2009

■ Mixdowns allow for precise elimination of the foot sliding with the aid of
knee limit filtering to unnatural knee poppimg artifacts. In short, the goal
of the mixer is to assemble seamless, coherent character motion using
building blocks composed from other motion fragments.
For non-biped rigs and other 3ds Max objects, the Mixer provides velocity
blends and sub-blends to maintain smooth and coordinated motion.
Comparing the Motion Mixer and Motion Flow
Both the Motion Mixer and
Motion Flow on page 4508 can be used to create
transitions between a consecutive series of BIP files. However, there are a few
significant differences between the two features:
■ With the Motion Mixer, several BIP files can be used at the same time to
affect biped motion. Compare with Motion Flow, where only one BIP file,
or a transition between two consecutive BIP files, affects the biped at any
given time.
■ With the Motion Mixer, you can specify that a BIP file will affect only one
part of the body. This feature is not available in Motion Flow.
■ In the Motion Mixer, you can use a mixdown to automatically lock feet
during transitions between biped foot-based motions. Motion Flow does
not perform this function.
■ A Motion Flow network can be used in conjunction with the Crowd feature,
giving the bipeds a choice of motions over the course of the simulation.
The Motion Mixer does not generate motion for biped crowds.
■ A Motion Flow network can be used to randomly generate different motion
scripts for one or more bipeds. This feature is not available in the Motion
Mixer.
Use the Motion Mixer when you want to create a specific animation for an
object from several clips, or you want to specify that some motions be applied
only to specific body parts. If you want to work with biped crowds or create
random motion, use Motion Flow.
If you're creating a straight series of transitions between motions, you can use
either one. However, the Motion Mixer has additional tools for improving
foot-based transitions.
3702 | Chapter 15 Animation