Attendees
- Brecht Van Lommel (Blender)
- Sergey Sharybin (Blender)
- Weizhen Huang (Blender)
- Lukas Stockner (Blender)
- Nikita Sirgienko (Intel)
- Patrick Mours (NVIDIA)
Notes
For 4.2
- Decided to accept the performance impact on AMD/Intel Metal
- The slowdown only happens on specific hardware, which developers have no access to.
- High prio reports:
- Cycles HIP-RT Memory leak #120702
- Seems to be bug in the library
- Fixed in the open source version, which 4.3 is switching to
- For 4.2 wait for the possible NIP-RT update
- Blender crashing when using metal renderer #122022
- Michael Jones was looking into it
- OpenImageDenoise CUTLASS error after rendering image #122584
- All the crucial parts are fixed for 4.2
- Illegal address error with OptiX OSL with specific materials #122779
- Possibly a driver bug, Patrick is looking into it
- Possibility is to accept it for 4.2 initial release, and either look into work-around later, or have a fix done from the driver side.
- Cycles HIP-RT Memory leak #120702
- Release notes seems to be good
For 4.3
- White point patch
- All the current feedback has been addressed, needs the final review
- Known limitation: no feedback when picking something that is not close to blackbody radiation
- Compression of pre-compiled libraries has landed #123557
- Diffuse roughness control for principled BSDF
- Need review from the Cycles side. Weizhen and Sergey will take care of that
- EEVEE side is done
- Weizhen is looking into bug reports, solving long-standing issues
- Brecht is updating Cycles standalone
- The script cycles_commits_sync.py is in the blender.git repository
- Takes a bit longer than usually, because of the Git-LFS changes
- Brecht cleaned up the project workboard, so there is now a column for the near-term next tasks to tackle
- Alaska is working on patch to remove Intel/AMD Metal codepaths. Sergey reviews, hopefully land soon
- Volume phase functions #123532
- NVidia paper looks very interesting
- Lukas would love to have a review
- Some preliminary feedback:
- Add links to papers
- Better explanation of what the new phase functions are on artistic level
- Are the parameters good and friendly for artists?
- How do you mix different lobes?
- Replace current one with the new one?
Future:
- Split principled BSDF node
- Helps EEVEE parameters (the GLSL parameters limit)
- Helps OSL to discard unused closures
- Probably better be done on the render engine side (as opposite to the Blender side) since layering might be done differently by different engines
- How to handle volumes
- Best acceleration structure
- Combine them or sample separately
- Look into what the state of the art is
- The meeting mainly raised this topic, needs further investigation
- Multi-part EXR files #123727
- Helps speeding up load of EXR in external software
- Eventually Blender will also only load requires passes, so will help there as well
- Implement as an option, or even by default
- Nikita raised a discussion of solving technical debt
- Would be good to tackle it shorter term, and not for Blender 8.0
- Testing frameworks are available already, but some aspects of Blender/Cycles might be hard to unit test
- Need to look into it, and make code easy to unit test
- Sergey is very interested in this, but has limited time. Nikita might have time to look into it for the denoise device selection
- In the longer term we should strive towards accepting new features with tests included
- Another technical debt topic was splitting up CMakeLists.txt. Could help some on-going development
- There is old-standing patch to rework CUDA kernel build to use separable compilation #119746
- Is still something to look into, but needs development time and priority
- Doing kernel compression for AoT Intel kernels is being investigated
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: July 9 2024, 5 to 6 PM Amsterdam Time (Your local time: 2024-07-09T15:00:00Z)