9

Biped 843
Use Cr owds to Ani mate G roups of
Characters
Once you’ve created animation sequences for
characters or other models (such as a bird flapping
its wings), you can replicate the models or
characters and apply the motions to these groups
using the Crowd system (page 2–1154).Youcan
alsocombinethemwithawiderangeofsupplied
behaviorstocreatelifelikeactivitiesincrowds,
such as people st reaming through a door way, street
traffic, or birds and fish flocking and avoiding
obstacles. You can use Motion Flow m o de to create
motion clip networks so that characters perform
animation sequences appropriate to their current
movement and transition smoothly between
sequences. And you can use Crowd’s cognitive
controllers to transition between b ehaviors based
on a variety of criteria. For more on crowd
behaviors, see Creating a Crowd S ystem (page
2–1155).
Biped
To work most efficiently with bipeds, it is
important to follow the general workflow
described in this topic.
Create Sk in Geometry
Before you create a skeleton for a character, you
should already have a character skin to put the
skeleton into.
Create a basic skin shape for your character using
any of the 3ds Max modeling tools and surface
types. Be sure to place your character’s skin in
a neutral pose w ith arms outstretched and legs
spaced slightly apart. You may also want to add
sufficient detail to your skin’s mesh or control
points around joints to facilitate deforma tion
during movement.
Character mesh in a neutral p ose
Tip: Before adding a biped skeleton, freeze your
character mesh. When the mesh is frozen, you can
still see it, but you can’t select or alter it, reducing
thechanceforerrororfrustration.
Create a B i ped Skeleton
Once you have a character mesh, you can create a
biped skeleton to fit inside. Use Figure mode (page
2–982) to set up your biped.
Before you position the skeleton, use controls on
the Structure rollout (page 2–984) to alter the biped
to match your mesh, setting the number of links
for the spine, ar ms, neck, or fingers, or adding
propstorepresentweaponsortools.
Tip: You can use ponytai ls to create animated jaws,
ears, or horns.
Note: Certain biped body parts, including fingers,
tails, ponytails, props, and clavicles, can be
repositioned in Figure mode to suit different
characters.
When you position the biped inside your mesh,
star t with the center of mass (COM), which is the
parent of all objects in the biped hierarchy. The
COMshouldbepositionedinlinewiththehips
of the mesh character. Scale the pelvi s s o that the
legs fit properly in the mesh, and then use Move
and Scale on the 3ds Max toolbar to position your
biped skeleton.