Certain material node graphs can be very expensive to run. This feature aims to produce secondary GPUPass shaders within a GPUMaterial which provide optimal runtime performance. Such optimizations include baking constant data into the shader source directly, allowing the compiler to propogate constants and perform aggressive optimization upfront.
As optimizations can result in reduction of shader editor and animation interactivity, optimized pass generation and compilation is deferred until all outstanding compilations have completed. Optimization is also delayed util a material has remained unmodified for a set period of time, to reduce excessive compilation. The original variant of the material shader is kept to maintain interactivity.
Also adding a new concept to gpu::Shader allowing assignment of a parent shader from which a shader can pull PSO descriptors and any required metadata for asynchronous shader cache warming. This enables fully asynchronous shader optimization, without runtime hitching, while also reducing runtime hitching for standard materials, by using PSO descriptors from default materials, ahead of rendering.
Further shader graph optimizations are likely also possible with this architecture. Certain scenes, such as Wanderer benefit significantly. Viewport performance for this scene is 2-3x faster on Apple-silicon based GPUs.
Authored by Apple: Michael Parkin-White
Ref T96261
Pull Request #104536
Reduces the GLSL to MSL translation stage of shader compilation from 120 ms to 5 ms for complex EEVEE materials. This manifests in faster overall compilations, and faster cache hits for secondary compilations, as the MSL variant is needed as a key.
Startup time is also improved for both first-run and second-run. Note that this change does not affect shader compilation times within the Metal API.
Also disables shader output to disk
Authored by Apple: Michael Parkin-White
Ref T96261
Depends on D16990
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D17033
This patch adds support for compilation and execution of GLSL compute shaders. This, along with a few systematic changes and fixes, enable realtime compositor functionality with the Metal backend on macOS. A number of GLSL source modifications have been made to add the required level of type explicitness, allowing all compilations to succeed.
GLSL Compute shader compilation follows a similar path to Vertex/Fragment translation, with added support for shader atomics, shared memory blocks and barriers.
Texture flags have also been updated to ensure correct read/write specification for textures used within the compositor pipeline. GPU command submission changes have also been made in the high level path, when Metal is used, to address command buffer time-outs caused by certain expensive compute shaders.
Authored by Apple: Michael Parkin-White
Ref T96261
Ref T99210
Reviewed By: fclem
Maniphest Tasks: T99210, T96261
Differential Revision: https://developer.blender.org/D16990
MTLContext provides functionality for command encoding, binding management and graphics device management. MTLImmediate provides simple draw enablement with dynamically encoded data. These draws utilise temporary scratch buffer memory to provide minimal bandwidth overhead during workload submission.
This patch also contains empty placeholders for MTLBatch and MTLDrawList to enable testing of first pixels on-screen without failure.
The Metal API also requires access to the GHOST_Context to ensure the same pre-initialized Metal GPU device is used by the viewport. Given the explicit nature of Metal, explicit control is also needed over presentation, to ensure correct work scheduling and rendering pipeline state.
Authored by Apple: Michael Parkin-White
Ref T96261
(The diff is based on 043f59cb3b)
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D15953
Full support for translation and compilation of shaders in Metal, using
GPUShaderCreateInfo. Includes render pipeline state creation and management,
enabling all standard GPU viewport rendering features in Metal.
Authored by Apple: Michael Parkin-White, Marco Giordano
Ref T96261
Reviewed By: fclem
Maniphest Tasks: T96261
Differential Revision: https://developer.blender.org/D15563
