Creating a physics asset - workflow

I’ve been tearing my hair out trying to set up a physics asset for our custom character and I thought it might be nice to start a thread with “lessons learned” in the hope that others can add insight and help future developers.

To remember:

  • Make sure each joint between bones has a constraint otherwise any children will detach from the body
  • Constraints often need to be moved manually to the joint, which can be visualized using Character->Bones->All Hierarchy
  • To rotate a constraint (such that the joint’s range of motion changes), hold alt while adjusting
  • Physics bodies (i.e. the collision capsules for each bone) themselves can overlap but make sure those that overlap do not collide with each other. A good tip is to enable collision from all and manually switch collision off between any overlapping bodies.
  • If you mess up a constraint and need to reset, the best way seems to be to delete and recreate.


  • The cones that appear to represent range of motion for each constraint have no basis in reality. The cones do not represent the actual angles that define ranges of motion. I have no idea how this has been the case for years but it makes setting up constraints an incredibly tedious trial and error process.