The user can create a force entity as follows.
• Joint
• Joint: Selects a revolute joint or a cylindrical joint.
• Point, Direction
• Point: Selects a point on two bodies to define the location of rotational spring force.
• Direction: Defines the direction of z-axis of rotational spring force.
• Body, Body, Point, Direction
• Body: Selects a base body of rotational spring force.
• Body: Selects an action body of rotational spring force.
• Point: Selects a point on two bodies to define the location of rotational spring force.
• Direction: Defines the direction of z-axis of rotational spring force.