Join Chris Meyer for an in-depth discussion in this video Expressions, part of After Effects CS4: Apprentice's Guide to Key Features.
One of the most powerful features in After Effects is Expressions.…An Expression is a small piece of code that allows the parameter of one layer or…one effect to follow another parameter or another layer or another effect,…whatever you choose. It can be thought as an alternative to keyframing. Rather…than having to copy and paste keyframes, you can just express one parameter to…follow another parameter.…For example, here I have already keyframed the blue pulley and now I want to…make the red pulley follow along. Well the first thing you need to do is reveal…the parameters you wish to express. I have already got Scale and Rotation…revealed for the blue pulley. I will select the red pulley, type S to reveal…its Scale, then Shift+R to also add its Rotation value.…
To enable Expression, I will hold down the Option key on Mac or Alt key on the…Windows and click on the animation stopwatch. Once I do so, you will see an…extra line gets revealed in the Timeline panel. The Expression for Scale.…And After Effects will write a dummy initial Expression for me, basically saying,…
After Effects CS4: Apprentice's Guide to Key Features is a series of guided tours with Chris and Trish Meyer. It is designed as a gentle introduction to some of the major features of After Effects CS4. This quick–start course is for beginners who already know how to animate, users who are not familiar with the latest version, or those who need to get up to speed with advanced tools. Chris and Trish cover features such as text animators, shape layers, expressions, and motion tracking. These guided tours are also included with the second edition of Chris and Trish Meyer's book, After Effects Apprentice (Focal Press).
To learn the basics of animating in After Effects CS4, check out After Effects CS4 Getting Started with Chad Perkins in the lynda.com Online Training Library®. To go deeper, see Chad's After Effects CS4 Essential Training. To get an overview of the new features in After Effects CS4, watch After Effects CS4 New Creative Techniques with Chris and Trish Meyer.
To purchase After Effects Apprentice—the book—go to www.amazon.com.
- Understanding 3D Axis Arrows and Camera Tools
- Working with Text Essentials and Animators
- Using Tracker controls