Massive Attack

摘要

In december vast hordes of eager filmgoers will mob cineplexes across the land and witness, at the climax of The Two Towers, one of the most anticipated scenes in recent movie history: the great Battle of Helm's Deep. The Two Towers is the second film in Peter Jackson's audacious and, so far, triumphant Lord of the Rings trilogy (the films are being released by New Line Cinema, which, like POPULAR SCIENCE, is owned by AOL Time Warner). In this installment, the action takes a darker turn: Humanity and its ragtag allies engage the monstrous forces that would dominate Middle Earth. Humans, hobbits, wizards, dwarves and elves are called to arms against Ores, Ringwraiths and their awful legion of followers―some 50,000 fighters on the ground, all but the relatively small number of main characters computer-generated. The battle rages across the foot of a great mountain range. Lightning flashes and rain pounds the nighttime spectacle. Fighters skirmish up and down the long ladders that line the fortress walls. The battle represents a milestone in computer-generated filmmaking. Combat scenes are one of the big challenges of the digital arts, so complicated is the mix of chaos and purposeful action that plays out when soldiers clash in large numbers. Swell the number to thousands and make each fighter appear autonomous onscreen: That was the gauntlet Jackson threw down to his programmers, and if they have pulled it off this will be the most spectacular CG scene ever. Needless to say, new technology was required. Massive characters, or "agents," function as complex beings subject to physical forces, with specific body attributes that range from the biological (short, good eyesight, dark skin) to the behavioral (aggressive). These features govern a Massive character's ability to generate credible motion. Each character is assigned a host of potential actions, as many as 350, each about a second long (sword up, sword down, step forward, step back). How these actions play out is determined by the character's brain, a tangled web of anywhere from 100 to 8,000 behavioral logic nodes, which provide the rules that allow each character to perceive, interpret and respond to what's happening around it: to make decisions and act. These nodes group into rule collections which control aggression, fighting style, movement across varied terrain, and a dozen other factors. Regelous originally tried to use pen and paper to sketch the relationships between nodes in a character. "It got chaotic very fast," he says, and Massive designers now use a special graphical user interface to connect nodes and create an agent's brain. A fully formed character―a map of its tendencies, its personality, if you will―looks like a huge, multidimensional spider web on the screen.