After you create an aim constraint, you can add more target objects for additional control over the constrained object’s orientation. Adding more target objects is similar to creating aim constraints.
To add target objects
The Aim Constraint Options window appears.
After you create an aim constraint, you can remove any of the target objects so that the objects no longer constrain the constrained object. Removing target objects is similar to adding target objects.
To remove target objects
Note that when you remove a target object, you also remove any animation curves attached to the constraint object for that target object.
You can also remove specific axes from a constraint. For this procedure, see Modify Constraint Axes.