Animation constraints are used to help automate the animation process. They can be used to control an object’s position, rotation, or scale through a binding relationship with another object.
A constraint requires one object and at least one target object. The target imposes specific limits on the constrained object.
For example, if you want to quickly animate an airplane flying a predefined path, you could use a path constraint to restrict the airplane’s motion to a spline path.
The constraint’s binding relationship with its targets can be animated on or off over a period of time.
Common uses for constraints:
There are seven types of constraints:
Attachment constraint attaches an object’s position to a face on another object
Surface constraint restricts an object’s position along the surface of another object
Path constraint restricts an object’s movement along a path
Position constraint causes the constrained object to follow the position of another object
Link constraint links the constrained object from one object to another
Look-At constraint constrains an object’s orientation so that it’s always looking at another object
Orientation constraint causes the rotation of the constrained object to follow the rotation of another object