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The rotation in the first layer is defined by two feature regions and the axis that runs
between them. An arrow on the axis points from the first feature region to the second. The
Tracker/Stabilizer tracks the rotation by measuring the angle of the axis in relation to the
first feature region: as either feature region moves, the angle of the axis changes. Note that
even if the objects tracked inside both feature regions are moving up, down, or across, the
Tracker/Stabilizer tracks only the relative rotation between the regions, not the overall
movement. Because the second layer is not attached to the first, there is no track point.
To define tracking regions for rotation:
1 Place the first feature region (on the left by default) over the object you want to specify
as the base of the axis. Rotation is measured relative to the center of this region. If the
object is moving, size the search region appropriately.
2 Place the second feature region over the object that defines the angle of rotation. Size
the search region appropriately.
Tracking position and rotation (PB only)
When you track both position and rotation, you attach a layer to a single track point, so
that the attached layer not only follows the tracked region but also duplicates the
rotation. This type of tracking is useful when the feature regions contain a lot of motion.
With position and rotation, the track point is fixed in the center of the first feature region.
To adjust the position of the attached layer, adjust its anchor point after applying the
tracking.
To define tracking regions for both position and rotation:
1 Size the first feature region (on the left by default) over the object you want to track.
The second layer is attached to the center of this region. This region defines the base of
the axis.
2 Size the second feature region over the object that defines the angle of rotation.
3 Size both search regions appropriately.
Tracking position using affine corner pinning (PB only)
When you track position using affine corner pinning, you simultaneously track three
points in a motion footage layer with three points in a second layer. The position of a
fourth, inactive point is determined by the three active points. As the three points move,
the layer is distorted to simulate skewing, scaling, and rotation, but not perspective.
Parallel lines remain parallel, and relative distances are preserved. For example, suppose
that you have footage shot by a handheld camera that zoomed in or out during shooting
but remained perpendicular to the background; you want to replace the background.
Using affine corner pinning, the Tracker/Stabilizer calculates the relative movement
between the feature regions and track points to create the correct scaling of the
background.
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Using Property and Tracking Controls (PB only)
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