Tim van Helsdingen Shows a Method for Dealing with Concave Collisions in Houdini’s Bullet Solver.
While working with Bullet in Houdini, you may have found that applying simulation to objects that have concave surfaces is problematic. Bullet and concave surfaces together are super slow. That isn’t to say that there are no ways around the problem. FX Artist Tim van Helsdingen shares some techniques for working with concave surfaces in bullet simulations.
If you are following along, Tim offers the scene file for download here. Tim also notes of two additional tidbits that are not in the tutorial. “here’s a slight error in the video where I use the primitive sop, it needs to be assembled before the primitive and later unpacked again, and then the copy. I have updated it in the hip file,” Tim says. Also, “Apparently there is now a ‘Convex Decomposition’ node that does the same as described here but in a single blackboxed asset. But guess it’s still useful knowledge to have :)”.