Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 553

The format of expressions created by the pick whip is determined by the Expression Pick Whip Writes Compact
English preference (Edit > Preferences > General (Windows) or After Effects > Preferences > General (Mac OS)). By
default, the pick whip creates compact English expressions, which use the Timeline panel's name for the properties
within an expression. Because these names are coded into the application and never change, these expressions can
work when After Effects is running in another language. Any property names that you can change are enclosed in
double quotation marks and remain the same in any language. If you don't plan on sharing your projects across
languages, you can deselect this preference. This preference does not affect effect names or effect properties.
Here is an example in compact English:
thisComp.layer("Layer 1").transform.position
Here is the same expression, not in compact English:
thisComp.layer("Layer 1")("Transform")("Position")
Note: Because the default is to use compact English, this document uses compact English in most examples and illustra-
tions.
1 Drag the pick whip to another property in the Timeline panel or Effect Controls panel.
Optionally, modify the default expression in the expression field.
2
Edit an expression manually
Click in the expression field to enter text-editing mode.
1
Note: When you enter text-editing mode, the entire expression is selected. To add to the expression, click within the
expression to place the insertion point; otherwise, you will replace the entire expression.
Type and edit text in the expression field, optionally using the Expression Language menu.
2
To see more of a multiline expression, drag the bottom or top of the expression field to resize it.
3 To exit text-editing mode and activate the expression, do one of the following:
• Press Enter on the numeric keypad.
• Click outside the expression field.
Example: Use the expression language reference to write an expression
Follow along with this example to learn how to use the After Effects expression language reference to write expres-
sions. The expression created in this example copies position values from one layer to another.
1 Create two solid layers: Solid 1 and Solid 2.
Animate the Position property values for Solid 1 using keyframes. (See "About animation, keyframes, and expres-
2
sions" on page 185.)
3 Select the Position property for Solid 2 and choose Animation > Add Expression or Alt-click (Windows) or
Option-click the property's stopwatch
transform.position
4 Type the following directly over
thisComp
button. The following expression appears by default:
:
transform.position
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