Adobe 65008009 - After Effects CS4 Using Manual page 89

Last updated 12/21/2009
• To remove unselected compositions and unused footage items from selected compositions in the Project panel,
choose File > Reduce Project. This command is available only when the Project panel is active.
This command removes both unused footage items and all other compositions that are not included within a selected
composition as nested (subordinate) compositions.
If the selected composition includes items that are turned off (that is, the Video or Audio switch is deselected in the
Timeline panel), the Reduce Project command does not remove those items.
If an expression in a selected composition refers to an element in a nonsubordinate composition, Reduce Project
removes the nonsubordinate composition and the applied expression. A message appears after you choose Reduce
Project to remind you of this possibility, so you can undo the command if needed. To avoid removing the expressions
from a nonsubordinate composition, drag the nonsubordinate composition into the composition that refers to it. Then
deselect the Audio and Video switches for the composition that you added.
Placeholders and proxies
When you want to temporarily use a substitute for a footage item, use either a placeholder or a proxy.
A still image of color bars used to temporarily take the place of a missing footage item. Use a placeholder
Placeholder
when you are building a composition and want to try out ideas for a footage item that is not yet available. After Effects
generates placeholders automatically, so you do not have to provide a placeholder footage item.
Any file used to temporarily replace a footage item, but most often a lower-resolution or still version of an
Proxy
existing footage item used to replace the original. Often, storyboard images are used as proxies. You can use a proxy
either before you have the final footage or when you have the actual footage item but you want to speed up previewing
or rendering of test movies. You must have a file available to use as a proxy.
Any masks, attributes, expressions, effects, and keyframes that you apply to the layer are retained when you replace its
placeholder or proxy with the final footage item.
In the Project panel, After Effects marks the footage name to indicate whether the actual footage item or its proxy is
currently in use:
• A filled box indicates that a proxy item is currently in use throughout the project. The name of the proxy appears
in bold type at the top of the Project panel when the footage item is selected.
• An empty box indicates that the footage item is in use throughout the project, though a proxy has been assigned.
• No box indicates that no proxy is assigned to the footage item.
USING AFTER EFFECTS CS4
Importing and managing footage items
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