okay so
@SpaceGrenadier and
@teortaxesTex the cheetah is STILL going, but I made it stop to publish intermediate results, which I would say were fairly middling.
the cheetah is honestly kind of a nightmare case imo because the previous demo is based on an assumption of mostly rigid physics and a cheetah is more like a rubber band creature of highly elastic tendons.
if I were to start this again, I would have it think more carefully about how to model (and if we even can model) a soft body with some rigid constraints inside of it rather than presuming that all skeletons are principally rigid.