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As with affine corner pinning, you can place the track points for perspective corner
pinning anywhere in the motion footage layer; they do not need to be in the center or in
the corner of the feature regions. For example, if you are replacing a sign on the side of a
moving bus, the edges of the sign may be partially obscured because of shadows or
objects; but a window on the bus may be visible throughout the footage. You can first
define four feature regions that are distinct and easy to track, and then move the track
points to the four corners of the sign. When the new image appears in the sign, the
Tracker/Stabilizer calculates the relative movement between the feature regions and track
points to create the correct perspective.
When you choose perspective corner pinning, the default positions of the track points form a
rectangle in the center of the motion footage layer (left). Moving each feature region extends the
rectangle in the direction of motion (center). You can place the track points anywhere in the motion
footage layer (right).
Fine-tune the motion of the individual corner pins within the Layer window by dragging
the feature regions and noting the changes in the corresponding tracking coordinates.
See "Working with the Tracker/Stabilizer Controls (PB only)" on page 306 for details on
tracking coordinates.
To define tracking regions for perspective corner pinning:
1 Size feature and search regions on separate areas that you want to track in the motion
footage layer. All four feature regions should lie in a single plane in the real world (for
example, on the side of a bus, on the same wall, or on the floor). The four track points must
also lie in a single plane, but not necessarily the same plane as the feature region.
2 Place the four track points at the locations where you want to attach the four corners of
the second layer. You can place the track points in the center, in the corner, or outside the
feature regions.
Attaching an effect to a tracked location (PB only)
You can also use the Tracker/Stabilizer to apply an effect point to a tracked location. Just as
you would attach a second layer to a tracked region, attach an effect point to a tracked
region. The effect then follows the tracked region. For information on effect points, see
"Placing an effect using effect points" on page 174.
Using Help | Contents
Using Property and Tracking Controls (PB only)
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