Cycles Development Updates

Someone has already made some lens simulations with the ray portal BSDF, and the results seem quite good!

4 Likes

Yes, I know what Heinzelnisse has been doing…
I’ve been doing similar experiments with the RayPortal myself (thought I’ve been using 2.5D variations of the ray transfer matrix, and he’s using full refraction math).

But even so, as I mentioned above, the problem is that using the RayPortal doesn’t converge fast enough to a noise free solution (too many samples where aren’t needed, and too little sampling where it does)… Having Cycles to be able to converge faster is needed, and Lukas’ PR might improve that a lot.

How would things like Path Guiding and Light Trees work when portals are involved, because last I checked it does not appear to be something that is commonly utilized in patch tracing?

If these things have full compatibility with portals already, then that would be a surprise.

The RayPortal doesn’t do any fancy stuff… it is actually very simple and it just moves the ray to another location and direction.
I don’t know how exactly Path Guiding works, but I think it deals with the RayPortal the same way as any other closure. (after all, the Transparent bsdf is the only closure that doesn’t change the ray vectors.)

But in relation to custom lenses, the problem isn’t really the PathGuiding… It’s just that rays from the film sensor (camera), have too much variation, in a similar manner as DOF.

3 Likes

OpenPGL on GPU is advancing. Sebastian is working on making it so the render info is gathered from the render kernel

At the Blender Conference there was a demo of OpenPGL working on GPU with pre-exiting render info.

This is good to see.

8 Likes

Attendees

  • Lukas Stockner (Blender)
  • Nikita Sirgienko (Intel)
  • Patrick Mours (NVIDIA)
  • Sahar A. Kashi (AMD)
  • Sebastian Herholz (Intel)
  • Sergey Sharybin (Blender)
  • Thomas Dinges (Blender)
  • Weizhen Huang (Blender)

Notes

  • For 4.3
    • CPU / GPU difference
      • The fix has been commited to main. Avaiting backport.
      • The report can be closed?
    • Handling SDK/ROCm 6+ lack of backward compatibility with pre ROCm 6 #130153
      • Sergey will check on avoiding cache variable and use find_package(HIP) in extern/hipew
      • Requires re-compilation of HIP-RT on Linux to prefer ROCm 6.
  • Other
    • Lukas keeps working on the OSL camera. Getting close to the state where public testing will be needed. Feedback thread coming up!
    • The meeting went into discussion in the mix of signed and unsigned for arithmetic. The solution seem to be:
      • Use signed arithmetic
      • Add assert() in cases where something is not expected to be negative
      • Convert macros to inline functions if that helps compiler
    • OpenPGL on GPU is advancing. Sebastian is working on making it so the render info is gathered from the render kernel
      • At the Blender Conference there was a demo of OpenPGL working on GPU with pre-exiting render info.
    • The module will look into creating a task for the Quality project, to make it more visible and clear
    • Weizhen works on octrees
      • Switched to per-volume octree to make updates more instant
      • Need to solve overlapping octree case
      • perlin noise: hash and fmod are slow

NOTE: In order to solve scheduling conflict with some of the active contributors the meeting is moved 2 hours earlier, at 15:00 CET.

7 Likes

:eyes:

19 Likes

Volume rendering update :heart::fire:
Already looking promising

12 Likes

2025-01-07 Render & Cycles Meeting

Attendees

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

Notes

  • For Blender 4.4
  • 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?
4 Likes

Anything holding up the OpenPGL upgrade, otherwise it is looking like a very light release for Cycles coming up with the vast majority of changes being invisible to the user?

3 Likes

for people stile using 2.93 LTS OR old Cycles

Blender is flying on this poor little GFX8 (Polaris 20, 8 GB).:star_struck:

Great to known that even older Blender (most likely LTS 2.93) is working with rusticl on old GCN4 aka GFX8 hardware. :+1:
ROCm is by the way not an option here because it only supports RDNA based GPUs (and with some tweaks maybe certain GCN5 / GFX9 models.)

Haven’t been following Cycles lately. What are the big projects being developed ?
Any news on Open PGL GPU, ReSTIR, MipMaps, Spectral, … ?

Here is an updated on the cycles development:

:man_shrugging: Library updates, developer tooling and communications for benchmarks, is that all ? Aren’t Lukas and Weizhen working on Cycles ?
Feels like the last large batch of features was 4.0 more than a year ago, with AgX, Path Guiding, Principled BSDF and Light Linking.
Don’t want to sound disgruntled, just curious about what happened this year.

If you are truly curious, you are in luck, you can see every single line of code touched by any of your favorite developers right here:

Also, if you don’t want to sound disgruntled, avoid using the phrase ‘is that all?’ and shrugging emojis.

6 Likes

Ah my bad, got it !
OSL Cameras, Volume octree optimizations, Open PGL on GPU.
Hope we get news soon about mipmaps, ReSTIR and Spectral !

What’s that now? What happened to OpenPGL and GPUs? Is it working on GPUs now?

Wishful thinking.

We might hear about it sooner than later ! Doesn’t seem that wishful.

Might even come with a cherry on the top :cherries:

2 Likes

Sounds like wishful thinking. I bet it’s still going to be a few years.

1 Like