Wiggle Effect. Tutorial 3.

http://library.creativecow.net/articles/ebberts_dan/ae6_exp.php

Expressions are one of the interesting functions in After Effects. For example we can use wiggle effect to create a sense of liveliness and motion.

In order to make an object move randomly we need to use a wiggle expression. Wiggle expression can be placed on any transformation property. It can be places on rotation (and the object will rotate randomly), or position, or opacity and so on.

In order to place an expression on a position we need to command+shift click on the stopwatch. And when we get a line to place our expression we write wiggle(5,25). We can write any number according to our needs. The first number is the amount of wiggle movements or changes in the property per second. The second number is the amount of pixels, or values. 25 means that the range of the change is going to be from -25 to 25 pixels.