* Bullet's convex hull implementation is significantly more robust
than the one I implemented, as well as being faster.
* This fixes bug [#32864] "Convex Hull fails in some cases."
projects.blender.org/tracker/?func=detail&aid=32864&group_id=9&atid=498
That bug, and others like it, relate to the poor handling of
co-planar surfaces in the input. Pretty much any model that is
simple-subdivided a few times gave very bad results before, Bullet's
implementation handles this much better.
* In order to ensure a smooth transition, the Bullet output is
translated into the existing HullTriangle hash structure. This makes
it easy to ensure that the existing slot output stays the same; the
interactions between the slots are somewhat complicated, detangling
is a TODO.
* Reviewed by Brecht:
https://codereview.appspot.com/6741063