Followthrough and Overlapping Action

According to Newton's first law, "objects in motion tend to stay in motion." This is true even in animated worlds. If a puppy with floppy ears was running, then he suddenly stopped, it would feel strange and unnatural if his ears stopped with him. In reality, if the puppy tried to stop, his rear end would keep going forward, and so would his floppy ears.

What is Followthrough and Overlapping Action?

These are two different types of movement that are similar, but they are not the same.

Followthrough: This part of the principle explains that once part of an object or character stops, other parts of it keeps going, much like Newton says in his first law. Also, if one part of an object or character moves in a specific direction, the principle of Followthrough says that other parts of the object will follow [1]. The different parts can be ears, tails, arms, hair, clothing, and many other extensions of the main body [1]. Edmond will help explain.

Edmond is happily hopping along, when he sees a giant cliff! He must quickly stop before he falls over the cliff. As Edmond is trying to slow down, he is fighting against his momentum--the force that he had built up by moving forward. Although his front to legs have stopped, Followthrough keeps some parts of him going, such as his head, the fur on his head, and his bottom. 

Here is another example from Disney's The Lion King. Feel free to watch the whole video, but please skip to 0:50 on the Youtube video for the example:

Mufasa's Ghost

What am I looking at?

• As Simba (Lion) stops suddenly, his hair continues to move forward. This is Followthrough. The hair was moving in the same direction as Simba was going, and continued when he stopped.

Overlapping Action: This principle explains that when the main part of an object changes direction, other parts such as clothes keep moving forward [1].

Here is an example from the Loony Tunes series by Warner Brothers:

Bully for Bugs

What am I looking at?

What to watch in this example is the cloth that Bugs Bunny holds up for the bull. As Bugs moves the cloth around, his hands will go down and the cloth will continue to move up. As his hand changes, the cloth takes a while to catch up, and continues to move in the direction it was going. Overlapping Action helps give a softness and flow to an object.

The difference in these two principles is the direction. Followthrough is the continuous movement forward, while Overlapping Action had the main body changing direction and other parts continuing forward.

How can I apply this to my work?

• Followthrough and Overlapping Action are usually applied to soft, flowing, or floppy things (or getting hard things to appear that way). When looking for this principle, look for cloth, hair, and quick movements. Also, you can look for areas of movement and Squash and Stretch together.

• If you want to exaggerate movement, whether it is really fast or a sharp turn, drag your character (or it's limbs, tails, cloth, or hair) so that select parts keep moving forward.

• Attention to detail makes a huge difference to the viewer, so any little thing you can add, such as the cloth of a robe moving on your characters arm, adds character, life, spunk, and is interesting to look at.

Sources

[1] Atkinson, David. Animation Notes #5 Principles of Animation.  Retrieved from http://minyos.its.rmit.edu.au/aim/a_notes/anim_principles.html.