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Preparing to Generate Tracking Data
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Applying an Effect for Motion Tracking
You apply an effect for motion tracking in the same way that you apply any effect that either
operates on a multilayer sequence or lets you draw a foreground object on top of a video layer.
For more information, see “Applying Effects” on page 33.
Making Non-Tracking Parameter Adjustments to an Effect
The final look of an effect that uses tracking is typically the result of combining the tracking data
with standard effect parameter adjustments. You usually need to define the appearance of the
effect in the first frame or field of the segment, and you might also need keyframe adjustments at
other points in the segment.
In most cases, you can choose whether to make these adjustments before or after you generate
the tracking data. As long as the standard adjustments as well as the tracking data are in place
when you play the effect, you see the final result of all the adjustment data.
For example, if you are replacing a sign on a moving vehicle, you use standard effect parameter
adjustments to set the initial size, shape, and position of the sign. Depending on the complexity
of the material, you might make these adjustments using basic parameters such as Position and
Scaling, or you might place each corner independently using the Corner Pin parameter.
If you want the effect to be offset from the moving area that you plan to track, you establish the
offset by adjusting the Position parameters. The final motion of the effect maintains that offset
from the tracking data points as it moves. If you want the size of the effect to change in a manner
that is not dependent on changes in the moving area, you can set up that change in size by using
keyframes and the Scaling parameters.
When you work with Intraframe effects, you must draw the foreground object that you want to
control with tracking information and select it with the Selection tool before you can generate
tracking data. As with other effects, however, you can establish the precise size, shape, and
position of the object either before or after generating tracking data.
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You can choose which frame in a tracked segment is the reference frame (the frame at which the
tracking data makes no change to the look of the effect). For more information, see “Setting the
Reference Frame for a Tracker” on page 337.
Preparing to Generate Tracking Data
The topics in this section cover procedures that you need to follow before you can generate
tracking data. These procedures control how the system operates as it creates the tracking data.