Vulkan 1.3.226 was released yesterday and it finally includes the cross-vendor VK_EXT_mesh_shader extension. This has definitely been an important moment for me. As part of my job at Igalia and our collaboration with Valve, I had the chance to work reviewing this extension in depth and writing thousands of CTS tests for it. You’ll notice I’m listed as one of the extension contributors. Hopefully, the new tests will be released to the public soon as part of the open source VK-GL-CTS Khronos project.
During this multi-month journey I had the chance to work closely with several vendors working on adding support for this extension in multiple drivers, including NVIDIA (special shout-out to Christoph Kubisch, Patrick Mours, Pankaj Mistry and Piers Daniell among others), Intel (thanks Marcin Ślusarz for finding and reporting many test bugs) and, of course, Valve. Working for the latter, Timur Kristóf provided an implementation for RADV and reported to me dozens of bugs, test ideas, suggestions and improvements. Do not miss his blog post series about mesh shaders and how they’re implemented on RDNA2 hardware. Timur’s implementation will be used in your Linux system if you have a capable AMD GPU and, of course, the Steam Deck.
The extension has been developed with DX12 compatibility in mind. It’s possible to use mesh shading from Vulkan natively and it also allows future titles using DX12 mesh shading to be properly run on top of VKD3D-Proton and enjoyed on Linux, if possible, from day one. It’s hard to provide a summary of the added functionality and what mesh shaders are about in a short blog post like this one, so I’ll refer you to external documentation sources, starting by the Vulkan mesh shading post on the Khronos Blog. Both Timur and myself have submitted a couple of talks to XDC 2022 which have been accepted and will give you a primer on mesh shading as well as some more information on the RADV implementation. Do not miss the event at Minneapolis or enjoy it remotely while it’s being livestreamed in October.