I need to chk for scene because i don't have permission to share it, but let me try to explain.
Mesh part
I just split particles using speed and vorticity, and low speed/vort areas i used vdb from particle fluid with some smooth mask, same as default particle fluid mesh do
and on high speed/vort values i add high res settings on vdb from particles fluid and then just combined 2 vdb volumes and convert to poly, thats all
Rendering part
- its just fluid mesh with displacment on top, using speed and vorticity to add bit of color, and there is simple bubbles and foam sim render as points under surface.
- no this is not like whale sim, on whale i did convert surface filed to mesh and then add displacment, but because i wanted to get all details from sim, i did fluid mesh on this one.