I was wondering simply what the limitations are of creating shapes like this in a 3D modeling program. In other words, how complex can they be?. Can they be a single plus shape (+) or will that need to be made out of two boxes (or more, if they can't overlap)? How about a torus knot?
Maybe it's easier to ask if the collisionhull/collisionmesh shapes must be convex as well, like the convex shape examples in the tutorial.
(I am aware that they don't work with animated models though.)