ee2fe7fa6c
The same random number was used for sampling color channel at each step, which leads to bias. Fixed by rescaling the random number. Another possibility would be to scramble `rng_offset` and use a new random number each time, similar as in subsurface scattering, but rescaling random number should be faster than computing a new one, and is favorable here since the precision here is not very important Pull Request: https://projects.blender.org/blender/blender/pulls/127454