TimingTiming is the very base of animation, giving an object variations of force (speed, weight etc). Everything we see on TV or in the cinema is set to the pace of the human brain, hence why we see 12fps as flowing movement. The gaps between key positions influence the importance of the movement.
Timing in Disney’s Fantasia is crucial to the whole feature, as it is all timed perfectly to an orchestra. In this piece (03:40) the animators have first marked on screen each key position (as beads of light) and then used the gap between beats to reveal the ‘timeline’ using trailing lines. This is the simplest form of combining timing and motion to show the inner mechanics of fundamental animation
Slow In and Slow OutSometimes a movement can be so fast that it almost doesn’t register with the viewer. By steadily building up to the climax, precognition within the audience can help guess the next action, while a gentle decline afterwards verifies the action through reaction.
Wiley Coyote is well known for running off cliffs, but by watching carefully you will notice that the actual decent out of shot is only a few frames long. Running on thin air gives us a big clue as to what happens next, and the next shot looking down the cliff face reveals his gradual plummet to the ground. Slow build up, fast action and slow reaction.
In essence, arcs are the connecting joints to a base pivoting joint (e.g. fingers through to shoulder). They can be used on any movement made by a flexible substance. Hair is a common example, as its small width allows for optimum curvature, but again, this can be applied to a spine, tail or even plants and trees blowing in the wind. If nothing else, arcs represent the flow of a force pushing/pulling into and around an object.
Feet of Song is a wonderful way of viewing our bodies, and their potential energy becoming kinetic throughout. At some point the joints become invisible, almost as a metaphor for the driving force (e.g. arms) pushing through the air and falling with gravity. This pendulum movement is what creates drag and adds realism to an animation.