Use the Link Dummy Mechanism to update dummy and seat motion.
        After changing the position of a dummy and seat, the seatbelt tool can
            automatically update the full seatbelt system.
        
                In the Entity Editor, activate the Link
                        Dummy Mechanism checkbox.
                If the Link Dummy Mechanism is not activated, you can still update on demand
                    by right-clicking on the appropriate seatbelt system and selecting
                        Update from the context menu.