9

1172 Chapter 14: character studio
See also
Cognitive Controller Editor (page 2–1206)
State Dialog (page 2–1207)
State Transition Dialog (page 2–1208)
Using Motion Synthesis
You can create advanced, complex crowd
simulations in character studio with motion
synthesis, which lets the software adjust the
simulation results dynam ically to account
for differing conditions. Two different forms
of motion synthesis are a vailable: one for
non-bipedal crowds, and a second for the more
exacting requirements of biped cro wds.
See also
Biped Crowds (page 2–1172)
Non-Biped Crowds (page 2–1179)
Biped Crowds
The biped crowd is a special case of crowd
simulation necessitated by t he complex nature
of legged animal movement. Biped locomotion
exhibits intricate dynamics and exacting IK
foot constrain ts. As such, the smoothly curving
trajectories computed from delegate motion
parameters, while suitable for birds, fish, insects,
and snakes, are not rich enough to animate the
microstructure of bipedal m otion. Therefore,
several features in Crowd are focused on the
special needs of bipeds.
In order to generate the required level of nuance,
animated motion clips form the basis for the
repertoire of biped movements. In other words,
during a Biped/Crowd simulation, the delegates
have no effect over the motion of the Biped, they
only set goals to be achieved using clips available
in the Motion Flow graph. With this approach,
known as motion synthesis,theanimatorcan
precisely control details in the mot ion either
by using hand animation or employing motion
capture to produce a set of clips that describe how
a member in the crowd behaves.
For example, if you wanted to animate a crowd
of mar athon runners mak ing their way through
the streets of a city, you would need motion clips
for various k inds of walk ing , r unning, jogging,
resting, drinking water, cheering, etc. In effect,
each of the motions you might expect to see in a
marathon race could be represented as a clip. But
motion must be more than a fragmented collec tion
of clips. You must also consider how motions
might b e sequenced. Which motion transitions
arepossiblefromagivenmotionclip?
To best understand this process, study this topic
and follow the procedure Using bipeds in a crowd
simulation (page 2–1175).
Moti on Flow Net work a nd Pos sibl e
Scripts
Biped’s Motion Flow (page 2–1043) functionality
provides the mechanism for defining how separate
motions fit together into a fluid animation. In
effect, the mot ion flow network describes which
motions can follow from other motions. Once the
motion flow network is defined, a broad set of
animatedactionsispossiblebyfollowingdifferent
paths through the network. In Biped, a path
through the network is called a motion flow scr ipt.
For example, shown below is a motion
flow network used in the sample file
walkers.max. Youcanfindthisfileinthe
cstudio\tutorials\biped_crowds folder in your
3dsMaxpath.ThisfolderalsocontainstheBIP
files used in the motion flow network. You c an
access these f iles only if you have installed tutorials