Description
Expressions are quick scripts that can affect modify input values, from the expression itself or another object in AE, and then apply them to a specific Layer property. Expressions can be static throughout time or dynamicly changing as time progresses.
Adding an Expression
To Activate an expression:
- Select and expand the layer target layer's properties
- Locate a specific property, for example, scale
- hold down ALT and left click the little stopwatch near the property
- (notice the text box that appears where keyframes should go?)
- you can delete the default text and substitute a value of your own. 50 for example.
Try the following expressions
[50, 50]
[50+10, 50-10] x=25; [50, x]
x=5; y=60; [x+y, x-y]
[random(1, 100), 100]
- remember text values need "text" with quotations, while numeric values need numbers, Also if a property has 2 values, your expression should return 2 values as well.
Examples
For example you may want to may a layer's opacity jitter a bit, so you might