2025-01-07 Render & Cycles Meeting

[sergey]

Attendees

• Brecht Van Lommel (Blender)
• Sergey Sharybin (Blender)
• Nikita Sirgienko (Intel)
• Sahar A. Kashi (AMD)
• Xavier Hallade

Notes

• For Blender 4.4
  • HIP update to 6.2 is on-track. Question about what version to target for for gfx12. There is a bit of version difference between Linux/Windows
    • Linux 6.3
    • Windows 6.2
    • Will sync-up with Sahar in the task tracking the update: #131976 - Cycles: Update ROCm/HIP to 6.2.4 for Blender 4.4 - blender - Blender Projects
  • Embree update
    • New Embree fixes threading-related bug leading to crash
    • Wait for the update from Nikita
  • OIDN update
    • Need to update the libraries tracking: #128577 - Library changes for Blender 4.4 - blender - Blender Projects
  • DPC++ will need to be updated. Details coming
    • Pre-compiled kernel compression is coming!
  • HIP-RT will be updated as well
    • Point cloud fixes
    • Bytecodes do not need to be compiled
• Other
  • Brecht cleanup Cycles for clangd: Using clangd
  • Make it somehow more clear for people who does benchmarks that LTS is not the best to depict performance on the new released hardware.
    • Add a warning in the benchmark launcher?
    • Add a warning in the Blender LTS itself when a device from the future is detected?

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.

• Google Meet
• Google Calendar Event
• Next Meeting: January 21 2025, 3 to 4 PM Amsterdam Time (Your local time: 2025-01-21T14:00:00Z)

[JohnDow]

Since you updated/bumped Optix some time ago, its denoiser stopped working on some (all?) Nvidia GPUs in CUDA ‘mode’. Is that an expected behavior or a bug?

[ThomasDinges]

Please report bugs via Help → Report a bug from within Blender or manually via the website.

[Alaska]

See this section of the release notes for Blender 4.2: Cycles - Blender Developer Documentation

• CPU renders can now also use GPU accelerated denoising. (PR#118841)
  The denoiser uses GPU device configured in the User Preferences. The side-effect of this is that OptiX denoiser requires having OptiX compute device configured in the preferences.