2021-01-12 Blender Rendering Meeting


  • Brecht Van Lommel (Blender)
  • Kévin Dietrich (Blender)
  • Jeroen Bakker (Blender)
  • Stefan Werner (Tangent)
  • Edoardo (Tangent)
  • Sergen Eren (Tanget)
  • Thomas Arcila (AMD)
  • Brian Savery (AMD)
  • Patrick Mours (NVIDIA)
  • Max Dmitrichenko (Intel)



  • Optix SDK upgraded to 7.1 to increase max number of object instances.
  • High res renders performance regression: Brecht wasn’t sure if this was done for 2.92, Jeroen explained it was already fixed. (commit)
  • SSS Dwivedi sampling by Lukas: Brecht will review
  • Point cloud: Brecht asks for help with OptiX implementation, Patrick will check
  • OptiX curve primitive: recent OptiX changes are expected to make the shape match the Cycles native primitive more closely, if so then this can then be enabled by Patrick soon
  • Brecht proposes to disable branched path tracing for the GPU since it has poor performance and timeouts, the algorithm was never suitable for the GPU. Code review will be submitted, needs a bit more analysis to check if this is ok. Would significantly simply OpenCL split kernel and in general make it easier to do refactoring for GPU rendering optimizations.
  • Baking workflow: initial design doc created (task)


  • AMD Polaris normals bug
    • Jeroen implemented a workaround in 2.92. Expected to be backported to 2.83 LTS and 2.91
    • Thomas reports AMD is in the process of narrowing down where in the driver stack this bug is.

Render Pipeline

  • Cryptomatte metadata is now preserved with the compositor file output node (commit)

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: January 17, 2021