One Coordinate System
The Interactive Web of Virtual Life and Avatars

JJ Ventrella
Second Co-founder and
Principle Inventor of There, Inc.

(below is an abstract for a presentation at Universidad del Pais Vasco, Bilbao Spain, 2005)


Much of our work at There, Inc. has been focused on building a dynamic web of life in the Metaverse, primarily among avatars, but also including animals. All of these entities react to each other autonomously, and maintain "mental" states regarding each other. Behaviors include focused gaze, collective locomotion, directed body language, and touch. In the case of avatars, the primary behaviors are guided by users, however they do exhibit involuntary behaviors.

When building artificial life simulations with hundreds of physics-based creatures, I design interaction and stimulus-response behavior into the very fabric of the simulations. Compare this to the standard way of building 3D models. Most modeling and animation systems use a local coordinate system for each individual object. It requires an extra level of technology to allow these entities to interact in a meaningful way. It is as if animated 3D models are anti-social by nature.

Looking at or touching another person is a natural and thoughtless act. The same goes with fishes mating, and cats chasing mice. Emergent phenomena, both in the case of artificial life behaviors, as well as in the formation of avatar-based communities, all require significant and continual interaction among the entities - nothing can emerge if they just live in their own local coordinate systems.

In this presentation, I describe techniques for representing virtual animals and humans in which all entites share a common space of physical, biological, and social interactions. This is accomplished through techniques such as AI, procedural animation, inverse-kinematics, forward dynamics, and approximating vision and audition. I will demonstrate many examples of virtual life forms - including simple shapes that chase each other around, spring-based walking figures that respond to uer manipulation, and virtual dogs that can hear and respond to avatar chat commands.