Hi There

I'm relatively new to Houdini and wondered what the best course of action would be to create a particle network that not only collided with other geometry but one that also collided with itself, i.e. particle self-collisions. Ideally I would like to be able to transfer velocity between collisions to enable correct reactions and just to throw one more requirement in, I'd also like to use instanced geometry for each particle.

The idea is to create a animation of various sized marbles bouncing/rolling down some stairs. There may be quite a few marbles, say 100+ so RBD was something I was thinking of staying well clear of!

thanks in advance for any help

I think your best bet here is to use a RBD simulation. Particles can collide with each other, but it only takes into account the location of a particle. I think you can make the collision distance bigger to simulate bigger particles, but you can't vary it for each particle. Also, Houdini seems to do well with RBD simulations, even with 100 rigid bodies.