Sets whether the HingeConstraint will limit the range of rotation. If enabled, the constraint will only allow the HingeConstraint/CurrentAngle to be between HingeConstraint/LowerAngle and HingeConstraint/UpperAngle. If the Attachment reach the end of the limited range of rotation then they will stop rotating. If HingeConstraint/Restitution is greater than 0 then the attachments will bounce when they hit the ends of the limited range.

For example, here is the result if LowerAngle is set to -90 and UpperAngle is set to 45. Note that the x-axis of the Attachment in PartA is pointed away from the camera: