Adobe 25510629 - After Effects CS3 Professional, Руководство пользователя

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82 How to
In these cases, you’ll achieve the best results if the key points are very close to the problem
area, but not on top of it. To get a better look at what you’re doing and have greater precision
in positioning points, try magnifying the view of the Input Preview Monitor. For more
information, see
“Input area and Input Preview Monitor” on page 28 .
Keeping the shadow in an input clip
A semitransparent shadow cast behind or below the subject can increase the realism of a
composited shot. To preserve shadows from the input clip, use the Multiple Key Point
method and take care not to position a key point within the shadow, as shown in the
following example. For more information, see
“Multiple Key Points Method (Color Spread)”
on page 80 .
To change how pronounced the shadow is, adjust the Shadows slider in the Matte
Generation area on the Keyer tab.
To eliminate any residual color from the screen (green or blue) from the shadow, increase
Start Level.
Do not change the Shrink Matte setting, because it weakens the shadow and leaves
artifacts.
TIP
For a part of a problem area that the subject never passes in front of, masking the area
generally produces better results. For more information, see
“Cropping and spot
masking the source clip” on page 83 .
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To delete the last point you added, press Ctrl+Z. To delete all of the points, click the Clear
Points button on the Keyer tab, or press Ctrl+E.