Today we scale live dynamic objects and make the scaling affect the running sim. You’ll gain some insights into how the Bullet solver inside of Houdini works and how it operates more efficiently using packed primitives. Manuel goes over the ins and outs of modifying a Bullet sim dynamically.
The problem with modifying the intrinsic transform of dynamic Bullet objects is, that Bullet does not update it’s collision geometry accordingly. Using a trick we make it think that it deals with new objects and thus reconstructs its collision hulls.