foliage materials to Transparent mode —distortion around edges disappears, but using Transparent for a large number of foliage assets is not ideal for performance or sorting complexity. Reducing the number of foliage objects — with only a few plants in the scene and the frame rate staying around 100 FPS, the distortion disappears. However, this isn’t a practical solution for a full environment. Possible Cause? I came across this note in the Unity documentation: "Ensure depth-buffer for each pixel is non-zero - on visionOS, the depth buffer is used for reprojection. To ensure visual effects like skyboxes and shaders are displayed beautifully, ensure that some value is written to the depth for each pixel." Could this be related to the issue? Is it possible that Alpha Clipping with low pixel coverage leads to some pixels not writing to the depth buffer, which then causes problems during Vision Pro’s reprojection or foveated rendering? However, even when I disable Alpha Clipping entirely, the distortion issue still persists, so it may not be solely caused by clipping itself. Project Setup Unity 6.0 (URP) Depth Texture: Enable Using Metal as the graphics backend Running on real Vision Pro hardware (not simulator) Any advice on how to avoid these distortion issues on Vision Pro would be greatly appreciated. Thanks!

hi everyone, 我们发现了一个和Metal相关崩溃。应用中使用了Metal相关的接口，在进行性能测试时，打开了设置-开发者-显示HUD图形。运行应用后，正常展示HUD，但应用很快发生了崩溃，日志主要信息如下： Incident Identifier: 1F093635-2DB8-4B29-9DA5-488A6609277B CrashReporter Key: 233e54398e2a0266d95265cfb96c5a89eb3403fd Hardware Model: iPhone14,3 Process: waimai [16584] Path: /private/var/containers/Bundle/Application/CCCFC0AE-EFB8-4BD8-B674-ED089B776221/waimai.app/waimai Identifier: Version: 61488 (8.53.0) Code Type: ARM-64 Parent Process: ? [1] Date/Time: 2025-06-12 14:41:45.296 +0800 OS Version: iOS 18.0 (22A3354) Report Version: 104 Monitor Type: Mach Exception Exception Type: EXC_BAD_ACCESS (SIGBUS) Exception Codes: KERN_PROTECTION_FAILURE at 0x000000014fffae00 Crashed Thread: 57 Thread 57 Crashed: 0 libMTLHud.dylib esfm_GenerateTriangesForString + 408 1 libMTLHud.dylib esfm_GenerateTriangesForString + 92 2 libMTLHud.dylib Renderer::DrawText(char const*, int, unsigned int) + 204 3 libMTLHud.dylib Overlay::onPresent(id<CAMetalDrawable>) + 1656 4 libMTLHud.dylib CAMetalDrawable_present(void (*)(), objc_object*, objc_selector*) + 72 5 libMTLHud.dylib invocation function for block in void replaceMethod<void>(objc_class*, objc_selector*, void (*)(void (*)(), objc_object*, objc_selector*)) + 56 6 Metal __45-[_MTLCommandBuffer presentDrawable:options:]_block_invoke + 104 7 Metal MTLDispatchListApply + 52 8 Metal -[_MTLCommandBuffer didScheduleWithStartTime:endTime:error:] + 312 9 IOGPU IOGPUNotificationQueueDispatchAvailableCompletionNotifications + 136 10 IOGPU __IOGPUNotificationQueueSetDispatchQueue_block_invoke + 64 11 libdispatch.dylib _dispatch_client_callout4 + 20 12 libdispatch.dylib _dispatch_mach_msg_invoke + 464 13 libdispatch.dylib _dispatch_lane_serial_drain + 368 14 libdispatch.dylib _dispatch_mach_invoke + 456 15 libdispatch.dylib _dispatch_lane_serial_drain + 368 16 libdispatch.dylib _dispatch_lane_invoke + 432 17 libdispatch.dylib _dispatch_lane_serial_drain + 368 18 libdispatch.dylib _dispatch_lane_invoke + 380 19 libdispatch.dylib _dispatch_root_queue_drain_deferred_wlh + 288 20 libdispatch.dylib _dispatch_workloop_worker_thread + 540 21 libsystem_pthread.dylib _pthread_wqthread + 288 我们测试了几个不同的机型，只有iPhone 13 Pro Max会发生崩溃。 Q1：为什么会发生这个崩溃？ Q2：相同的逻辑，为什么仅在iPhone 13 Pro Max机型上出现崩溃？ 期待您的解答。

