Apple Motion 4 - Manual (Page 1307)

• Fail Behavior: This pop-up menu specifies what happens if the track confidence value
falls below the Fail Tolerance amount. The following options are available:
• Smart Retry: The tracker attempts to find the reference pattern in a larger search area.
If the pattern cannot be found, the tracker switches to the Predict option. Smart Retry
is the default fail behavior.
• Stop: Stops the analysis when the tracker loses the reference pattern. You can also
click the Stop button in the tracking progress dialog or press Esc to stop an analysis.
• Predict: The tracker predicts a new search area without creating keyframes until it
finds a match for the reference pattern. This is excellent for tracked objects that pass
behind foreground objects.
• Predict and Key: If a failure is detected, the tracker predicts the location of the keyframe
based on a vector of the last two keyframes, and continues tracking in the new area.
• Don’t Predict: The tracker remains in its position and searches for subsequent matches
as the clip’s frames progress. While searching for a match, the tracker does not create
keyframes.
• Use Existing Keyframes: Use this option if you have manually created track position
keyframes to guide the tracker. After manually adding keyframes, return to the start
frame and start the tracking analysis. If the tracker has difficulty locating the track
pattern, the manually created tracking keyframes are referenced to guide the tracker.
• Color: Click or Control-click the color well to set a new color for the onscreen tracker.
You can also click the eyedropper and select a color in the Canvas. The default tracker
color is red. When a tracker is selected, its center point is yellow and the border of its
magnified inset is the color set in the color well. To adjust the individual color channels,
including the tracker’s opacity, click the disclosure triangle.
HUD Controls
The Analyze Motion HUD contains controls to start the motion track (the Analyze button),
reverse the direction of the track (the Reverse checkbox), and to specify an offset track
(the Offset Track checkbox). Offset tracking allows you to reposition the tracker at a new
reference pattern.
Match Move Controls
The Match Move behavior can be applied to many different object types, including groups,
cameras, shapes, particle emitters, and so on.
Important: When applying the Match Move behavior to a group, make sure that the
footage being analyzed resides outside of the group being tracked.
In order to use Match Move (and access all of its parameters), your project must contain
a foreground and a background object. For information on using the Match Move behavior,
see
Match Move Workflows .
1307 Chapter 19 Motion Tracking