User Guide

CHAPTER 5
194
Animating Layers
• To go to the beginning of the composition, layer, or footage, click the First Frame
button ( ).
• To go to the end of the composition, layer, or footage, click the Last Frame button ( ).
To use the wireframe preview:
1 In the Timeline window, select the layers you want to preview. To preview all layers,
make no selection.
2 Set the work area to the time span you want to preview.
3 Do one of the following:
• Choose Composition > Preview > Wireframe Preview. To display a rectangular layer
boundary instead of an alpha channel outline, press Ctrl (Windows) or Command (Mac
OS) as you choose the preview method.
• Choose Composition > Preview > Motion with Trails.
About caching
As After Effects displays a frame or compiles a RAM preview, it places each of those
displayed or compiled frames into a cache. Once the frames are cached, they display or
play back quicker because they are now playing or displaying from RAM. Currently cached
frames are designated by green bars in the time ruler.
When you advance either sequentially or nonsequentially through frames in your compo-
sition, or play back using the Standard Preview option, each of the frames is compiled and
placed into the cache, and the green bars appear in the Timeline at the point where the
cached frame occurs. When you compile a RAM preview, the frames you designate to be
included in the preview are compiled, and the green bars appear in the time ruler to
indicate which frames were cached. If you make a change to any of the cached frames in
the composition, the cache purges only the frames affected by that change. You can also
manually purge the entire cache.
UG.book Page 194 Wednesday, February 21, 2001 12:05 PM