goldleaf
This is great cybermax!
BTW, it would be really helpful if there were more primitives to have access to, like the Bullet DOP provides (capsules, cones, etc…). The btCompound and btMultisphere shapes are faster than simply constraining lots of objects together, and having the btStaticPlaneShape for a groundplane option in the properties sop node would also help speed things up when colliding lots of objects to the ground. Another nice use for btMultiSphereShape, is that you can get non-uniform sphere primitives. I'm just adding this to the Bullet DOP now, so once its up, the code will be open for you to refer to.
btCompound shape you can create easily with sop_multijoints or sop_constraints, there is fracture option. In example file is example, but for child shape It use voronoi piece, but you can changescene to sphere(btMultiSphere), which fill object. maybe I create example.
goldleafAll works with SOP_Properties is in source code. libBullet.a is only for SOP_Solver.
I looked at trying to implement these myself, but as far as I can tell, those are all done in your libBullet.a, right? Only the node interface is done in SOP_Properties, but the actual primitives need to be setup by you, if I understand it correctly.