Radeon RADV Driver Readied For Vulkan's Upcoming Mesh Shading Extension

As I've written about since last year the Mesa Radeon Vulkan driver "RADV" has been working on experimental mesh shader support and more recently in Mesa Git code around task shaders for RADV have been landing. Timur Kristóf who is contracted by Valve to work on the open-source Linux graphics stack has been working on the mesh/task shader support in preparation for an upcoming cross-vendor Vulkan extension around mesh shading.

For the moment the Vulkan mesh shading support is by way of NVIDIA's NV_mesh_shader extension but it's been said there is a cross-vendor extension coming from the Vulkan API working group to make the implementation more applicable to other hardware vendors / drivers. Mesh shaders combine vertex and primitive processing as a fundamental change to the graphics rendering pipeline.

NVIDIA diagram on the mesh shading pipeline versus the existing pipeline approach.

NVIDIA supported mesh shaders since Turing and AMD does beginning with RDNA2 (Radeon RX 6000 series) GPUs. Intel has also been preparing mesh shaders on Linux for DG2/Alchemist GPUs.

Following all of the recent mesh/task shader work by Timur having landed, he wrote a number of posts on his new blog that outline the effort. See this latest blog post if interested in all the technical details around RADV mesh/task shader support.

While for the moment there is just the NV_mesh_shader extension, the proper Vulkan mesh shader extension should be here quite soon. Timur concluded his latest post with, "It has been officially confirmed that a Vulkan cross-vendor mesh shading extension is coming soon. While I can’t give you any details about the new extension, I think it won’t be a surprise to anyone that it may have been the motivation for my work on mesh and task shaders. Once the new extension goes public, I will post some thoughts about it and a comparison to the vendor-specific NV_mesh_shader extension."