User Guide

257
ADOBE AFTER EFFECTS 5.0
User Guide
Using mask modes
Using mask modes, you can create complex mask shapes with multiple transparent areas.
For example, you can set a mask mode that combines two masks and sets the opaque area
to the areas where the two masks intersect.
Mask shapes that result when different modes are applied to circle mask:
A. Original masks B. None C. Add D. Subtract E. Intersect F. Difference
The following mask mode descriptions are based on interactions between two layer
masks—the top set to Add, the other set to the mask mode described:
None After Effects treats the mask as if it does not exist. The mask has no impact on the
layer or composition. This option is useful when you want to use the mask’s path for an
effect such as Stroke or Fill, but do not want it to create transparent areas in the layer. For
more information, see “Applying effects to a mask” on page 256.
Add Adds the selected mask area to the other masks for that layer, displaying all mask
contents in the Composition window. Where multiple masks intersect, the opacity of all
intersecting masks is added together.
A
B
C
DE F
UG.book Page 257 Wednesday, February 21, 2001 12:05 PM