PHYSICAL: the 12 principles of AnimationThe Illusion of Life: Disney Animation, Frank and Ollie Johnston

Squash and stretch

The most important principle is "squash and stretch",the purpose of which is to give a sense ofweight and flexibility to drawn objects. It can be applied to simple objects, like a bouncing ball,or more complex constructions, like the musculature of a human faceTaken to an extreme point,a figure stretched or squashed to an exaggerated degree can have a comical effect. In realisticanimation, however, the most important aspect of this principle is the fact that an object'svolume does not change when squashed or stretched. If the length of a ball is stretchedvertically, its width (in three dimensions, also its depth) needs to contract correspondinglyhorizontally.

Illustration of the "squash and stretch"-principle:Example A shows a ball bouncing with a rigid, non-dynamic movement. In example B the ball is"squashed" at impact, and "stretched" during fall and rebound. The movement also accelerates during thefall, and slows down towards the apex (see "slow in and slow out").

Anticipation

Anticipation is used to prepare the audience for an action, and to make the action appear morerealistic. A dancer jumping off the floor has to bend his knees first; a golfer making a swing hasto swing the club back first. The technique can also be used for less physical actions, such as acharacter looking off-screen to anticipate someone's arrival, or attention focusing on an objectthat a character is about to pick up.

Anticipation: A baseball player making a pitch prepares for the action by moving his arm back.

For special effect, anticipation can also be omitted in cases where it is expected. The resulting sense of

anticlimax will produce a feeling of surprise in the viewer, and can often add comedy to a scene. This is

often referred to as a 'surprise gag'.

Staging

This principle is akin to staging as it is known in theatre and film. Its purpose is to direct theaudience's attention, and make it clear what is of greatest importance in a scene; what ishappening, and what is about to happen. Johnston and Thomas defined it as "the presentationof any idea so that it is completely and unmistakeably clear", whether that idea is an action, apersonality, an expression or a mood.The essence of this principle is keeping focus on what isrelevant, and avoiding unnecessary detail.

Straight ahead action and pose to pose

These are two different approaches to the actual drawing process. "Straight ahead action"means drawing out a scene frame by frame from beginning to end, while "pose to pose"involves starting with drawing a few, key frames, and then filling in the intervals later. "Straightahead action" creates a more fluid, dynamic illusion of movement, and is better for producingrealistic action sequences. On the other hand, it is hard to maintain proportions, and to createexact, convincing poses along the way. "Pose to pose" works better for dramatic or emotionalscenes, where composition and relation to the surroundings are of greater importance. Acombination of the two techniques is often used.

Computer animation removes the problems of proportion related to "straight ahead action"drawing; however, "pose to pose" is still used for computer animation, because of theadvantages it brings in composition. The use of computers facilitates this method, as computerscan fill in the missing sequences in between poses automatically. It is, however, still important to

oversee this process, and apply the other principles discussed.

Follow through and overlapping action

These closely related techniques help render movement more realistic, and give the impressionthat characters follow the laws of physics. "Follow through" means that separate parts of a bodywill continue moving after the character has stopped. "Overlapping action" is when a characterchanges direction, and parts of the body continue in the direction he was previously going. Athird technique is "drag", where a character starts to move and parts of him take a few frames tocatch up. These parts can be inanimate objects like clothing or the antenna on a car, or parts ofthe body, such as arms or hair. On the human body, the torso is the core, with arms, legs, headand hair appendices that normally follow the torso's movement. Body parts with much tissue,such as large stomachs and breasts, or the loose skin on a dog, are more prone to independentmovement than bonier body parts. Again, exaggerated use of the technique can produce acomical effect, while more realistic animation must time the actions exactly, to produce aconvincing result.

Thomas and Johnston also developed the principle of the "moving hold". A character not inmovement can be rendered absolutely still; this is often done, particularly to draw attention tothe main action However, this gave a dull and lifeless result, and should be avoided. Evencharacters sitting still can display some sort of movement, such as the torso moving in and outwith breathing.

Slow in and slow out

The movement of the human body, and most other objects, needs time to accelerate and slowdown. For this reason, an animation looks more realistic if it has more frames near thebeginning and end of a movement, and fewer in the middle. This principle goes for charactersmoving between two extreme poses, such as sitting down and standing up, but also forinanimate, moving objects, like the bouncing ball in the above illustration.

Arcs

Most human and animal actions occur along an arched trajectory, and animation shouldreproduce these movements for greater realism. This can apply to a limb moving by rotating a

joint, or a thrown object moving along a parabolic trajectory. The exception is mechanicalmovement, which typically moves in straight lines.

Secondary action

Adding secondary actions to the main action gives a scene more life, and can help to supportthe main action. A person walking can simultaneously swing his arms or keep them in hispockets, he can speak or whistle, or he can express emotions through facial expressions. Theimportant thing about secondary actions is that they emphasize, rather than take attention awayfrom the main action. If the latter is the case, those actions are better left out. In the case offacial expressions, during a dramatic movement these will often go unnoticed. In these cases itis better to include them at the beginning and the

end of the movement, rather than during.

Secondary action: as the horse runs, its mane and tail follow the movement of the body.

