When William Joyce met Chris Wedge in 1996, they hit it off right away. They had been introduced by an executive at Twentieth Century Fox who thought the studio's Blue Sky computer-animation division might be the shop to turn Joyce's children's book "Santa Calls" into a movie. As it turned out, "Santa" never got off the ground, but even in that first conversation, Joyce and Wedge, one of Blue Sky's founders and its creative director, knew they would work together someday on something. The one sentence they both remember from that long-ago conversation is, "Let's make a movie about robots." For the last four years--years of "white-knuckled labor," in Joyce's words--that movie about robots has been their joint obsession. In the credits, Wedge is called the director and Joyce the production designer, but both men say the titles are almost meaningless. "Computer-animation studios work the way silent-film-comedy studios worked," Joyce says. "Everybody throws in their two bits." Over the course of the project, everyone at the studio became as obsessed as Joyce and Wedge. "One day at Blue Sky," Joyce remembers, "I brought in this weird hand-press juicer from God-knows-what era. I had about 10 people, 10 college-educated, way-smart, on-the-dime, top-of-their-field people, clustered around it, examining the dents, the wear patterns, the subtle changes in patina. Two hours later and we're still standing there as if we'd deciphered the Rosetta stone. At the time, none of this seemed odd."

When "Robots" finally opens this weekend, their obsession won't seem odd to anyone sitting in the theater either: it's resulted in a dazzling film. Anyone familiar with Joyce's lavish children's books, such as "Dinosaur Bob" or "George Shrinks," will recognize his trademark blend of artistry and anarchy. Fans of Blue Sky's "Ice Age," or Wedge's Academy Award-winning short "Bunny," will see that the studio has lost none of its touch for warp-speed pacing and baroque sight gags that seem to run on helium. But "Robots" is more than the sum of its nuts and bolts. Quite simply, it's the best piece of computer-animated eye candy any studio has ever produced. To find an apt comparison, you have to reach back to Disney's golden age, to films like "Pinocchio." "Nobody can touch Blue Sky when it comes to how their movies look," says Joyce, who has worked with Pixar and is currently involved with Disney in a computer-animated version of his book "A Day With Wilbur Robinson." "The staff at Blue Sky asked me what I thought the movie should look like. I said, 'Like it was photographed by Vittorio Storaro' "--the cinematographer on "Apocalypse Now" and "The Last Emperor." "And damned if they didn't pull it off."

In the opening scenes, we enter a world populated entirely by robots, a world made of metal. The birds pecking on the sidewalk are wind-up toys. In a residential neighborhood, a homeowner isn't mowing his lawn--he's buffing it. A bakery shop is called Buns of Steel. And when it's time to make a baby, you get a kit and assemble it. For minutes at a time, there's so much to drink in that you completely forget to keep up with the plot. Which isn't such a bad thing, because the plot is the most ordinary part of this extraordinary film--when it comes to creative storytelling, Pixar still rules that roost. In "Robots," a young, idealistic 'bot, Rodney Copperbottom, comes to the big city to make his mark, makes plucky, funny friends, fights corporate bad guys, succeeds in the end by staying true to his dreams. But what you'll remember are the things you haven't seen before, like the wild ride on the Crosstown Express--part Mouse Trap, part Hot Wheels, part roller coaster--that Rodney takes upon arriving in Robot City. This ride is a piece of airborne animation so dizzying that you'll wish they dispensed Dramamine at the popcorn stand. As for Robot City itself, the burg looks like Fritz Lang's "Metropolis" re-engineered by Rube Goldberg. "We wanted everything to look like the inside of a watch," Joyce says. They got their wish.

To say what "Robots" is, you first have to say what it isn't. It's not a futuristic movie. There aren't any spaceships or rockets. Nor is there much of the art deco sleekness that Joyce has mined so lovingly for his own books. This is a world much like ours but purely mechanical, inspired by its makers' fondness for widgets and gadgets. "We haunted old junk shops and auto-salvage yards, equipment-supply places," Joyce says. "I'm not a junkyard kind of guy, but I now know a number of machinists, junk dealers and junkyard dogs by name." He started building cities out of utensils in his own house. "My wife couldn't find a can opener, a corkscrew, or our coffee, sugar and flour tins. The kids couldn't find their protractors, because they were in my Rivet Town diorama."

Nearly every character and building in the film was inspired by a real machine, engine or some weird combination of parts. Rodney's most influential ancestor was an Evinrude outboard motor owned by Wedge's grandfather. "I kept thinking, That thing looks great--trustworthy, loyal, brave, friendly," Wedge says. "So Rodney is that motor with a little bit of Volkswagen minibus thrown in." To its credit, the movie never just rolls over for technology. Its villains are corporate honchos who want to convince you that nothing is ever good enough as it is--you must always upgrade. "There isn't one single perspective the movie takes," Wedge says, "because there are so many perspectives about technology. I love my computer. I also love my old tube amplifier at home and my wooden sailboat. But from the very beginning, what we wanted to drive the story is the threat of obsolescence that all these robots experience. It's the mortality we live with every day."

Even now, neither Joyce nor Wedge can quite believe they were allowed to do what they did. "There were days when it was too much fun," Joyce says. "There were months when it was too much fun. It was like getting paid for recess. A large multinational company spent tens of millions of dollars so we could go nutty over a juice strainer? How often do you get away with such epic silliness? I doubt we'll ever get away with it again." Anyone who sees "Robot" can only hope he's wrong.