The first problem is to define center. The only way that comes to mind is just change the Vertex information in the TriMesh so that 0,0,0 is the "center" that you want (IE move them all up or down some) and just rotate like normal.
I would love it to be anywhere. I.e. defining a pivot point. So It would be nice if I say defined the pivot point at around -100, -100, -100 and it would rotate around that point… I guess its a similar thing to what your doing.
Yeah … You could probably use the getcenter method, get the difference between (0,0,0) and then translate the whole model within it’s local coordinate space to that position. But it would be nice if there was a setAxisOfRotation method or something hehe For now since I’m just doing tech demos I’ll change the coords by hand since theres only 5 vertices to do. (its a tri mesh)