Timing

Timing in reality refers to two different concepts: physical timing and theatrical timing. It isessential both to the physical realism, as well as to the storytelling of the animation, that thetiming is right. On a purely physical level, correct timing makes objects appear to abide to thelaws of physics; for instance, an object's weight decides how it reacts to an impetus, like a push.Theatrical timing is of a less technical nature, and is developed mostly through experience. Itcan be pure comic timing, or it can be used to convey deep emotions. It can also be a device to

communicate aspects of a character's personality.

Exaggeration

Exaggeration is an effect especially useful for animation, as perfect imitation of reality can lookstatic and dull in cartoons. The level of exaggeration depends on whether one seeks realism orcomedy. The classical definition of exaggeration, employed by Disney, was to remain true toreality, just presenting it in a wilder, more extreme form. Other forms of exaggeration caninvolve the supernatural or surreal, alterations in the physical features of a character, orelements in the storyline itself. It is important to employ a certain level of restraint when usingexaggeration; if a scene contains several elements, there should be a balance in how thoseelements are exaggerated in relation to each other, to avoid confusing or overawing the viewer.

Anime figures are characterised by exaggerated facial features, in particular the large eyes.

Solid drawing

The principle of solid — or good — drawing, really means that the same principles apply to ananimator as to an academic artist. The drawer has to understand the basics of anatomy,composition, weight, balance, light and shadow etc. For the classical animator, this involvedtaking art classes and doing sketches from life. One thing in particular that Johnston andThomas warned against was creating "twins": characters whose left and right sides mirrored

each other, and looked lifeless. Modern-day computer animators in theory do not need to drawat all, yet their work can still benefit greatly from a basic understanding of these principles.

AppealAppeal in a cartoon character corresponds to what would be called charisma in an actor. A

character who is appealing is not necessarily sympathetic — villains or monsters can also be

appealing — the important thing is that the viewer feels the character is real and interesting.

There are several tricks for making a character connect better with the audience, for likable

characters a symmetrical or particularly baby-like face tends to be effective.

EMOTIONAL:

12 QUESTIONS_by Frank Thomas & Ollie Johnston, June 2003

1. Is the character doing what the director wants in the sequence?

2. Is the character doing only one thing at a time?

3. Is the character putting over the story point in the scene you are doing?

4. Is the character acting as if there is something going on in his mind?

5. Does the character appear to be doing something on his own?

6. Can the audience tell what the character is thinking?

7. How does what the character is doing effect what the audience is thinking?

8. Does the character have appeal?

9. Is it passionate? Is passion going into the drawing and coming out of the character?

10. Is it the simplest way to do it?

11. Have you made small story sketches of one important character to be sure everything is

working before you make a lot of drawings?

12. Would any one else besides your mother like what you have done?

NOTES and Tips

1 .Donʼt illustrate words or mechanical movements. Illustrate ideas or thoughts, with theattitudes and actions._

2 Squash and stretch entire body for attitudes.

3 If possible, make definite changes from one attitude to another in timing andexpression._

4 What is the character thinking?

5 It is the thought and circumstances behind the action that will make the actioninteresting.__Example: A man walks up to a mailbox, drops in his letter and walksaway.__OR__A man desperately in love with a girl far away carefully mails a letter inwhich he has poured his heart out.

6 When drawing dialogue, go for phrasing. (Simplify the dialogue into pictures of thedominating vowel and consonant sounds, especially in fast dialogue.

7 Lift the body attitude 4 frames before dialogue modulation (but use identical timing onmouth as on X sheet).

8 Change of expression and major dialogue sounds are a point of interest. Do them, if atall possible, within a pose. If the head moves too much you wonʼt see the changes.

9 Donʼt move anything unless itʼs for a purpose.

10 Concentrate on drawing clear, not clean.

11 Donʼt be careless.

12 Everything has a function. Donʼt draw without knowing why.

13 Let the body attitude echo the facial.

14 Get the best picture in your drawing by thumbnails and exploring all avenues.

15 Analyze a character in a specific pose for the best areas to show stretch and squash.Keep these areas simple.

16 Picture in your head what it is youʼre drawing.

17 Think in terms of drawing the whole character, not just the head or eyes, etc. Keep abalanced relation of one part of the drawing to the other.

18 Stage for most effective drawing.

19 Draw a profile of the drawing youʼre working on every once in a while. A profile is easieron which to show the proper proportions of the face.

20 Usually the break in the eyebrow relates to the highpoint of the eye.

21 The eye is pulled by the eyebrow muscles.

22 Get a plastic quality in face — cheeks, mouth and eyes.

23 Attain a flow thru the body rhythm in your drawing.

24 Simple animated shapes.

25 The audience has a difficult time reading the first 6-8 frames in a scene.

26 Does the added action in a scene contribute to the main idea in that scene? Will it helpsell it or confuse it?

27 Donʼt animate for the sake of animation but think what the character is thinking and whatthe scene needs to fit into the sequence.

28 Actions can be eliminated and staging "cheated" if it simplifies the picture you are tryingto show and is not disturbing to the audience.

29 Spend half your time planning your scene and the other half animating.

Ex: How to animate a scene of a four-legged character acting and walking: Work out theacting patterns first with the stretch and squash in the body, neck and head; then go back inand animate the legs. Finally, adjust the up and down motion on the body according to thelegs.