After Effects Expressions

Chapter 6

Math Is Your Friend

Or maybe not. I flunked high school math. After that, I avoided numbers, formulas, and calculations whenever I could. Expressions enticed me back. I found that to do the really cool stuff, I had to use a little math. And I want to share that little bit with you. It’s not much, it’s not all that hard, and the payoff is immense. So I hope you’ll stay on board. And remember, you’re using a computer! Its job is to compute. It will do all the heavy lifting.

Degrees and Radians

Let’s start with something you know: there are 180 degrees in a circle. Imagine you’re a grandfather clock. Your arms and hands are the clock’s hands. It’s 3 pm, so point to the 3. Let’s call that 0 degrees. Now, point to the 6 at the bottom of ...