After Effects expressions
From Mographwiki.net
What are expressions?
Expressions in After Effects utilize a scripting language similar in syntax to Javascript/Flash Actionscript in order to manipulate layer properties and effects through mathematical equations. Property values can drive other property values. For example the rotation of one layer can drive the opacity of another.
Expressions are applied by alt-clicking the stopwatch of a property. You can type any number, equation, or predifined function (such as wiggle) in this text field. To complete editing an expression hit enter on the keypad. For example, applying this expression to the position property of a layer makes it wiggle:
wiggle(5,40); //wiggle this layer 5 times a second by 40 pixels
Resources
- JJ Gifford - An in depth look at some of the mathematics behind expressions.
- MotionScript - The home of Dan Ebberts. Here you will find explanations of the maths and lots of examples of the code being used. A first stop for anyone getting into expressions.
- Creative Cow - After Effects Expressions - Lots of tutorials on setting up different expression driven effects. Dan Ebberts is a huge contributor to these tutorials.
- AE Enhancers -A forum dedicated to expressions and scripting in After Effects. A vast collection of experiments and tutorials.
- Beginners tutorial about expressions by Graymachine
- After Effects Expressions Series 1 - An hour-long video on After Effects Expressions by Harry J Frank available at Toolfarm.
- Colin Braley - Several expressions-based tutorials.
