2009

Biped Properties

The biped skeleton has some properties designed to help you animate faster

and more accurately.

■ A human structure—Joints on the biped are hinged to follow human

anatomy. By default, the biped resembles a human skeleton and has a

stable inverse kinematics hierarchy. This property means that when you

move a hand or foot, the corresponding elbow or knee orients itself

accordingly, and produces a natural human posture.

■ Customizable for non-human structures—The biped skeleton can easily

be made to work with a four-legged creature or an animal that naturally

leans forward, such as a dinosaur.

■ Natural rotations—When you rotate the biped spine, the arms maintain

their relative angle to the ground, rather than behaving as though fused

to the shoulders. For example, take a biped in a standing position, with

arms hanging at its sides. If you rotate the spine forward, the fingers touch

the ground rather than pointing behind it. This position is more natural

for the hands, which speeds the process of keyframing the biped. This

feature also applies to the biped head. When you rotate the spine forward,

the head maintains a forward-looking orientation.

■ Designed for footsteps—The biped skeleton is specially designed to animate

with character studio footsteps, which help solve the common animation

problem of locking the feet to the ground. Footstep animation also provides

an easy way to rough out animation quickly. See the section

Creating

Footstep Animation

on page 4176.