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Preparing to Generate Tracking Data
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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 262.
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.
Enabling Tracking in the Effect Editor
The first step in creating tracking data is to enable tracking for an effect parameter in the Effect
Editor. Once you do this, other tracking controls become available.
The basic procedure for enabling tracking in an effect parameter is simple, but there are slight
variations depending on:
• The parameter type
• Whether the effect is 2D or 3D
• Whether the effect uses standard keyframes or advanced keyframes
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For Intraframe effects, you can only enable trackers when an Intraframe object is selected.
To enable tracking for the Position, Rotation, or Scaling parameters in effects that use
standard keyframes:
t Click the Use Tracking button.