This week I tried porting over to Unity 5.  It went pretty smoothly to start with, a few shader and code tweaks were required to get everything running properly, but nothing too bad.  However once I got things going I found some pretty fundamental physics bugs that totally break my game:-

• Once frozen, rigidbody rotations can’t be unfrozen (positions are fine).

• Joint motors, limits and velocity drives seem to be non-functional (at least when setting them from code).

• The OnCollisionExit callback never seems to be called.

It’s a pity really, as I can already tell the physics performance is significantly improved (which I sorely need!), but for now I’ll have to stick with Unity 4.6.  Hopefully Unity will resolve these issues fairly soon.

In the meantime I’ll have to re-jig my task plan a bit, but it shouldn’t hold things up too badly.