Adobe After Effects

Modifying Expressions

The expression menu is great because it limits the risk that an expression will fail based on a typo. But even with using prebuilt expressions, we’ve quickly seen the power of modifying those expressions. Let’s go a little further into how we can write and change expressions to suit our needs.

Time

Let’s say I want a shape to continuously rotate throughout the duration of my comp. Normally, that’s a keyframe at the start of my comp and another at the end. If the length of my comp changes, or I want to change the shape’s starting rotation, I’ll have to redo one or both keyframes to get the speed I want. This is annoying! However, the time expression is a quick way to plug the value of your composition’s time into any parameter. ...