whats the advantage of a smoke-velocity based particlesim vs. a normal vel based, i.e. vel in vdb? is it just the look an feel? A fundamental explanation with the pros and cons and the relevant areas of application would be fantastic.

Thanks in advance, happy eastern, good luck and keep healthy

There is none. It's about the look. Using vel from a smoke sim means you'll be getting velocities that
respect fluid dynamics, so when using them in your popsim, the points will move much more realistically in terms of vel
existing, and moving correctly in terms of physics.
You making your own vel field, that totally works also, but unless it's running through a fluid sim, it won't respect
non-divergence. Both methods are used, it only has to "look right," but having said that, it's usually much easier to use
a velocity field from a fluid sim to advect, as it's motion is correct out of the box, Vs you fighting to make your own fields
to mimic this.
I tend to use either or a combination of both in the pop sim. It really just comes down to the physically correct nature of the
field coming out of a smoke sim.


L

tinyhawkus
Using vel from a smoke sim means you'll be getting velocities that
respect fluid dynamics, so when using them in your popsim, the points will move much more realistically in terms of vel
existing, and moving correctly in terms of physics.
You making your own vel field, that totally works also, but unless it's running through a fluid sim, it won't respect
non-divergence.
L

I'd add that the heavier the dust particles the less they observe non-divergence. That's why sometimes you see dust sims that look overly gassy.

Ok, thanks to both. That’s the same I thought. Smoother motion in case of fluids and the divergence thing. So I use normally both, depending on the goal. It would be interesting to see how you are using both together, „an out of the box (smoke sim)“ paired with a custom velocity setup. Maybe someone could post a hip for that? Would be great.

Some links for further reading are also heavily welcome.
Keep going and keep healthy.