Whe would you have different values particle separation vs voxel sizes

[anicg]

I was led to believe that the particle separation and the voxel size are meant to be the same value to avoid wasting resources.

In the attached file, the default preset that SideFx made for "Pyro Configure Billowy Smoke" (from the tab menu) has 3 different values:

1. Particle separation in pyrosource 0.05
2. Voxel size in volumerasterizeattributes 0.075
3. Voxel size Pyro solver 0.1

When would you have different values? are we gaining anything with earlier values of 0.05 and 0.075 when we're solving at a lower resolution of 0.1?

particle separation voxel size.hiplc

[ryew]

I was under the impression the higher resolution settings would be wasted at a lower-res simulation (and they do increase the per-frame sourcing time), but seeing how the sim changes when setting either or both the pyrosource and rasterize settings to 0.1 does show them having an impact, so it does appear to matter. 

I would have thought the higher resolution values in sourcing would simply be averaged or maxed when solved at 0.1 voxel resolution, but it doesn't seem like that is quite what is happening.  Diving down into those nodes might better explain what their doing under the hood, but in the meantime that's a good catch, and an interesting observation to experiment with.

Edited May 9, 2022 by ryew