Animation Basics

In 1981, two Disney animators, Ollie Johnston and Frank Thomas published The Illusion of Life: Disney Animation.  In it they identified Twelve Basic Principles of Animation. These principles help create illusion of characters adhering to the basic laws of physics, and showing emotions.

The Principles:

1) Squash and Stretch – Squash and stretch is the extending and compressing of a character’s body to create the illusion of weight and volume. In this scene, squash and stretch is used to establish how two of Brendan’s mentors, Brother Tang and Brother Assoua, are different not only in height but also in the way their bodies move to form expressions.

2) Anticipation – Animators use anticipation to prep the audience for a forthcoming action. In this scene, Brendan pulls the quill back in anticipation before touching it to the book to make the line.

3) Staging –  This is the concept that every pose or action that a character takes should clearly communicate a character’s goals, attitude, mood, or reaction. Compare these images of Brendan from different scenes. Notice how each pose is different from the other and expresses a clear emotion. If you were to make a silhouette of the character’s pose, you would still be able to tell that these are distinct poses.

4) Straight Ahead & Pose-to-Pose – More related to process than product, this principle highlights the two major methods of animation production: straight ahead and pose-to-pose. Straight ahead animation is popular in stop-motion animation. In this process, the animator will animate one frame at a time in chronological order. Pose-to-Pose involves creating key poses and then adding the in-between “filler” later.

Pose-to-Pose: To animate this scene from The Secret of Kells, animators first developed these key poses for Brendan and his mentor, Brother Aidan and then passed the scene on to other animation studios in Brussels, Belgium, Brazil, and Hungary to fill in the action between these poses.

5) Follow through, and Overlapping Action – Follow through is the concept that when a character stops running or performing an action, their body parts stop moving different times. This one is kinda difficult to see, but if you look closely you’ll notice how when the magical forest fairy Aisling jumps, her body stops on a rock but her hair continues to move a couple frames after.

Tied to the concept of follow through is overlapping action. This concept posits that when the body is in motion, certain parts will inevitably move faster than others. In this scene, take note of how the philosopher Colum-Cille’s arm holding the cane moves at a faster rate than the rest of his body.

6) Slow-In and Slow-Out – The movement of the human body, and most other objects, needs time to accelerate and slow down. For this reason, animation looks more realistic if it has more drawings near the beginning and end of an action, emphasizing the extreme poses, and fewer in the middle. The more frames of an action there are, the slower the action will seem. The less frames of an action there are, the faster the action will seem. This principle goes for characters moving between two extreme poses, such as sitting down and standing up, but also for inanimate, moving objects, like a bouncing ball. When animating an action scene, animators will add more drawings to the beginning parts of the action, less towards the middle, and more again towards the end, creating the effect of a slow-in and a slow-out.

7) Arcs – Almost all of life’s actions have a slightly circular flow to them. Thus animators will often animate actions with an arc trajectory. Sometimes this principle can be exaggerated to add appeal to a character. Most natural action tends to follow an arched trajectory, and animation should adhere to this principle by following implied "arcs" for greater realism. This technique can be applied to a moving limb by rotating a joint, or a thrown object moving along a parabolic trajectory. The exception is mechanical movement, which typically moves in straight lines.

As an object's speed or momentum increases, arcs tend to flatten out in moving ahead and broaden in turns. In baseball, a fastball would tend to move in a straighter line than other pitches; while a figure skater moving at top speed would be unable to turn as sharply as a slower skater, and would need to cover more ground to complete the turn.

An object in motion that moves out of its natural arc for no apparent reason will appear erratic rather than fluid. For example, when animating a pointing finger, the animator should be certain that in all drawings in between the two extreme poses, the fingertip follows a logical arc from one extreme to the next. Traditional animators tend to draw the arc in lightly on the paper for reference, to be erased later.

8) Secondary Action – Adding secondary actions to the main action gives a scene more life, and can help to support the main action. This is an additional action helps to supplement the main action of a scene. A person walking can simultaneously swing their arms or keep them in their pockets, speak or whistle, or express emotions through facial expressions. The important thing about secondary actions is that they emphasize, rather than take attention away from the main action. If the latter is the case, those actions are better left out. For example, during a dramatic movement, facial expressions will often go unnoticed. In these cases it is better to include them at the beginning and the end of the movement, rather than during.

9) Timing – Timing refers to the number of drawings or frames for a given action, which translates to the speed of the action on film.By incorporating more or fewer drawings into the range of an action, an animator is able to mimic the laws of physics to create either slow and smooth movements or fast and crisp movements.  On a purely physical level, correct timing makes objects appear to obey the laws of physics; for instance, an object's weight determines how it reacts to an impetus, like a push. Timing is critical for establishing a character's mood, emotion, and reaction.  It can also be a device to communicate aspects of a character's personality.

10) Exaggeration – Exaggeration involves broadening your character’s facial features, poses, and expressions to add greater understanding to their movements. Exaggeration is an effect especially useful for animation, as animated motions that strive for a perfect imitation of reality can look static and dull. The level of exaggeration depends on whether one seeks realism or a particular style, like a caricature or the style of a specific artist. The classical definition of exaggeration, employed by Disney, was to remain true to reality, just presenting it in a wilder, more extreme form. Other forms of exaggeration can involve the supernatural or surreal, alterations in the physical features of a character; or elements in the storyline itself. It is important to employ a certain level of restraint when using exaggeration. If a scene contains several elements, there should be a balance in how those elements are exaggerated in relation to each other, to avoid confusing or overawing the viewer.

11) Solid Drawings – This principle posits that the basic ideas related to traditional drawing should also be applied to the animation space. Taking into account forms in three-dimensional space, or giving them volume and weight. The animator needs to be a skilled artist and has to understand the basics of three-dimensional shapes, anatomy, weight, balance, light and shadow, etc. For the classical animator, this involved taking art classes and doing sketches from life. One thing in particular that Johnston and Thomas warned against was creating "twins": characters whose left and right sides mirrored each other, and looked lifeless. Modern-day computer animators draw less because of the facilities computers give them, yet their work benefits greatly from a basic understanding of animation principles, and their additions to basic computer animation.

12) Appeal – This concept is hard to pinpoint but easy to identify. Simply put, appeal relates to the idea that images should be able to craft a connection with their audiences. Appeal 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. A complicated or hard to read face will lack appeal, it may more accurately be described as 'captivation' in the composition of the pose, or the character design..

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