I'm currently playing around with the collision hull of moving entities, and I'd like to use a model to make the shape and size of it. I don't know how to do this, or even if it's possible with this engine. If not, how do I choose a very specific box size for the collision hull?

Thanks in advance.

Edit: Through more searching, I figured out how to set a custom bounding box, but it would still be nice to know how to make a model to be used as a bounding box.