Adobe After Effects - Manual (Page 675)

Note:
Note:
Note:
To the top
If the layer, mask, or effect that you drag the pick whip to does not have a unique name in its local context, After Effects renames it. For example,
if you have two or more masks named “Mask” on the same layer, and you drag the pick whip to one of them, After Effects renames it “Mask 2”.
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 names for properties as they appear in the Timeline panel 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")
Because the default is to use compact English, this document uses compact English in most examples and illustrations.
1. Drag the pick whip to another property in the Timeline panel or Effect Controls panel.
2. Optionally, modify the default expression in the expression field.
If you use the pick whip to create an expression to refer to a layer, and that layer has the same name as another layer in the same
composition, then the targeted layer’s name changes. The new layer name is the old layer name with a numeral at the end. This change is
necessary to ensure that the expression unambiguously refers to a single layer in the composition.
Edit an expression manually
1. Click in the expression field to enter text-editing mode.
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.
2. Type and edit text in the expression field, optionally using the Expression Language menu.
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 expressions. The expression created in
this example links the Position property of Solid 2 to the Position property of Solid 1, with the movement of Solid 2 offset by 2 seconds from the
movement of Solid 1.
1. Create two solid layers: Solid 1 and Solid 2.
2. Animate the Position property values for Solid 1 using keyframes. (See About animation, keyframes, and expressions.)
671