2022-4-12 Blender Rendering Meeting


  • Brecht Van Lommel (Blender)
  • Thomas Dinges (Blender)
  • Kevin Dietrich (Blender)
  • Lukas Stockner (Blender)
  • Patrick Mours (NVIDIA)
  • Christophe Hery (Facebook)
  • Olivier Maury (Facebook)
  • Feng Xie (Facebook)
  • Brian Savery (AMD)
  • Stefan Werner (Intel)


  • Hydra Render Delegate: Patrick and Brecht made improvements to the build system, patch to make it easy to build against Houdini and with various fixes for Linux and macOS will be committed soon. Patrick still plans to look into issues regarding flaky viewports and scene scale. Many other improvements are also still possible, for example regarding device selection or materials integration, help is welcome.
  • AMD GPUs on Linux: Brian mentions the upcoming closed source 22.10 drivers have the fixes AMD has been testing blender with internally and should work, to be released next week. For some reason the open source ROCM 5.1 drivers did not have this fix, they’re working to get the people who maintain this to merge it asap.
  • AMD Vega GPUs on Windows: this unfortunately does not appear to be working and will be disabled again until issues are fixed in HIP.
  • Intel GPUs with OneAPI: Stefan mentions this will be targeted for Blender 3.3, as 3.2 would be too early. The main issue right now is regarding GPU compatible licensing of libraries we’d need to bundle with Blender, that come as part of the toolkit. Solution may be to either improve the open source version of the toolkit to work for Cycles, or change the licensing of the closed source one.
  • MNEE: Olivier contributed a patch to make this work on surfaces without UV maps, and various other fixes. Brecht mentioned ideas to separate MNEE into its own kernel, to solve issues with Metal and longer compile times, though it may be too early since we don’t yet know how this will integrate with path guiding. A quicker more limited solution for now may be to compile specialized shade surface kernels for AO, MNEE and AO + MNEE.
  • Volume motion blur: Kévin contributed a patch for using the velocity fields in volumes for motion blur, using advection. This is based on work by Tangent. Brecht will review.
  • Light groups: the feature was merged, and Lukas is working on further improvements especially regarding the UI in Blender.
  • Color management: Brecht made some improvements for the ACES configuration to work better, more is still planned, particularly the Blackbody node and compatibility with existing .blend files.
  • Curves: development is underway on a new curve object in Blender, and this will also need to be rendered in Cycles & Eevee. This will likely be planned for Blender 3.3. In Cycles, native rendering of Bézier and polylines seems possible, as these are already supported in OptiX and Embree, though work will be needed to get it working on all devices. NURBS curves are unlikely to be supported natively, and would need tessellation.

Practical Info

This is a weekly video chat meeting for planning and discussion of Blender rendering development. Any contributor (developer, UI/UX designer, writer, …) working on rendering in Blender is welcome to join and add proposed items to the agenda.

For users and other interested parties, we ask to read the meeting notes instead so that the meeting can remain focused.