A planar joint — the child translates within a plane and rotates about its
normal (3 DOF). plane.direction is the normal; plane.origin the rotation
anchor. DOF order: [u-translation, v-translation, rotation], where the
translations are applied in the plane frame (independent of the rotation).
A planar joint — the child translates within a plane and rotates about its normal (3 DOF).
plane.directionis the normal;plane.originthe rotation anchor. DOF order:[u-translation, v-translation, rotation], where the translations are applied in the plane frame (independent of the rotation).