From the course: After Effects Apprentice: 09 Expressions

Overview - After Effects Tutorial

From the course: After Effects Apprentice: 09 Expressions

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Overview

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- Hi I'm Chris Meyer of Crish Design, and welcome to the After Effects Apprentice lesson on Expressions. Now normally the way you animate a layer in After Effects is you use keyframing, where you say at this time, this parameter takes on this value. You set up multiple keyframes across time and After Effects will interpolate in between them for you. When it comes time to change the animation, you need to change the keyframes. However there is another approach where you give After Effects more general instructions, such as this layer should follow what that layer is doing, but only do it half as much, well that's what expressions are, and they can come in extremely handy when you're trying to coordinate the movements of multiple parameters or multiple layers, or trying to accommodate client changes on a deadline. I know a lot of artists are a bit intimidated by expressions because they associate them with programming and math. And it is true that expressions are based on the JavaScript programming language. However, there's a wide range of extremely useful expressions that you can use on almost any job that requires little or no programming on your part, and by programming I mean typing a word like wiggle, that's as hard as it is. And as for the math part, we're talking about elementary school math, plus, minus, multiply, divide. There's even ways to get After Effects to do the math for you, so in this lesson, I'm going to be showing you these introductory expressions that I think you'll find very useful. In this lesson, I'll be covering how to create and manage expressions, how to indeed use that simple elementary school math to modify them, how to take advantage of our three favorite intermediate level expressions of linear interpolation, looping and wiggle, how to set up a user interface for your expressions, how to set up master controls where one set of sliders can control multiple layers, and how to drive your animations by sound. We also have our usual list of Quizzler challenges, and Idea Corners for how you can put these expressions to use. Now again, this is just an introductory course on expressions, we're not going to be getting into JavaScript programming, we'll not be getting all that deep or all that complex, so there's no need to worry. These are simple things you can use on many, many different jobs. If you do want to take your expression skills to the next level, however, we do have another book called Creating Motion Graphics that has a couple of chapters that will take you deeper into this great, powerful tool in After Effects known as expressions. But before I dive in, I want to show you what all can go wrong if you rely strictly on keyframes and don't take advantage of the power of expressions. So let's dive in and have some fun.

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