|ONLINE AND KICKING JANUARY 10, 2000
by Ben de Leeuw
Motion Factory announced the 2.0 version of their behavior-driven
animation package Motivate, which will be shipping in March 2000.
With the new version, Motivate is being positioned as a tool for
web 3D development. Though a bit circumspect about the dates,
Motion Factory CEO David Pritchard said a full-featured plug-in
for Navigator and Explorer 4.x on both Windows and Mac was on
its way. The lightweight browser plug-in will give users access
to any content created with Motivate. The biggest limiting factor,
according to Pritchard, will be the pipeline into the user's computer.
Motivate is one of a new breed of web 3D engines that focus on
behavior-driven characters and environments. Motivate allows deep
interactivity because it does not rely on long, canned pieces
of animation, but rather constructs the animation on the fly based
on user input. Characters have multiple behaviors or skills that
can be combined in any order. For instance, the user can direct
the character to pick up something on the other side of a room,
and the character will combine walking, grabbing, and obstacle
avoidance behaviors to navigate across the room and grab the object.
Behavior engines like this, based on a hierarchical finite state
machine, have surfaced in many video games recently, notably Prince of Persia created with Motivate 1.x. With the 2.0 release, Motion Factory
has created the architecture to bring all that functionality to
web 3D. Along with their own player solution, Motivate will be
available as components, allowing developers to combine pieces
of Motivate's technology with proprietary or third-party components.
Facts & Features
Motivate 2.0 includes a motion engine, developed by graduates
of the Stanford robotics lab, that allows characters to learn
motion and locomotion skills and combine them to intelligently
navigate any environment. Other features include a behavior engine,
designed for the hierarchical finite state machines used in real-time
processes, that allows the developer to imbue characters with
goals to govern how they interact with the environment and other
characters; scripting in either Piccolo (Motion Factory's scripting
that allows only the bone transforms to be streamed, with model
deformation accomplished on the client machine; and fully articulated
body dynamics, allowing characters to not only collide with other
objects but to react to those collisions with full skeletal articulation.
For instance, a character punched in the stomach would not have
a canned stomach hit animation but would react to the punch based
on the force, point of impact, and the IK constraints of the skeleton.
Motion Factory's approach is specifically geared towards interactive
behaviors and environments. This is reflected in what their player
will and won't do. While streaming is the watchword for the new
web millennium (which should last through about 2002), Motion
Factory takes a slightly different tack on this subject. They
are prepared to stream geometry, textures, behaviors, and scripts
in discreet chunks, but do not have a continuous data stream for
things like sound and video. Worlds and characters will appear
quickly to the user and stream in additional geometry and behaviors
while you play. A character might initially download with just
a walk and an idle behavior, so the user can immediately begin
exploring the environment. As the user explores, the character
continues to download behaviors behind the scenes, adding more
and more skills. Concurrently the world streams in geometry and
textures becoming larger and richer. For the moment, however,
a character will not be able to stream in long pieces of dialogue.
Small pieces can be streamed in with chunks of data, and strung
together as behaviors, allowing sound effects or minimal character
dialogue, but that long Shakespearean monologue is right out for
As with any unreleased product, the proof will be in the pudding,
but Motivate promises to help open up some new territory in the
world of web 3D.
Ben de Leeuw is creative director at infoplasm (www.infoplasm.com), a San Francisco-based animation studio. He teaches at several
Bay Area animation colleges and is the author of Digital Cinematography (Morgan Kaufmann, 1997).