Apple Motion 4 - Manual (Page 1254)

The tracker is added to the footage. By default, a single tracker appears at the center of
the footage.
Tracker
2 Play your background clip several times to determine a good track point, then go to the
frame where you want to start the track.
3 In the Canvas, drag the tracker to the reference point you want to use.
Note: For more information on using the onscreen tracker, see Adjusting the Onscreen
Trackers . For more information on selecting a good tracking reference point, see Strategies
for Better Tracking .
4 To add trackers, click the Add button in the Behaviors tab of the Inspector.
Each new tracker is added to the center of the footage.
5 Drag the additional trackers to the reference points you want to use.
6 To track a specific range of frames, adjust the start and end points of the tracking behavior
(the purple bar) in the Timeline or mini-Timeline.
Note: If you adjust the length of the tracking behavior, make sure to set your tracking
reference points within the range of the behavior. In other words, if you set the tracker
to a point on the first frame of a clip, then change the start point of the tracking behavior,
the tracker will not analyze the point.
7 Click the Analyze button in the HUD or Behaviors tab of the Inspector.
Analyze button
1254 Chapter 19 Motion Tracking