NxActor *  actor [2] 
  The two actors connected by the joint. 
 
NxVec3  localNormal [2] 
  X axis of joint space, in actor[i]'s space, orthogonal to localAxis[i]. 
 
NxVec3  localAxis [2] 
  Z axis of joint space, in actor[i]'s space. This is the primary axis of the joint. 
 
NxVec3  localAnchor [2] 
  Attachment point of joint in actor[i]'s space.