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Chapter 5 Extra Credit 157
To remove additional “garbage” from a key, set any additional masks to Subtract mode.
Once the masks are applied, the grass (the white portion of the matte) that was left by
the keying filter is removed from the alpha channel of the elephant image.
Editing Mask and Shape Control Points
Use the following guidelines to edit mask and shape control points.
To move a control point:
m
In the Canvas, drag the point.
To add a control point:
m
Press Option, then position the pointer over the area of the mask or shape edge in
which you want to add the point, then click. You can also double-click the edge to add
a control point.
To remove a control point:
m
Select the point, then press Delete (or Control-click, then choose Delete Point from the
shortcut menu).
To create tangent handles, do one of the following:
m
While drawing the shape, drag as you add control points.
m
To create handles after a shape is drawn, press Command and drag the control point
outward.
To break tangent handles:
m
Press Command, then drag the end of a handle.
2505.book Page 157 Wednesday, June 30, 2004 5:58 PM