- One guy pins another guy's arm behind his back while a third socks him in the stomach.
- A wounded guy is carried with his arms around the shoulders of two others.
- Caught in an alley, fighting the guy in front, get sapped from behind (or kidney punched).
- Caught by a mob.
- Step between two fighters, push them apart. (Referee?)
They're all great movie moments, but all of these require three or more characters to be closely involved in the action. And that, according to the guys building it, is a real challenge.
Animating one character is tricky enough, when you think of how many different actions you need to combine (walking, talking, breathing, holding something, gesturing, and so on). Animating two characters working together is really hard. You have to make sure they fit together without intersecting or missing. According to one of the guys working on The Sims 3, they spent several years trying to get two characters to walk hand in hand, and they eventually gave up. If you look closely at any game, you'll see people intersecting or air kissing. That usually doesn't matter in a game, where you're focusing on getting through the level or landing that dream job. But in a movie, where the viewer is focused on the characters, it's a big problem.
We have some two-person animations. Not as many as we'd like, admittedly, but enough to have some basic character interaction.
But now we're going to have a go at three person animations. We won't get everything on that list above, and it may take a while, but hey - we'll see what we can do.