2022-2-1 Blender Rendering Meeting


  • Brecht Van Lommel (Blender)
  • Thomas Dinges (Blender)
  • Brian Savery (AMD)
  • Patrick Mours (NVIDIA)
  • Christophe Hery (Facebook)
  • Feng Xie (Facebook)
  • Olivier Maury (Facebook)



  • Ray offset: patch landed, Brecht still working on solving issues with duplicated objects generated by Blender particle system. To be solved either in the particle system, or in Cycles to handle objects/faces in exactly the same place.
  • AMD HIP: Linux support is being worked on, however the aimed driver release date is just right before the Blender 3.1 release, which would not leave enough time for testing and fixing issues. So plan is to enable that only in Blender 3.2 alpha, which should then be available with HIP support for testing around the time of the 3.1 release.
  • Metal: maOS 12.2 was released with fixes for some failing Cycles tests related to volumes, the remaining failures are in baking for which there is a workaround that we can commit. There is a known issue with macOS 12.3 beta which is being looked at.
  • CPU + GPU: Brian mentions a patch for improving performance for this case, not perfect scaling but certainly solving some cases where it is slower than only GPU now.
  • Multi-GPU: Feng prototyped a patch for better scaling, by distributing alternating slices of the render to different GPUs to ensure a more even distribution, and not do any rebalancing. This showed a 8x scaling on a 10 GPU setup. This approach works well when using the same GPU model, however with hybrid CPU + GPU or a slower and faster GPU, we’d still need rebalancing.
  • MNEE: Brecht did an initial review of the patch, Olivier will update it to address the comments. Also needs some updates for the ray offset changes. We discussed more general specular manifold sampling, and that making that practical for real scenes probably requires a combination with path guiding.

Materials & Textures

  • One of the Blender strategic targets for 2022 is texturing. There were design and planning discussions about that at the Blender Studio this week, we’ll soon share initial designs for wider community feedback.

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.

  • Agenda
  • Google Meet
  • Time: Tuesday 5 to 6 PM Amsterdam Time
  • Next Meeting: February 15, 2022

Hi all, what’s happened about the 15th February meeting?
Can’t seem to find info about it.



YES! “specular manifold sampling” and “path guiding” :grin:

Were there any meeting notes?

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Looks like we can only get together next time :sob: