The Wave Principle: In Theory & Practice

Alex Carey
3 min readJul 29, 2019

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Recently I’ve been working on a lot of frame by frame animation and am using the wave principle constantly. It’s so fundamental and I wanted to share it to reinforce what I know and learn some new things along the way.

I’ll first break down why the wave principle works in theory and then teach you how to put it into practice.

In Theory

The wave principle is essentially a series of arcs.

Arcs are important because they are a natural and fluid movement. More things than you realize move in arcs.

Some examples of arcs from Richard Williams’s book The Animator’s Survival Kit.

Arcs create fluid movement because it’s how we expect things to move. Our brains are rewarded because we know what’s going to be in the next frame. It feels good.

In Practice

The wave principle is applied when an arc moves through an object.

You have one end that’s leading the action and the movement flows through the object until it reaches its end.

Let’s take this animation of a guy with an abnormally long tongue.

suns out tongues out! 😛

Here it is broken down into its most basic components.

The tongue is made up of two points. We’ll call the blue ball the leading point, and the red ball the following point. The wave will start from the leading point and the motion from the leading point will be carried through the object.

Now that we understand the relationship between the leading point and following point let’s look at drag and overlap.

Drag — is when the following point is trailing behind the leading point.

Overlap — is when an object’s momentum propels the following point past the leading point.

Above I have marked out the points where the following point drags and overlaps. When the shape overlaps it creates an S-curve. The line connecting the two looks like an S and these arcs give our motion some life!

Overlapping action makes our animation more interesting because everything isn’t moving at the same time. One thing arrives first and the rest has to catch up, in life everything doesn’t move at the same pace.

These arcs will end up creating a figure 8. This helps create the path for the following point.

Combine Drag and Overlap, the S-Curve, and the Figure 8 to create your own wave. Get creative and show me!

As usual, if you have any questions feel free to ask. All of the principles taught in this were learned for Henrique Barone’s Traditional Animation class and Richard Williams’s The Animator’s Survival Kit.

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Alex Carey

I’m a designer and animator in Los Angeles. You can find my work at alexcarey.co