(Week 11) Discussion, (Some) Principles of Animation

Introduction & Context

This week we'll talk about a few of the principles of animation. The goal will be to help you define how any images, text, characters or content transition between frames, and give us some common language in order to do that.

What are the principles of animation?

The Principles of Animaiton were created by Disney animators and codified in the book The Illusion of Life, they are not hard and fast rules, and they apply generally to character based animations.

Squash and Stretch

Squash and Stretch is generally meant to encompass the idea that forms will be exaggerated by the intensity of their action, or the mass/implied material of person or thing doing the action.

As cartoon characters are generally more "rubbery" or malleable, they might squash or stretch more in order to emphasize their action, especially with limited frames.

Anticipation / Slow In and Slow Out

Anticipation and Slow In & Slow Out are separate principles around a similar idea. The overarching idea being that most motion is non-linear.

Linear motion is when all frames between the start and endpoint of a given transformation are the same. If you look at the gif below, the red (top) ball's "shadow" or trail is even, whereas the other ones get darker at the beginning and end in different ways based on different patterns of what is called easing.

image from erraticgenerator.com showing different types of easing or interpolation

Secondary Action

Secondary action allows you to show the influence of motion on other elements of the animation. That is to say if someone moves, what happens to their hair? cape? boots? If they begin running do they get pushed backwards? If they stop spinning, is their hat still rotating a little?

image from school of motion showing a chicken with and without secondary motion

Here's the whole series as covered by Alan Becker's channel:

How to apply the principles

The principles allow you to convey more complex ideas visually, more effectively, with fewer resources or time.