Full story.Taken from wired.com article:
In Massive, agents' brains -- which look like intricate flow charts -- define how they see and hear, how fast they run and how slowly they die. For the films, stunt actors' movements were recorded in the studio to enable the agents to wield weapons realistically, duck to avoid a sword, charge an enemy and fall off tower walls flailing.
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.