2024-07-09 Render & Cycles Meeting


  • Sergey Sharybin (Blender)
  • Weizhen Huang (Blender)
  • Lukas Stockner (Blender)
  • Nikita Sirgienko (Intel)


For 4.2

  • Crashes when using Metal was fixed by Michael Jones
  • No updates on HIP-RT memory leak and OptiX OSL
    • The previous idea of accepting known issues for the original 4.2 with a bug fix via driver or corrective release is open.

For 4.3

  • Wehzhen and Alaska are looking into expanding test coverage
  • Light linking and volume fix was re-iterated
    • Fixes immediate studio requirements.
    • Does not work correctly for nested volumes (which is similar in 4.1).
    • More complete fix is in discussion.
  • There is a report about self-intersecting volume objects
    • Cycles does early exit from the volume
    • Should be possible to consider such configuration as a “union” operation over the mesh parts
  • Weizhen is looking into implementing stochastic noise paper
    • CPU might not benefit from it that much, as the code is vectorized, so current focus is GPU
    • There is measurable speedup, but the image looks more noisy
    • Possibly required a better RNG state. The team will check on how to implement it offline.
    • Bump mapping is wrong with stochastic noise


  • Intel is looking into implementing kernel compression as a DPC++ feature.
  • The meeting went into a quick summary of papers from EGSR. There are some interesting ones, but maybe ot the highest priority.

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.


Which paper is that?

Fast Procedural Noise By Monte Carlo Sampling
Fajardo, Marcos and Pharr, Matt