Hi GilG,
Collisions aren't working because in your Particle Physics operator you've filtered collisions to only process particles in sim group 1, but you haven't assigned sim group 1 to any particles in the flow...so there is nothing to collide
Collisions aren't working because in your Particle Physics operator you've filtered collisions to only process particles in sim group 1, but you haven't assigned sim group 1 to any particles in the flow...so there is nothing to collide