Hello,

Could anyone explain exactly how pyro collisions work? In some cases, it doesn't seem like collisions with the smoke solver are “real” when using moving colliders. It seems like 2 things happen when using an animated static object:

1. Takes the velocity from the collider and advects the smoke with it
2. Delete any density that goes inside collision object (can be disabled)

Look at my gif. If I disable velocity from the collision nothings happens. The density just gets deleted. In the example I turned off correct collisions for better visualization. If the collisions were “real”, I would expect the density to move when the collider moves, then stop once the collider stops since no velocity from the collider is being applied.

Any ideas?

smoke collision [gfycat.com]