Adobe After Effects CS4 - Manual (Page 555)

549 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
the original image. Erasures remove only painting strokes; that is, they re-reveal the underlying image within the alpha
channel.
K. In Original Alpha Only The original image appears within its alpha channel in working view. Strokes affect the alpha
channel itself. Painting adds areas of opacity. Erasures add areas of transparency.
Note: You don’t need to switch colors when you paint in the alpha channel, even if you paint with gray. The changes to
the opacity of the painted area are determined by the values shown for Opacity and Feather under Brush Settings in the
Effect Controls panel, not by the color of paint.
L. Under Original Alpha Only The original image appears within its alpha channel in working view. Strokes don’t affect
the original image alpha channel, only areas outside it. Painting adds areas of opacity; erasing restores transparency to
painted areas only.
Note: The difference between using Under Original and Under Original Alpha Only is that in the latter, strokes affect
only the alpha channel; RGB is unchanged.
Select Vector Paint preferences
Use the Vector Paint Preferences dialog box to customize the way you view your work in Vector Paint. Unlike most
other effects, the options you select as Vector Paint preferences apply to all your Vector Paint work, both on the current
layer and on other layers. Your current preferences are also used for subsequent sessions of Vector Paint.
1 Select Vector Paint in the Effect Controls panel and open the Vector Paint Preferences dialog box in any of the
following ways:
• Click the menu button in the Vector Paint toolbar in the Composition panel, and choose Options.
• Right-click (Windows) or Control-click (Mac OS) anywhere in the Composition panel, and choose Options.
• In the Effect Controls panel, click Options to Vector Paint.
2 Choose the appropriate options.
Note: Better Preview While Drawing is temporarily disabled in low-memory situations, and Draft quality is used instead.
Also, if the preview doesn’t draw correctly, you may have an incompatible video card.
Perspective effects
3D Glasses effect
The 3D Glasses effect creates a single 3D image by combining a left and right 3D view. You can use images from 3D
programs or stereoscopic cameras as sources for each view.
The method you use to create the combined images dictates how you view them. For example, you can use 3D Glasses
to create an anaglyphic image, which is an image containing two slightly different perspectives of the same subject that
are tinted contrasting colors and superimposed on each other. To create an anaglyphic image, first combine views and
tint each one a different color. Then, use 3D glasses that have either red and green lenses or red and blue lenses to view
the resulting image stereoscopically.
This effect works with 8-bpc color.