vellum grain lowres to highres

[mimimou]

Hi everyone,

Im trying to find a way to get the same sim result when I use a low and high number of grains. I have a deformed cube (my foam shape) that I want to break into 2 parts during the sim, and want to have tiny grains on the surface for the bubbles.

When I convert my geo into vellum grain with a particle size of 0.05, and add a vellum glue constraint with a break threshold, I'm happy with the sim result, but once I'm lowering the particle size to 0.01 to get much more tiny grains, the simulation behaves completely differently, which is normal.

I tried to use 2 sources, one lower vellum grain for the sim, and another one for the tiny grains only on the surface, and use a point deform node to constrain the tiny grains to the lower grains, but it's not working, especially when the grains split in 2 separated parts.

And since the simulated foam mesh is a VDB converted to polygons, the topology change and there is no way to use a scatter node on the surface.

So is there a way to get the same simulation with lower and higher number of grains? or any another idea I haven't think about to achieve this?

Thanks