"Bunny" by Chris Wedge represents a milestone in computer graphics: Radiosity, a highly developed rendering software is used for the first time in a computer animation to simulate natural light in a unique way, which give the animation a filmic "look" never attained before.

"It's a suspense story. A case of mistaken identity, with a twist that I think has a lot of heart to do it," says Chris Wedge. When asked why a rabbit? Wedge answered, "I was always doodling rabbits, I think because I was fascinated by the character of Uncle Wiggly and the animation in those old illustrations from the 1930's. That was definitely an influence.

I wanted to create something in that rich storybook style-realistic, yet fantasy." In fact, the short, which began as an effort to stretch the limits of Blue Sky Studios' proprietary lighting software, has such a warm, filmic, photorealistic style that it belies the computer technology that made it possible. Through the use of a software technique called radiosity, which is a complete simu lation of how natural light works, Wedge and his crew were able to create an unparalleled dimensio nality and organic realism never before attempted in a computer-animated film.

"In a real environment there is usually more than one single color of light illuminating a scene," Wedge explained. "There are all these sympathetic hues-yellow bouncing off a yellow wall, greens being reflected from trees outside, blue from the sky; colours we may not even be aware of unless they're missing. Recreating that ambient illumination in the computer gives us a richness of live action photo graphy and the versability to make anything happen."

Still, pioneering this new technique wasn't easy. The technical team began by setting up a master light ing program that would be fairly consistent through out the film. "That got us 90 percent of the way there," explained Dave Walvoord, who served as digital effects supervisor of the film. "But the real trick came when you'd be looking at a shot and think-oh man! the stove is just popping out way too much and we really want the attention on Bunny. That's when radiosity stopped being our friend and started working against us."

Walvoord said the team couldn't tweak the lightning to correct the brightness of the stove because with radiosity, that little change affected the whole global lighting structure. Ironically, this problem is exactly what happens on a live-action set. "In the studios, they're always fighting radiosity," Walvoord said, smil ing, "But they can stick out their hands and figure out where the shadow is coming from. It's a little more complicated in the computer." The team ended up putting the computer-equivalent of "bounce cards" and "flags" in the programming, blocks that would add or take away indirect light. "And sometimes, we just had to throw physics out the window and do what looked right," Walvoord stated.

Nina Bafaro, one of two lead animators that includ ed Doug Dooley, said that although extensive refer ence material of the real rabbits and moths was used, both characters are highly stylized to capture the storybook quality of Wedge's vision. That vision is what changed Bafaro's mind about computer animation. "I came from a traditional animation background and didn't like computers," she said. "But when I saw Bunny-even early on, before she had fur, I knew that Blue Sky was the only computer-animation studio I could work for. The company has a real respect for traditional animation roots."

Bafaro, who with Dooley was responsible for the majority of the scenes in the film, said she was especially sensitive to the characters' physical pre sence, adding "with the moth, the focus was on giving weight to the body, almost as if it is a strug gle for him to stay airborne. Bunny was this crotche ty, bitter, old woman character, so her move ments had to be feeble and full of effort-but with quick expressive rabbit ears and body movements."

Jim Bresnahan, who also animated for the film, said getting physical substance to read on screen has a lot to do with timing and physics. "A good animator has to be a bit of a scientist as well as an actor," Bresnahan explained adding "what's unique about Bunny and Blue Sky animation in general, is an attention to character development. We aren't just out there moving limbs up and down like puppet eers. We try to understand the character's history and motivation. It is that aspect of a real perfor mance that gives our work a lot of heart and believability."

The score is also an original-composed by Tom Waits and Kathleen Brennan who have collaborated on a number of films including Dead Man Walking, One From The Heart, (which garnered an Academy nomination), Night on Earth and American Heart to name a few. The music for Bunny, has an emotional range that journeys from an unusual accordion hymn-like solo to an instrumental chaos most remi niscent of an orchestra warming up. Waits lends his infamous gravelly vocal style to lyrics he wrote for the ending credit roll.

"The key to Bunny," Wedge concludes, "is that it is a film experience and a story first. We just happened to go insane with the technology, but it is designed to hide the fact. There are no plastic surfaces, noth ing that has a defined computer signature and no particulary graphic special effects. We don't want people to think too hard about what went into creat ing it. We just want them to sit back and enjoy it.