By Mary Ann Skweres
Buzz can begin very early. The buzz on Robots began two and a half years before the film’s March 11, 2005, release date. One explanation for this long lead-time is that the animated feature is not only entirely CGI but also uses “radiosity” light-refraction technology from Fox-owned Blue Sky Studios, the animation house in White Plains, New York, known for its pioneering work in CGI character animation and lighting technology on Ice Age and other projects. The studio’s Academy Award winning animation talent is personified by Chris Wedge, director of the Oscar-winning animated short Bunny.
At Blue Sky, according to Carl Ludwig, VP of research and development, “the esthetics inform the technology.” In other words, story and character are the most important elements of a film; the rest is for emotional support to draw the audience into the movie.
Radiosity helps create CG animation that is not only photorealistic but achieves accurate lighting that gives a 3D feel. Based on the concept of ray-tracing, radiosity stimulates the way light interacts with surfaces in the real world—in a geometrically based bounce.
According to Ludwig, this is only part of the process, “We talk not specifically in terms of radiosity, but global illumination”—a concept that takes into account not only radiosity but also distributed light sources such as the sky and other large areas of light that might come into the scene and contribute to the overall lighting scheme.
Because it’s important that lighting design compliment the director’s creative vision, Blue Sky works to find lighting solutions comparable to those a live-action director might employ. The studio achieves much the same soft bounce light with its lighting technology that screens and reflectors on a live-action set would get. “When you have these large light sources and radiant bouncing, they give it that three-dimensional feel, that sense of depth that you don’t get with simple light sources,” explains Ludwig.
Blue Sky is constantly trying to get surface lighting just right. In deciding the lighting of a shot, lighters have to ask questions like: What time of day is it? Where is the light coming from? What’s the nature and distribution of the light? Does a light source need to be added or is it sufficient to let it bounce off something? “It’s always about control,” says Ludwig. “A straight radiosity solution just gives you what you’re going to get. If [the director] wants to modify it or change the angle differently from what the geometry would dictate, it’s a lot easier to do with these screens, these diffuse light sources.”
All this creative flexibility is computer-intensive—everything is completely ray-traced. But Ludwig is less interested in how long it takes to compute and more interested in how much time he can save the person trying to execute the job. “If the tools are powerful enough that a person can achieve a solution quickly and the director is happy with it, we’re way ahead,” he says. “One hour of a person’s time is worth 10 hours of a computer’s time.”
Says Ludwig, “Robots almost looks like—and Chris Wedge wanted this—it was filmed in some fantasy world. We’ve tried to create that illusion. When you look at it you’re not aware of what created the image. It looks real. You know it’s not real but it has this quality of looking real. Robots has this incredibility rich quality to it. We pushed this to its limit.”
