Video game fabric simulation scores on realism

? The Super Mario Brothers’ overalls have always been one blocky mass connected to their mushroom-smashing bodies. When “NBA 2K6” is released this fall on Xbox 360, the most striking innovation will be LeBron James’ spiffy threads – not his dunk ability.

Thanks to new cloth simulation technology developed by Visual Concepts, the developers of 2K Games’ popular “2K” sports series, the digital NBA players’ flowing micromesh uniforms will be totally separate from their muscle-bound bods.

Chris Larson, senior software engineer for Visual Concepts, explained this dribble toward reality – and what these avatars have on under their shorts.

Q: In a sports game, why focus on clothing?

A: Sports games chase realism and one of the things that has been missing from all sports games is a lot of secondary animation. The players run around with motion-capture animation that everybody’s using. You can get pretty lifelike motion, but their muscles don’t move. Their hair doesn’t bounce. Their clothes don’t bounce. They look kinda stiff.

Q: So what’s different about this technology?

A: The clothing – instead of being attached to the players – is attached more like regular clothing. In other words, on our shorts, the waistband is attached to the player as it would be in real life and the rest is left kind of flapping in the wind. The waistband responds to the player’s motion and it pulls around the rest of the model.

Q: What else could you do with this clothing?

A: Actually, quite a few things. We’re using this same technology for the basket nets. We actually think it’s got application for things like hair or banners in the crowd. You know, anything that’s made of cloth could be done this way.

Nice drawers, dude. This composite for 2K Sports' NBA

Q: If you wanted to, could you put an NBA player in a gown?

A: We’ve not actually built a dress model, but the method we’ve come up with is very general purpose. We started with the shorts. And then we got those working in the game. Then we put the jersey on. The jersey was a little different and presented some different challenges, but it runs on the same computer code under the hood. I think if we wanted to do a dress, we could do it very easily, but I don’t think the NBA would let us put that in the game. That’s not the image they’re going for.

Q: What are the cheerleaders wearing?

A: Right now what they’re wearing is essentially skin-tight and tiny. Using the cloth simulation isn’t particularly useful because it doesn’t move.

Q: Not all NBA players are the same size. How do you tackle dressing these guys?

A: Just like real life, we’ve built several different sizes of jerseys and several difference sizes of shorts. We’re going to choose the right pair for the right players. Part of the cloth simulation is knowing when it’s colliding with the body. You can’t have the shorts wave through the legs. That’s not very convincing. If somebody has legs that are bigger around, their shorts will collide quicker with those legs.