Apple Motion 5.1.1 - Manual (Page 987)

Chapter 22 Motion tracking 987
As you Command-drag the track point, an inset displays a magnified view of the frame specified
in the Look Ahead Frames parameter.
5 When the look-ahead tracker is positioned on the reference pattern, release the mouse button.
When you click the Analyze button, the new reference point is used as the tracking pattern.
Note: Look Ahead Frames can be used when tracking in reverse. When the Reverse checkbox is
selected in the tracking behavior’s parameters and you use the Look Ahead Frames parameter,
you are looking at previous frames rather than future frames. The Reverse checkbox is only
available for the Analyze Motion, Track (in the Parameter behaviors category), and Track Points (in
the Shape behaviors category) behaviors.
Manually coax a track using the Record button
For challenging tracks, you can manually insert track position keyframes to help guide the
tracker towards a reference pattern. For example, if you have footage with significant motion blur
or objects that partially obscure the tracking pattern, you can manually create tracker position
keyframes to help guide the tracker.
1 Apply a Motion Tracking behavior to the clip, then enable Record (press A).
2 In the Canvas, position the tracker at the reference point you want to track.
A track position keyframe is created in the behavior (visible in the Keyframe Editor).
3 Navigate to the next frame where you want to create a keyframe.
Note: You can press Shift-Right Arrow key to jump forward ten frames, or press Shift-Left Arrow
key to jump backward ten frames.
4 In the Canvas, position the tracker at the reference point you want to track.
5 Repeat steps 3 and 4 until you’ve completed the track.
6 In the Behaviors Inspector, click the disclosure triangle for the track you have manually adjusted,
then choose Use Existing Keyframes from the Fail Behavior pop-up menu.
7 Turn off the Record button (press A).
8 Go to the first frame of the clip, then click the Analyze button in the behavior HUD or Inspector.
Important: Even though keyframes are created, you must analyze the footage to obtain the
tracking data.
Manually coax a track without enabling Record
1 Apply a Motion Tracking behavior to the clip.
2 In the Canvas, position the tracker at the reference point you want to track.
3 Choose Object > Add Position Keyframe.
This command is available for the Analyze Motion, Match Move, Stabilize (with manual trackers),
Track Points (in the Shape behaviors category), and Track (in the Parameter behaviors category)
behaviors.
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