While it’s very rare in recent times for a new OpenGL extension — especially one that is exciting — given the continued great adoption of the modern Vulkan API, in 2025 we are looking at an interesting addition to OpenGL with cross-vendor mesh shading via a proposed GL_EXT_mesh_shader implementation.
Mesh shaders in simple terms are compute shaders able to output triangles on their own. Cross-vendor mesh shading has been available with Vulkan for three years now and going back years prior NVIDIA spearheaded their own OpenGL and Vulkan extensions for mesh shaders when they introduced the hardware capabilities with Turing GPUs.
The GL_NV_mesh_shader extension continues to exist as the NVIDIA vendor prefixed extension for mesh shaders and now a GL_EXT_mesh_shader extension is being proposed by AMD and Mesa developers as a cross-vendor extension.
The proposed GL_EXT_mesh_shader extension is inspired off the NVIDIA GL_NV_mesh_shader as well as Vulkan’s VK_EXT_mesh_shader but more cross-vendor friendly than the NVIDIA-focused implementation:
“This extension provides a new mechanism allowing applications to use two new programmable shader types — the task and mesh shader — to generate collections of geometric primitives to be processed by fixed-function primitive assembly and rasterization logic. When the task and mesh shaders are drawn, they replace the standard programmable vertex processing pipeline, including vertex array attribute fetching, vertex shader processing, tessellation, and the geometry shader processing.”
Qiang Yu of AMD opened this OpenGL Registry pull request this week for introducing the GL_EXT_mesh_shader extension.
This OpenGL mesh shading support was requested by the Nvidium project for Minecraft that uses NVIDIA-only OpenGL extensions for “increasing FPS by a significant amount” due to the performance features like NVIDIA mesh shaders. In turn going back many months there have been requests for OpenGL mesh shader support by the AMD drivers. The issue was also discussed more recently within this Mesa ticket.
Besides the RadeonSI driver implementing this proposed OpenGL extension, there is also interest in seeing the Zink OpenGL-on-Vulkan driver supporting GL_EXT_mesh_shader too. Valve’s Mike Blumenkrantz also commented in that OpenGL pull request:
“I’d like to see the mesa implementation at least well underway before this is released, but I think it’s a great addition to the ecosystem. Bringing cross-vendor support to GL mesh shading will enable things like nvidium to finally run on more platforms.”
And in turn he also put out another one of his blog posts about the matter.