Hi there, I'm wondering if it's possible under iOS 28 developer beta to enable MetalFX scaling info with '{"MTL_HUD_ENABLED": "1" for my App. This information has been added to Mac, but looks to be absent on iPhone / iPad

When I take a frame capture of my application in Xcode, it shows a warning that reads "Your application created separate command encoders which can be combined into a single encoder. By combining these encoders you may reduce your application's load/store bandwidth usage." In the minimal reproduction case I've identified for this warning, I have two render pipeline states: The first writes to the current drawable, the depth buffer, and a secondary color buffer. The second writes only to the current drawable. Because these are writing to a different set of outputs, I was initially creating two separate render command encoders to handle the draws under each of these states. My understanding is that Xcode is telling me I could only create one, however when I try to do that, I get runtime asserts when attempting to apply the second render pipeline state since it doesn't have a matching attachment configured for the second color buffer or for the depth buffer, so I can't just combine the encoders. Is the only solution here to detect and propagate forward the color/depth attachments from the first state into the creation of the second state? Is there any way to suppress this specific warning in Xcode?

If I compile a compute kernel with a call to texture.read(), it fails with the following error: "Error Domain=AGXMetalG13X Code=3 "Encountered unlowered function call to air.get_read_sampler" UserInfo={NSLocalizedDescription=Encountered unlowered function call to air.get_read_sampler}." This error occurs on both macOS and iOS 26 Beta 5, but not when running on a simulator or in a playground. It does not occur on a macOS Sequoia VM. It occurs whether I use the old metal 3 or new metal 4 compilation method. A workaround would be to use a sampler, but according to the feature tables, all platforms support reading from textures of all formats. Below is a minimal example which produces the error: let device = MTLCreateSystemDefaultDevice()! let library = device.makeDefaultLibrary()! let computeFunction = library.makeFunction(name: "compute_test")! do { let pipeline = try device.makeComputePipelineState(function: computeFunction) debugPrint(pipeline) } catch { debugPrint("Metal 3 failed with error:\n\(error)") } #import <metal_stdlib> using namespace metal; kernel void compute_test(uint2 gid [[thread_position_in_grid]], texture2d<float, access::read> in [[texture(0)]], texture2d<float, access::write> out [[texture(1)]]) { out.write(in.read(gid), gid); } I filed feedback FB19530049.

Hello, I am experiencing an issue with programmatically capturing a GPU trace using MTLCaptureManager. The .gputrace file that is generated appears to be corrupted, and I'm looking for guidance or a solution. Description of the Problem: I am using MTLCaptureManager.sharedCaptureManager to capture a Metal frame and save it to disk. The generated .gputrace file is consistently reported as 0 bytes in size by the file system. Crucially, when I compress this 0-byte .gputrace file into a .zip archive, the resulting archive contains the full, expected data. After unzipping, the file can be opened and viewed correctly in Xcode. However,When inspecting the file's contents using NSFileManager in Objective-C (treating it as a directory), the internal structure is different from a .gputrace file captured directly from Xcode's Metal Debugger. capture in xcode capture in file Finally,When capturing multiple frames programmatically, the first captured frame contains valid buffer data. However, for subsequent frames (starting from the second frame), the corresponding buffer contents are all zero-filled. Frame 1: All MTLBuffer data is correctly captured and populated. Frame 2 and onward: The same MTLBuffer objects are present in the trace, but their contents are entirely 0 (i.e., the data is not captured or is corrupted). In this case, the on-screen display is normal, but the captured frame is incorrect. The frame captured directly in Xcode is also correct. Only the frame captured to a file is abnormal.