A Barrier constraint creates an infinite barrier plane beyond which the center of mass of the rigid body will not move. You can use a Barrier constraint to create objects that block other objects, for instance, a wall or floor.

You can save processing time by using this type of constraint in place of a collision effect. However, objects will deflect but not bounce off the plane. To constrain multiple objects, you must create a Barrier constraint for each object.

This constraint works only with a single active rigid body; it does not constrain a passive rigid body.

To create a Barrier constraint

1. Select the rigid body you want to constrain.
2. Select Soft/Rigid Bodies > Create Barrier Constraint > to display the options window.
3. For the Constraint Type, select Barrier.
4. Turn on Set Initial Position and enter X, Y, and Z values for the Initial Position of any position on the plane. The position is irrelevant because the Barrier is an infinite plane.

   If you don’t turn on Set Initial Position, the Barrier plane is created at the origin and connected to the center of mass of the selected rigid body. The barrier plane is oriented on the XZ plane.

5. If you want to set the initial orientation of the barrier plane, enter X, Y, and Z values (in degrees, by default) for Initial Orientation.

   By default, the Barrier constraint is oriented on the XZ plane.

   Tip

   After you create the constraint, you can use the Move and Rotate tools to change its position and orientation conveniently in the workspace.

6. Click Create in the Constraint Options window.

   An square icon appears in the workspace at the Barrier plane position.

   A perpendicular line sticking up from the Barrier plane icon indicates the normal direction of the plane surface. Only this side of the surface constrains the rigid body.

   To alter the constraint after creation, see Edit constraints.