at the moment i am trying to create rubble/ debris to look like a cave in or blasting in an underground mine.

i am currently attempting to use particles with a gravity field and rigid bodies, the rigid bodies act as a funnel to channel the particles towards the area i require.

the problem i am having is that the particles seem to have no collision geometry in relation to themselves, that is they collide with the rigid bodies but are allowed to pass through other particles in the particleshape and spread across the surface of the rigid body instead of piling up on top of each other.

How can i correct this?

Am i heading i the right direction or is there a simpler way to create this effect?

help would be greatly appreciated,