How do I create a particle system from an imported stl model and use that to fill the shell of another model? As you can see below, I want to fill the model to the right. There are two issues I am having. 1) The body is currently emitting the mini figurines rather that the internally contained collisions I was expecting. 2) A displaced modifier was applied to prevent the particles from moving beyond the skin, but if I could just set the collision boundary to the skin itself, that would be best. I read that applied modifiers are permanent, so I may need to redo this particle system on the original stl. Thank you!
(11/9/20) Tried Vertex paint mode and selecting the body under the Vertex Group --> Desnity, but it still had the same effect. I think the problem also is that internal face or area is not the source of the emitter. However, I found a tutorial here that shows how to fill a container by funneling the smaller objects via implemented physics engine. Will see if that works!