5.1.1

Chapter 22 Motion tracking 957
You can apply the recorded data, stored as keyframes in the tracking behavior, 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.
Tracking behaviors
Tracking behaviors overview
There are six tracking behaviors in Motion: four in the Motion Tracking behaviors subcategory,
one in the Shape behavior subcategory, and one in the Parameter behaviors subcategory. You
apply these behaviors like any other behavior in Motion. For a general overview of Motion
behaviors, see Behaviors overview on page 293.
Motion uses behaviors to collect, analyze, store, and apply tracked motion data. Because the data
is stored in the behavior (as keyframes), it can easily be applied to other objects in a project. A
tracking behavior can also be used to apply animation data created by standard behaviors or
keyframes. 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 in the behavior. These keyframes live in 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. For information about the Stabilize behavior, see Motion Tracking on page 957.
For information about specic tracking behaviors, choose a topic in the Help table of contents
(the sidebar to the left of this window).
Motion Tracking
There are four Motion Tracking behaviors, accessible in the Add Behavior pop-up menu:
•
Analyze Motion: This behavior is used to generate and store tracking information from a clip.
Unlike the Match Move and Stabilize behaviors, Analyze Motion cannot apply its tracking
information to other objects. However, the tracks gathered by the Analyze Motion behavior
can be applied to other objects via the Match Move, Track (in the Parameter behaviors
category), and Track Points (in the Shape behaviors category) behaviors. The Analyze Motion
behavior lets you add multiple trackers to a clip. In this way, you can analyze multiple
reference patterns at the same time. The Analyze Motion behavior can only be applied to
footage (a QuickTime movie or image sequence).
•
Match Move: This behavior is used to match a foreground element to a background element so
they appear locked together. This eect can be achieved in three ways:
•
You can match a foreground element to a background element using one-point (position),
two-point (position, scale, or rotation), or four-point (corner-pinning) tracking. Unlike other
tracking behaviors, the Match Move behavior can perform the analysis and compositing
operations. You can add further modications (blur, color corrections, and so on) before you
create the nal composite.
•
You can use the Match Move behavior to apply a reference a track recorded by another
tracking behavior. You do this by choosing a track from the Action pop-up menu (the gear
icon) in the Match Move behavior’s HUD or Inspector.
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