Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 556

• Type at the beginning of the comment and
/*
ignored. For example:
/* This is a
multiline comment. */
Save and reuse expressions
Once you have written an expression, you can save it for future use by copying and pasting it into a text-editing appli-
cation, such as Notepad, Simple Text, or even Stickies. However, because expressions are written in relation to other
layers in a project and may use specific layer names, it doesn't always work to simply transfer expressions between
projects.
If you want to save an expression for use in another project, you should add comments to the expression. You should
also use variables so that you can change a value in one place rather than having to change it in several places.
For example, this expression has a multiline comment at the beginning that explains what the expression does and a
short comment after a variable is declared and initialized that tells what the variable is for:
/* This expression on a Source Text property reports the name
of a layer and the value of its Opacity property. */
var myLayerIndex = 1; // layer to inspect, initialized to 1, for top layer
thisComp.layer(myLayerIndex).name + ": \rOpacity = " +
thisComp.layer(myLayerIndex).opacity.value
You can save an animation preset that includes an expression and reuse it in other projects, as long as the expression
does not refer to properties that don't exist in the other projects. When you save a preset in which a property has an
expression but no keyframes, only the expression is saved. If the property has one or more keyframes, the saved
preset will contain the expression along with all keyframe values.
You can copy an expression from a layer property, with or without the property's keyframes. Copying an expression
without keyframes is particularly useful when you want to simultaneously copy multiple expressions and paste them
onto one or more new layers, or when you want to copy one expression and paste it onto more than one layer.
• To copy an expression and keyframes from one property to other properties, select the source layer property in
the Timeline panel, copy the layer property, select the target layer properties, and paste.
• To copy an expression from one property to other properties without copying keyframes, select the source
property, choose Edit > Copy Expression Only, select the target properties, and paste.
Note: As with pasting keyframes and other items, you can often paste the item into the target layer and rely on After
Effects to determine which property should be the target of the paste operation. For example, this works for copying
Position properties from one layer to another, but you must select the target property yourself if you are pasting an
expression from a Position property into a Scale property.
See also
"Save an animation preset" on page 352
"Work with layer properties in the Timeline panel" on page 155
at the end of the comment. Any text between
*/
AFTER EFFECTS CS3 550
User Guide
and is
/* */