How to create a realistic army of 50,000 on your computer.

Wired News: Digital Actors in Rings Can Think

The computer-generated characters, called agents, have minds of their own.

"Every agent has its own choices and a complete brain," Regelous said. "The most important thing about making realistic crowds is making realistic individuals."

Like real people, agents' body types, clothing and the weather influence their capabilities. Agents aren't robots, though. Each makes subtle responses to its surroundings with fuzzy logic rather than yes-no, on-off decisions. And every agent has thousands of brain nodes, such as their combat node, which has rules for their level of aggression.

When an animator places agents into a simulation, they're released to do what they will. It's not crowd control but anarchy. That's because each agent makes decisions from its point of view. Still, when properly genetically engineered, the right character will always win the fight.

"It's possible to rig fights, but it hasn't been done," Regelous said. "In the first test fight we had 1,000 silver guys and 1,000 golden guys. We set off the simulation, and in the distance you could see several guys running for the hills."