I have numerous expressions tucked away in my head, and haven’t the faintest idea about JavaScript. While the language is based on the JavaScript language, you don’t need to know JavaScript to get started with expressions.

If you’re emulating the light flicker from a candle using a solid color and adjusting its opacity, the wiggle expression is perfect for replicating the sporadic nature of a flickering flame. This is a lot faster than tediously animating the media item back and forth, or continually lowering the opacity or scale.Īs noted in the examples above, although the wiggle expression is usually applied to an object’s position, there are numerous applications for the wiggle expression. With that covered, what about in the case of the wiggle expression? With a wiggle, we’re instructing the property, whether the scale, opacity, or position, to wiggle within the set parameters. An example of a script-not an expression. For example, this script tells the application (the application being After Effects) to position the anchor point of this layer to the center, the right, or the top.

Now, unlike a script, which tells the application to do something, an expression will inform the individual property to do something. First, before we look at what the wiggle expression does, we must ask: What is an expression? An expression is a piece of JavaScript code that you can insert into the animated properties of your media.