3

110 Chapter 2 Motion Tracking
Transform: This pop-up menu allows you to choose how the destination object moves.
 Attach to Source: This option “glues” the destination object to the recorded track or
animation source. Use Attach to Source when the source object is scaling or rotating,
and you want the destination object to “stick” to a particular spot on the source
object. Any animation that existed on the destination object prior to applying the
track is erased.
Note: Although the destination object is attached to the movement of the source
object, the destination object can be offset from the source object.
 Mimic Source: This option allows the destination object to “mimic” the recorded
track or animation source. Any animation that existed on the foreground object prior
to applying the track is added to the track.
Note: As with Attach to Source, the destination object can be offset from the source
object.
Align Tangents: When this checkbox is turned off, tangents remain aligned at their
original angles. When turned on, the tangents match the transformation of the source
animation, and the shape changes its form.
Movement: The Movement parameter contains controls to begin the tracking analysis
and to specify the direction of the analysis.
 Analyze: Click the Analyze button to begin the motion tracking analysis. Once
Analyze is clicked, a status window appears that displays the tracking progress. To
stop the analysis, click the Stop button in the status window or press Esc.
The start of the track is based on the current playhead position, rather than the start
of the behavior in the Timeline.
 Reverse: When the Reverse checkbox is turned on, the clip is analyzed from the
current playhead position to the first frame of the clip (or the first frame of the
tracking behavior).
Note: You must move the playhead to the frame where you want to begin the
reverse analysis.
For a description of the Tracker Preview, Offset Track, Auto-Zoom, Auto-Zoom Mode,
Look Ahead Frames, and track list parameters, as well as the tracker subparameters, see
“Tracker Controls” on page 112.
For information on using the Track Points behavior, see “Track Points Workflow” on
page 76.
Track Parameter Behavior Controls
The Track Parameter behavior allows you to track a position parameter of a filter to a
reference feature of a clip, or to apply existing tracking data to a position parameter of
a filter.