Apple Motion 4 - Manual (Page 1320)

Auto-Zoom Mode: This parameter appears only when there is a tracking source (footage)
in the source well. Choose an option from this pop-up menu to set the display of the
auto-zoomed tracker in the Canvas. There are three choices:
• Normal: Displays a normal pattern.
• Contrast: Displays the tracker pattern with contrast detection.
• Edge: Displays the tracker pattern with edge detection. The Auto-Zoom Mode applies
only to the trackers in the Canvas and does not appear in the Tracker Preview in the
Behaviors tab of the Inspector. When None is chosen from the Auto-Zoom pop-up
menu, the Auto-Zoom Mode setting has no effect.
Look Ahead Frames: This parameter appears only when there is a tracking source (footage)
in the source well. This slider and value slider allow you to specify the number of “future”
frames to be analyzed by the tracker. In other words, you can direct the tracker to look
in a specific location for its reference point. This is especially useful for footage that
contains fast-moving objects, as the reference point can quickly “get away” from the
tracker. For more information on using Look Ahead Frames, see
Giving Motion a Hint .
Track list: Tracks appear only when there is a tracking source (footage) in the source well.
Displays the trackers in the behavior as “Track 1, Track 2,” and so on. The number of
trackers is determined by the number of control points on the shape with the applied
Track Points behavior. For example, when a Track Points behavior is added to a shape
with 12 control points, 12 trackers will appear in the track list.
When another track is referenced, the track list is replaced with Control Point pop-up
menus.
To disable a tracker, deselect its checkbox. To remove a tracker, click the Remove button.
A tracker that is turned off is not analyzed with the track.
Click the disclosure triangle next to the track name to reveal additional parameters:
• Position: Displays the X and Y positions of the tracker. The X position is the value slider
on the left; the Y position is the value slider on the right. Click the disclosure triangle
to display labeled position value sliders.
• Track Size: Use this slider to adjust (in pixels) the pattern search size for the tracker. As
you adjust the track size, the Tracker Preview is updated to show the new track size
(there is no visual change in the Canvas tracker).
To adjust the Track Size without exposing its parameters, Option–drag left in the Tracker
Preview area to reduce the track size; Option–drag right to increase the track size.
• Search Size: Use this slider or value slider to increase or reduce the tracker’s search area
size. In Motion, you do not specify the size of a search area when setting up your trackers
in the Canvas. To change the default search size, use the slider or value slider. If Search
Size is set to 200 percent, the tracker’s search area is twice the default search area size.
1320 Chapter 19 Motion Tracking