Render advanced 3D graphics and perform data-parallel computations using graphics processors using Metal.

Metal Documentation

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Best Way to Use MetalFX in Unreal Engine 5.7 for macOS Port?
Hi everyone, We’re currently porting a high-fidelity AA+ PC title built on Unreal Engine 5.7 to macOS (Apple Silicon), and we’re looking for guidance from anyone with experience in this area. At the moment, the game is already runnable on Mac, but not yet at a playable level — we’re seeing performance around 10–15 FPS on an M4 device. We’re actively analyzing and defining the work needed to reach production-quality performance on macOS. One of the key areas we’re exploring is leveraging MetalFX to improve frame rate. However, it seems there’s no official MetalFX plugin or direct integration available for Unreal Engine. Has anyone here successfully integrated MetalFX into a UE5 rendering pipeline, or found a recommended approach to do so? Any insights on best practices, workflows, or references (docs, samples, etc.) would be greatly appreciated. Thanks in advance!
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Missing DirectX Calls for Tearing and Depth Bound Test in D3DMetal and GPTK 3
I want to address the missing or incomplete DirectX calls from D3DMetal and Game Porting Toolkit 3. These missing calls have in part caused issue with our porting process and we are reconsidering. Missing or Incomplete Calls DXGI_FEATURE_PRESENT_ALLOW_TEARING — IDXGIFactory5::CheckFeatureSupport — this calls has to do with how VSync is handled and some modern games require it to initialize. Currently D3DMetal return 0 maybe by design but most likely because it’s not integrated. Adding a stub that returns 1 can fix this. I’m my use case I simply Noped the check and forced it to continue. D3D12_FEATURE_D3D12_OPTIONS2.DepthBoundsTestSupported — this call is also not present. Which causes games to not initialize rendering. Thankfully this was fixed by once again skipping the check. But this is essential for water rendering. This could be one reason currently water is not rendering in our game. IDXGIOutput6::GetDesc1().ColorSpace — returns DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709 (SDR) on external HDR compatible displays. We were able to fix this by forcing HDR to be enabled. It should return HDR support. These calls may exist but they need to be updated to return the correct values. Specifically for depth bound test you can reference MoltenVK which sets it up on top of Metal since it’s not a native feature. The water issue could be also an issue with how the shaders are compiled. But I’m unable to check because of the closed source nature of GPTK and its debuggers. What is a better way we can debug our game to see why the water isn’t rendering. Does D3DMetal have some debug options or something similar? Feedback Number FB22330617 - Missing DirectX Calls for Tearing and Depth Bound Test in D3DMetal and GPTK 3 We hope these issues are resolved quickly because we were thinking of a simultaneous release with our Windows version, but we can't ship with such large bugs.
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Xcode26 Replay frame broken
Got a broken frame when using Xcode to capture a frame and replay it from a Unity game. It seems like the vertex buffer is broken; I see a bunch of "nan"s in the vertex buffer. However, the game displays correct when running, and it only happend when I upgrade my Xcode and iphone to Xcode26 and IOS26 ios26
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GPTK 3 and D3DMetal issue with Modern Pipeline Creation
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
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741
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Question on setVertexBytes
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.
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Can a compute pipeline be as efficient as a render pipeline for rasterization?
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?
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Cannot load .mtlpackage to MTLLibrary
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!
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429
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MTL4FXTemporalDenoisedScaler initialization
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.
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359
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Using setVertexBytes for index primitives
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.
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450
6d
Best Way to Use MetalFX in Unreal Engine 5.7 for macOS Port?
Hi everyone, We’re currently porting a high-fidelity AA+ PC title built on Unreal Engine 5.7 to macOS (Apple Silicon), and we’re looking for guidance from anyone with experience in this area. At the moment, the game is already runnable on Mac, but not yet at a playable level — we’re seeing performance around 10–15 FPS on an M4 device. We’re actively analyzing and defining the work needed to reach production-quality performance on macOS. One of the key areas we’re exploring is leveraging MetalFX to improve frame rate. However, it seems there’s no official MetalFX plugin or direct integration available for Unreal Engine. Has anyone here successfully integrated MetalFX into a UE5 rendering pipeline, or found a recommended approach to do so? Any insights on best practices, workflows, or references (docs, samples, etc.) would be greatly appreciated. Thanks in advance!
Replies
3
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0
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739
Activity
3w
Missing DirectX Calls for Tearing and Depth Bound Test in D3DMetal and GPTK 3
I want to address the missing or incomplete DirectX calls from D3DMetal and Game Porting Toolkit 3. These missing calls have in part caused issue with our porting process and we are reconsidering. Missing or Incomplete Calls DXGI_FEATURE_PRESENT_ALLOW_TEARING — IDXGIFactory5::CheckFeatureSupport — this calls has to do with how VSync is handled and some modern games require it to initialize. Currently D3DMetal return 0 maybe by design but most likely because it’s not integrated. Adding a stub that returns 1 can fix this. I’m my use case I simply Noped the check and forced it to continue. D3D12_FEATURE_D3D12_OPTIONS2.DepthBoundsTestSupported — this call is also not present. Which causes games to not initialize rendering. Thankfully this was fixed by once again skipping the check. But this is essential for water rendering. This could be one reason currently water is not rendering in our game. IDXGIOutput6::GetDesc1().ColorSpace — returns DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709 (SDR) on external HDR compatible displays. We were able to fix this by forcing HDR to be enabled. It should return HDR support. These calls may exist but they need to be updated to return the correct values. Specifically for depth bound test you can reference MoltenVK which sets it up on top of Metal since it’s not a native feature. The water issue could be also an issue with how the shaders are compiled. But I’m unable to check because of the closed source nature of GPTK and its debuggers. What is a better way we can debug our game to see why the water isn’t rendering. Does D3DMetal have some debug options or something similar? Feedback Number FB22330617 - Missing DirectX Calls for Tearing and Depth Bound Test in D3DMetal and GPTK 3 We hope these issues are resolved quickly because we were thinking of a simultaneous release with our Windows version, but we can't ship with such large bugs.
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6
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3
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415
Activity
3w
Xcode26 Replay frame broken
Got a broken frame when using Xcode to capture a frame and replay it from a Unity game. It seems like the vertex buffer is broken; I see a bunch of "nan"s in the vertex buffer. However, the game displays correct when running, and it only happend when I upgrade my Xcode and iphone to Xcode26 and IOS26 ios26
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1
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0
Views
302
Activity
3w
GPTK 3 and D3DMetal issue with Modern Pipeline Creation
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
Replies
1
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4
Views
741
Activity
3w
Question on setVertexBytes
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.
Replies
2
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0
Views
585
Activity
3w
Can a compute pipeline be as efficient as a render pipeline for rasterization?
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?
Replies
1
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0
Views
385
Activity
3w
Cannot load .mtlpackage to MTLLibrary
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!
Replies
1
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0
Views
429
Activity
3w
MTL4FXTemporalDenoisedScaler initialization
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.
Replies
4
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2
Views
359
Activity
2w
Using setVertexBytes for index primitives
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.
Replies
1
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0
Views
450
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