2009

Non-Biped Crowds
Motion synthesis in character studio lets the software derive character motion
from a combination of crowd behaviors and either motion flow networks,
when animating bipeds (see Biped Crowds on page 4793), or clip controllers,
when working with non-bipedal creatures. In the latter case, using the Global
Motion Clip and Master Motion Clip controllers, you can animate groups of
creatures such as birds, butterflies, schools of fish, and insects. You can create
clip controllers either as block controllers in Track View, or, more directly,
with the Crowd helper controls on the Global Clip Controllers rollout.
Two Approaches to Animation
You can animate your creature either in place with looping animation but no
transformational motion (such as a bird flapping its wings), or you can
incorporate transformational motion into the animation as well (the bird
moves upward while flapping its wings). In-place cyclic motion lends itself to
flying or swimming motions like birds and fish, while adding lateral motion
lends itself to crawling type animation where feet should be planted on the
ground and not sliding. Depending on which you use, you toggle options on
the Motion Clips tab of the Synthesis dialog. In both cases, you use crowd
delegates driven by behaviors to motivate the creatures, which are linked to
those delegates.
NOTE To animate a model for motion synthesis, apply modifiers to the model
and animate their parameters. Modifiers such as Bend, Taper, Wave, and Xform
produce animation you can use with motion synthesis. Do not use sub-object
animation, such as animation of vertices on an Editable Mesh object.
Cyclic In-Place Animation
First you create a creature with a few short loop cycles, like the beating of
wings, gliding, turning left and turning right. This creature is assigned as the
Global Object or the master object from which the motion clips will be derived.
Then clones of the original creature are created. The clones are positioned and
linked to delegates. States are created to select which clips will play based on
a state.
For example, if a bird (delegate) is pitching up or accelerating, the fast-beating
clip is used; if the bird (delegate) slows to a stop, the wings-at-rest clip is used,
and so on. During synthesis, the software determines which state should be
active depending on the speed and direction of the delegates. An active state
determines which clip should be applied to the clones of the original object.
Using Motion Synthesis | 4805