Originally defined by Frank Thomas and Ollie Johnston in their book “The Illusion of Life: Disney Animation”.
1) Straight-Ahead and Pose-to-Pose- The two main approaches to the creation of movement. Straight-Ahead tends to be rougher and spontaneous, while Pose-to-pose provides a more controlled plan of attack that outlines key actions before in-betweening each frame.
2) Arcs- The visual path of action for natural movement.
3) Ease In and Ease Out- The style or method in which action begins and terminates. The “spacing” of in-between frames to achieve subtlety of transitions & movements. Hard or soft accents can be used to alter the feel of the action.
4) Timing- Adjusting the length of time between actions or key poses to define the weight, size, and personality of objects and characters.
5) Squash and Stretch- Defining the rigidity and mass of an object by distorting its shape during an action.
6) Overlapping Action or Secondary Action - Establishing how one action relates to the next. This practice is used to maintain flexibility in characters by “breaking the joints” and by calculated adjustments to the addition or lack of “twinning” with a character’s limbs.
7) Anticipation- The preparation for an action. This movement is often in the opposite direction to the key pose or movement.
8) Line of action- The movement of energy through a character as defined by a single line arcing through the character’s body down to a primary point of balance. Adjusting the line of action over time can help an animator achieve smooth motions or abrupt changes in weight and force.
9) Drag and Follow Through- The Action of an object resulting from another action. Examples of this would be hair, clothing, a tool hanging from a belt, etc. Generally refers to animated objects which have no inherent control or power of their own.
10) Character Nuance - Supplemental movement (of limbs) to add texture and personality to the primary action (of body)
11) Exaggeration- Accentuating the essence of an idea via the design & the action
12) Staging- Presenting an idea so that it is unmistakably clear. This is primarily achieved through the practice of effective camera placement, composition of frame, and character silhouettes.
13) Appeal- Anything that a person likes to see: a quality of charm, pleasing design, simplicity, communication and magnetism.
