Interaction of Smoke and geometry objects

I made a large box emitter and let some Marbles ran over it.

But how could I have some interaction with the smoke and marbles?
You know if marble is rolling over the smoke emitter, there should be an empty trail behind the marble for a few seconds - until the smoke start to rise again… This is what I am after now.

These are my settings now:

I know I had this kind of effect with many small candle flames = preset fire sphere emitters.

Hi @pekka.varis! I’ve pointed the dev team to your post.

Here is some documentation that may help: Fluid Dynamics — Omniverse Extensions documentation

See the Collision section in the documentation Wendy linked. Collision support is limited today. It requires recycling of emitters with special configuration. For a bunch of instances of spheres like this, should be feasible though using sphere emitters. My recollection was this was done for the original Marbles demo.