Introduction to animation

Conventional animation principles:

anticipation, action, follow-through
squash-stretch
timing
- Speed conveys mass and personality
- Traditional animators would draw a timechart with a time scale to indicate the generation of in-betweens

Keyframe: position defining the start and end points of any smooth transition

Computer-assisted animation:

Position interpolation

Given $t \in [t_i, t_{i+1})$,

\[x(t) = x(t_i) \frac{t_{i+1} - t}{t_{i+1} - t_i} + x(t_{i+1}) \frac{t - t_i}{t_{i+1} - t_i}\]

Interpolation can happen on rotation angle and/or position.