Free 3D training | Disney’s 12 principles of animation: follow-through and overlapping action

Master Disney’s 12 classic principles of animation in 3D with Steve Lambert’s regular series of articles on the fundamentals of CG. This week: follow-through and overlapping action

This week Weta Digital’s animation director Steve Lambert explains how to apply the fifth classic principle to your animation: follow-through and overlapping action. (To find previous topics scroll to the bottom of this post.)

FOR: Any software | TIME TAKEN: 3 hours | TOPICS COVERED: Follow-through and overlapping action | ALSO REQUIRED: Maya (to view scene files)

Download the project and animation files for this training: 
fundamentals_5.zip (12.7MB)

Follow-through and overlapping actions are to some degree part of the same phenomenon.

Follow-through is the movement following the termination of an action. When kicking a ball, for example, the foot’s swing doesn’t stop the second it contacts the ball: it continues in an arc. Similarly, when a car stops abruptly, the passengers in that car are still thrown forward – they do not stop at the same time as the car.

Overlapping actions are those that begin before previous actions have finished, or where the direction of movement changes – some parts may continue on their original course until they catch up with the change in direction.

As a general rule, the targets for these principles divide into two main groups: active and passive.

The passive group is anything that is driven purely by adhesion, constraint or influence from an initiator – for example, hair attached to the scalp by its roots or clothes wrapped around the body.

Watch the three clips included in the download to see how these principles help to keep your animations fluid

They have no choice but to follow the movements of their initiating force, and react mainly to gravity and atmosphere. Those in the active group have some control over their movements. They include arms, legs and tails: objects that can be passive, but also have the ability to behave in more controlled ways.

The exaggeration of these principles is dependent on their weight and their environment. Under water, for example, passive objects waft about in a different manner to on the surface. A common mistake is making things look like they’re underwater when they’re not! This results in a wafty, rubbery animation that lacks solidity.

I’ve used three clips featuring a boy character and a couple of props to help describe the principle. You can find these movies in the download folder.

In the first clip (Overlap_01.mov), the character starts walking with all of his body moving at once.

His arms and legs are exactly in time, as are all the other movements of his body. His bucket and fishing rod are stiff and wooden, with no sense of weight or flexibility. He stops abruptly, bringing everything to a halt at once.

In the second clip (Overlap_02.mov), I’ve focused on his body movements.

When he starts to walk, his body leads with his hips; his looser limbs fall behind slightly. His elbows lag behind his shoulders, and his wrists behind his elbows.

By overlapping the rotations of his arms and offsetting them from the movement of his legs, he has become much more flexible.

The same goes for the rest of his body: his head has a sense of weight as it rolls about slightly behind the shoulders. When he stops, his body stops in stages. The amount of exaggeration determines the emphasis of his halt.

Secondary movements illustrating the principles of follow-through and overlapping are shown in the third clip

In the third clip (Overlap_03.mov), I’ve added the secondary movements of his bucket and fishing rod.

• Learn more about how secondary animation can breathe life into your CG characters. Check out issue 156 of 3D World

By having the ‘joints’ in the rod bend with overlapping rotations, you get the sense that the shaft is highly flexible.

The bucket now feels like it’s loose and light, and the fish is at the mercy of gravity and inertia – especially when the boy stops suddenly. These actions are vital to keeping your animation fluid.

To see the examples of these animation principles in action download the fundamentals_5.zip

Next week we’ll show you how to achieve prefect timing in your animations using the sixth classic principle: slow in and slow out.

Topics online:

• Squash and stretch
• Anticipation
• Staging
• Straight ahead and pose to pose

Coming up online:

• Slow in, slow out
• Arcs
• Secondary action
• Timing
• Exaggeration
• Solid design
• Appeal

Tutorial credits
This tutorial uses the ‘Andy’ rig created by John Doublestein for the Savannah College of Art and Design.

Want to learn more about animation?

• Check out our animation course special on SCAD
• Learn more about the recent Animation issue of 3D World featuring some of the top animation schools
• Read 10 best animation tips and tricks

(This article was first published in issue 121 of 3D World, October 2009.)

About the author
Steve Lambert has been working in the CG industry since 2001. Currently director of animation at Weta Workshop in New Zealand, his recent feature film work includes Prince Caspian and Avatar
scoobasteve.co.nz