Graphics Reference
In-Depth Information
FIG 3.6
The arms may assist a
figure in locomotion but they are
not vital to the action. As such, they
demonstrate secondary action.
locomotion by creating balance or efficiency in movement, they do not
drive
the movement.
These secondary actions may often make for more effective, efficient, and
economic movement in the figure as whole, but it may still be possible for the
figure to move without the use of these secondary actions.
Secondary actions occur in all manner of movements. Although they might
not be the focus of an animated movement, they will often provide the
necessary element to make the animation appear believable. If they are
omitted from an animated action, the results are at best rather ordinary and at
worst lack naturalistic and convincing movement.
The action of the arms during a walk makes a contribution to the overall
movement, providing a twist to the upper torso and a countermovement to
the legs. However, the animation of the arms isn't critical or even necessary
for that particular movement to be made. Although it might look a little
unusual or even completely unnatural, it is perfectly feasible for a figure to
walk without swinging its arms. The action of the arms during a run is more
dynamic and more pronounced than in a walk; the role the arms play in
assisting the overall dynamic of a run may be far greater than in a walk. Once
again, it is still possible, if a little more awkward, for a running figure to keep
its arms motionless and hanging by the side of the body throughout the
action.
Tertiary Action
Finally, let's look at tertiary action. This action, like secondary action, is a result
of movement brought about by primary action. Tertiary actions are those
that are a result of the main movement or secondary actions and do not
themselves assist or necessarily contribute to the effectiveness of the overall
movement. In addition to being instigated by primary action, tertiary action
