After the tracking is complete, you can set a layer to follow the tracking using the Animation, Track Layer to Video menu. This opens the Motion Tracking dialog box, shown in Figure 28.3. Using this dialog box, you can select the tracked movie to use and select two tracking points.
The primary tracking point sets the motion of the layer to follow, and the secondary tracking point can be set to control either the angle or the scale of the layer. If no secondary point is used, then you can select None as the secondary point.
The Animation, Track Layer to Video ...