Model falling down issue

[Thor]

I'm not sure what you mean by particles self-colliding. Self-collsions would only happen in something like cloth, not a static mesh.

As for having the floating chunks fall...typically you'd need to setup a bind network to determine chunk connectivity and then use a Property Test to see when a chunk has no connectivity anymore and then send it out to the gravity event in that case. There's an example file showing how to do....if I remember correctly, it's tyFlow_bindSearch_001.max in the official example files.

Thanks a lot. I'll take a look at binds and see how it goes!