Ok. What you are trying to do won't easily be accomplished. Lots of tweaking and it could be done with particles, but particles have no interaction with other objects, besides the ground plane. The physics properties you are looking at are to do with the particle emitter it will bounce off other objects etc. but not the particles. I believe CS4 is going to address animation issues like this, thats what they've said on the list anyway. You could simulate an effect like this with physics and numerous objects. Brian