Adobe After Effects CS4 - Manual (Page 277)

271 USING AFTER EFFECTS CS4
Animation and keyframes
Last updated 12/21/2009
You can rename trackers and track points and modify and animate their property values in the Timeline panel just as
you do for other layer properties and property groups. You must click Apply in the Tracker panel to apply the property
changes to the target.
Feature Center Position of the center of the feature region.
Feature Size Width and height of the feature region.
Search Offset Position of the center of the search region relative to the center of the feature region.
Search Size Width and height of the search region.
Confidence Property through which After Effects reports the amount of certainty regarding the match made for each
frame. In general, Confidence is not a property that you modify.
Attach Point Position assigned to the target layer or effect control point.
Attach Point Offset Position of the attach point relative to the center of the feature region.
Adjust the track point
When you set up motion tracking, it’s often necessary to refine your track point by adjusting the feature region, search
region, and attach point. You can resize or move these items independently or in groups by dragging using the
Selection tool. To help you define the area to be tracked, the image area within the feature region is magnified to 400%
while you move the region.
Track point components and Selection tool pointer icons
A. Search region B. Feature region C. Keyframe marker D. Attach point E. Moves search region F. Moves both regions G. Moves entire track
point H. Moves attach point I. Moves entire track point J. Resizes region
• To turn on or off feature region magnification, choose Magnify Feature When Dragging from the Tracker panel
menu.
• To move the feature region, search region, and attach point together, drag inside the track point area (avoiding the
region edges and the attach point), or press the Up, Down, Left, or Right Arrow key. Hold Shift while pressing an
arrow key to move by an increment 10 times as large.
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