Join Chris Meyer for an in-depth discussion in this video Simple math, part of After Effects Apprentice 09: Expressions.
In the previous movie, I showed you where you could accidentally screw up an…expression by adding some undesired text onto the end of it.…Just some garbage characters, Enter, and I get this error message. I'll undo.…However, there are times when you do want to edit an expression.…For example, you may want to perform some very simple math, like make something…go faster, slower, bigger, or smaller.…Let's start with rotation.…Let's say that I want the red pulley to rotate twice as fast as the blue pulley is.…
I will press the asterisk key to signify multiply.…Yes, you kind of have to use computer math, not real calculator math here,…and then 2 for times 2.…Press Enter and you can already see that where the first layer is at 2.6…degrees, my expressed layer is twice of that, 5.2 degrees.…I will RAM preview and now that red pulley is indeed spinning twice as fast.…Let's say that instead you want the pulley to go half as fast.…Well, that's simple.…
Rather than asterisk, or times 2, you do a slash or divided by 2.…
The After Effects Apprentice series was created by Trish and Chris Meyer. These tutorials are designed for After Effects CS4 through CC, and can be used on their own or as a companion to the Meyer's book, After Effects Apprentice.
- Creating and managing expressions
- Linking together different parameters
- Randomizing a layer's movement
- Looping an animation
- Controlling multiple layers from a single source