Apple Motion 4 - Manual (Page 1299)

Adding Trackers to the Stabilization
If a stabilized clip has a particularly bumpy section that is not getting smoothed, you can
add trackers to noncontiguous sections of a clip.
Any stabilize data from the automatic motion analysis is overwritten by the portions of
the clip that are analyzed using the onscreen trackers.
To use a tracker for a portion of a stabilize operation
1 Once the Stabilize motion analysis is complete, play the clip to determine what section
you want to track.
Important: Always analyze the entire clip before adding any trackers. The Stabilize behavior
needs “’meaningful” data—a large range of frames—to yield the best results.
2 Set an Out point for the tracker analysis: Position the playhead at the frame you want to
stop the analysis, then choose Mark > Mark Play Range Out (or press Command-Option-O).
3 Position the playhead at the frame where you want to start the track, then click the Add
button in the Inspector.
4 Position the newly added tracker on the reference pattern you want to track in the Canvas,
then click the Analyze button in the HUD or Inspector.
The specified play range is tracked, creating track points in the Canvas and tracking
keyframes in the Keyframe Editor.
Note: When using this strategy to track multiple noncontiguous sections of the clip, use
the same tracker whenever possible to simplify the track and to avoid clutter in the
Keyframe Editor.
This strategy is not recommended for small portions of the clip, such as using the default
stabilization for 25 frames, a tracker analysis for 10 frames, the default stabilization for
10 frames, and so on.
Changing the Smoothing Parameters
If you’re trying to smooth the motion in a clip, you should first try adjusting the smoothing
parameters. These parameters include Translation Smooth, Rotation Smooth, and Scale
Smooth. This can be accomplished without having to reanalyze the clip.
To display the Smoothing parameters for the Stabilize behavior
µ
In the Behaviors tab in the Inspector, choose Smooth from the Method pop-up menu.
The Translation Smooth, Rotation Smooth, and Scale Smooth parameters become available.
Reanalyzing at a Higher Quality
When analyzing, choose Better from the Quality pop-up menu in the Behaviors tab of
the Inspector. This may take longer, but the quality of the analysis is higher.
1299 Chapter 19 Motion Tracking