It took Pixar four years to realize writer/screenwriter Brad Bird's vision for his story about one of the world's top crime fighters, now married with kids and adjusting to life in the suburbs. The film opens in theaters Friday.
Bird unwittingly demanded some of the toughest stuff to digitally animate: hair, fabric, dozens of scene changes and, most difficult of all, people. And not just one person, but a family of five and a group of supporting characters -- all of whom get close-ups.
``With the movie we took the 10 hardest things to do in (computer-generated animation) and did all of them in generous amounts,'' said Bird, slouching low in a conference room chair at Pixar's Emeryville campus last week. ``A lot of people have thought we were nuts. We were, actually. But somehow, we got through it and we're still alive and functioning.''
Bird already has a considerable reputation within the animation community. He brought his artistic talents and eye for family dysfunction to a pair of irreverent television series, ``The Simpsons'' and ``King of the Hill.'' And his first animated feature, ``The Iron Giant,'' won broad critical acclaim.
For ``The Incredibles,'' animators started by creating a computer-generated skeleton for Bob -- later replicated -- for the other main characters -- that could move in realistic, human ways. The animators focused on accurately capturing the rotation and articulation of major joints, like the shoulder, knowing that would be key to maintaining the illusion of reality.
``If all the motion is localized in the shoulder joint, it looks stiff. You look at it and say, `He looks like a reincarnated zombie,' '' said Sayre, who demonstrates proper shoulder movement and starts slinging anatomical expressions like a first-year med student.
Next, computer animators built muscles that would bulge and flex in all the right places. Like gym rats, they focused their work on major muscle groups that would convey Bob's super strength: the pectorals, the deltoids, the trapezius and the laterals of the upper body and back.
The muscles attach to the digital skeleton and reacted authentically. The deltoid muscle would properly ball up at the shoulder, say, when Bob raises his Barry Bonds-like arms.
``We didn't have all that,'' said Sayre. ``We had to invent it.''
Atop its pioneering design for computer-generated skeleton and muscle, Pixar developed a technology called ``goo,'' that simulates how the skin glides over the muscles and pinches like our own flesh. Whenever Bob raises an arm, an algorithm automatically creates a cavity under the armpit and draws the skin tightly against his rib cage.
Another challenge is capturing the way light is absorbed and reflected through the skin. Pixar's technicians devoted several months developing software to emulate the skin's opacity, so that when a character is back-lit his or her ears will be reddish-opaque.
The first time animators lighted a character, it sprang to life.
``It kicked things up a lot. It was like, `Oh. That looks alive,' '' recalled Bill Wise, the film's character supervisor.