Time Expressions in After Effects

Denys Bondartsov

Motion Designer & Tutor

Make your first steps into expression. The easiest one is a time expression. Just apply it to any parametric option, and you will achieve the animation without keyframes.

Guide to Using Time Expressions in After Effects for Seamless Animations

In After Effects, time expressions play a crucial role in creating dynamic and time-sensitive animations. Time expressions allow you to automate and control various aspects of your animations based on the timeline. In this guide, we’ll explore the basics of time expressions and how to use them effectively for smoother animations.

Understanding Time Expressions

Time expressions in After Effects are snippets of code that link properties to the current time, creating dynamic animations. They are written using JavaScript syntax and can be applied to various properties, providing flexibility and control.

Basic Syntax

The basic syntax for a time expression is:

property + expression

For example, if you want a layer’s opacity to change over time, you can use the following expression:

opacity + time * 10

This expression will increase the opacity gradually over time.

Common Time Expression Properties

Let’s explore some common properties and how time expressions can be applied to them:

Opacity

opacity + time * 10

This expression creates a linear increase in opacity over time.

Position

position + [time * 20, 0]

This expression moves the layer horizontally over time.

Scale

scale + [Math.sin(time), Math.sin(time)]

This expression creates a pulsating effect on the layer’s scale.

Practical Examples

Example 1: Fading In and Out

1. Select your layer.
2. Press T to reveal the opacity property.
3. Alt + Click on the stopwatch icon next to Opacity.
4. Enter the expression:javascript
5. opacity + 50 * Math.sin(time * 2 * Math.PI) This expression creates a smooth fade in and out effect.

Example 2: Bouncing Scale

1. Select your layer.
2. Press S to reveal the scale property.
3. Alt + Click on the stopwatch icon next to Scale.
4. Enter the expression:javascript
5. scale + [Math.sin(time * 5) * 20, Math.sin(time * 5) * 20] This expression makes the layer scale bounce.

Conclusion

Time expressions in After Effects offer a powerful way to bring life to your animations. Experiment with different expressions and properties to achieve the desired effects. With these tools at your disposal, you can create dynamic and engaging motion graphics seamlessly.

Remember to save your projects before experimenting and have fun mastering the art of time expressions in After Effects!