Digital illumination takes massive computing power
Lights, camera, action. That works for live action and stop-motion animation, which use physical lights. But in CG animation, that goes backward: action, camera, lights. “We retrofit lighting into the scenarios,” says David James, production director for DreamWorks’ CG animated feature “Monsters vs. Aliens.”
They have to. “Lighting a shot requires so much computing power, and it takes so long to get one frame, it’s not practical to have fully lit scenes for the animators,” James explains.
Although art directors and d.p.s choreograph the lighting design early in the process by painting key scenes, final lighting must wait for the stage to be set with the characters in their costumes.
“It isn’t about how the light shines on the characters and objects, it’s how it bounces off that makes or breaks the look of a shot,” James notes. And that depends on how technical directors define the surfaces, whether they are furry or fleshy, leather or wood, dry or wet, shiny or, in the case of “Monsters'” Bob, translucent with environments refracting inside his blobby body.
Once the stage is set and the digital characters are in place, CG lighters tend to work like live-action cinematographers. That was especially true for Robert Presley, director of photography on “Disney’s A Christmas Carol.” ”(Director Robert Zemeckis) and I come from a live-action background, so we treated lighting much like a live-action movie,” Presley says. “But the bonus is that we could do things that we couldn’t do on a live-action set, like move shadows without moving lights.”
For “9,” d.p. Kevin Adams pushed the possibilities even further: “We’d start with the same lights as live action. But, we were doing this in a painterly way.”
That ability to control the CG look precisely has a downside. “There are no happy accidents,” Presley says. “It isn’t like the sun shoots through the window and bounces on the floor. You have to make every single pixel on the screen look the way it looks. But there are no limitations. It’s a very freeing experience.”