10
« on: 2018-05-13, 21:57:59 »
Some tips on making density mapped bit faster:
1, Lower GI/AA - this seems to help a lot. You can go as low as 2, just not go to 1. There's some bug which causes weirdness when GI/AA is at 1.
2, Enable "single bounce only" whenever possible. This is very important. Multibounce just completely kills performance.
3, If you use "single bounce only", then increase Light Samples Multiplier to 4 or even 6. Since "single bounce only" causes volume to scatter only direct light, not indirect, then LSM is now the main driver of speed/quality balance for noise levels in volumes.
4, Step size actually needs to be increased to speed things up, not decreased. Larger values will make rendering faster, lower values will make rendering slower. Good rule of thumb is to start with really large value. For example if you have 10 meter wide cloud, then start with step size of 1 meter. If you see some raymarching artifacts (sort of sharp slices throughout the volume), start slowly decreasing step size until they are not visible anymore.