Hi,

I'm currently working on my first „real“ Houdini project and trying to create vortex like swirls behind a fast moving object which flies through a foggy room. I also want to render the swirls separately, for more flexibility in comp but this seems to get tricky. I already have a particle system which gives me the desired look but I'm not sure if my current setup (see attached file) is the best way of archiving this effect. Currently I'm multiplying the density with the vel. field in the pyro shader, but there's probably a more efficient way of doing this. Maybe i cloud try to source smoke directly from the particles or shade the particle like the fog in the background without any use of the fluid solvers ?
What's the best approach for this kind of effect ? Am I on the right way ?

thanks in advance