User Guide

CHAPTER 5
190
Animating Layers
Audio plays only for layers in which the Audio switch is on. To preview audio alone,
see “Previewing audio” on page 153.
Standard preview This option provides a preview of all frames in your composition.
When you use this option, After Effects displays every frame as quickly as it can using the
current settings of the layer switches, composition switches, and composition resolution.
This preview generally plays slower than real time.
Manual preview Using the shuttle control, the jog control, and the current time indicator,
you can manually navigate through a composition, layer, or footage file. The current time
indicator shows the position of a frame relative to the beginning and end of a composition,
layer, or footage file. Because the current time indicator travels only a fixed distance in the
Time Controls palette, it is less precise with long compositions.
Wireframe preview This option displays a preview of the frames for all layers in your
active workspace. Each layer is represented by a rectangle or, if a still-image layer has a
mask or an alpha channel created in another program, by the outline of the mask or alpha
channel.
You can also use the Motion with Trails preview, which preserves the outline of each frame
of each selected layer so that you can see an outline trail for every frame. See the procedure
“To use the wireframe preview” in “Previewing animation” on page 191 for information
on using the Motion with Trails preview.
Setting Video Preview preferences
You can preview the contents of your Layer, Footage, or Composition window on an
external video monitor if you have a third-party device that facilitates this, such as a video
digitizing card or a FireWire port. Set the Video Preview preferences to identify the device
After Effects uses for output and to adjust the display.
To set Video Preview preferences:
1 Choose Edit > Preferences > Video Preview.
2 Set any of the options below, and click OK:
• Choose a device from the Output Device menu. If a device is available, it will appear here.
UG.book Page 190 Wednesday, February 21, 2001 12:05 PM