Apple Motion 4 - Manual (Page 1250)

When the tracker’s position and correlation values for a given frame have been determined,
Motion records this information in keyframes. This process is then repeated for every
frame, until the end of the track range has been reached.
The recorded data is stored as keyframes in the tracking behavior. The data allows you
to quickly apply the tracks to many project elements.
Note: The Stabilize behavior uses an advanced technology that analyzes the motion of
the entire frame of a clip, without the use of trackers.
There are six tracking behaviors in Motion: four in the Motion Tracking behaviors
subcategory, one in the Shapes behavior subcategory, and one in the Parameter behaviors
subcategory.
Motion Tracking Behaviors
Motion uses behaviors to collect, store, and apply the motion data. Because the data is
stored within the behavior (as keyframes), it can easily be applied to other objects within
a project. A Motion Tracking behavior can also be used to share animation data that is
created by behaviors or keyframes between objects. The Motion Tracking behaviors are
applied in the same manner as all other behaviors.
When a tracking behavior performs its analysis, track points appear in the Canvas, and
tracking keyframes are created within the behavior. These keyframes live within the
behavior that is applied to an object—the keyframes are not applied to the object itself.
Note: Onscreen track points (and their corresponding tracking keyframes that appear in
the Keyframe Editor) are not created when using the default motion analysis in the Stabilize
behavior.
When applicable, you can convert tracking data that is recorded or referenced by the
Match Move, Stabilize, or Unstabilize behavior to object keyframes. When converted, the
tracking behavior is removed and the transform keyframes are “baked” into the object.
For more information on converting behaviors, see
Converting Tracks to Keyframes .
There are four Motion Tracking behaviors:
• Analyze Motion: This behavior is used only to generate and contain tracking information
from a clip. Unlike the Match Move and Stabilize behaviors, Analyze Motion has no
capability to alter the object being tracked. The tracks gathered by the Analyze Motion
behavior can be applied to other project elements via the Match Move, Track (in the
Parameter behaviors), and Track Points (in the Shape behaviors) behaviors.
Note: The Analyze Motion behavior can only be applied to footage (a QuickTime movie
or image sequence).
The Analyze Motion behavior can generate as many trackers as you like.
1250 Chapter 19 Motion Tracking