The graphic details

"COOL!" says Bart Simpson, stepping through a 2-D wall in the family's Springfield bungalow and popping out - literally - into a surreal 3 D world of grids, cubes, cones and floating teapots. Maybe just as cool as Pacific Data Images, the computer animation company that created it for a Simpsons Halloween special. But they'll tell you that themselves.

They do "incredibly cool animation projects", according to the corporate Web site, and "cool" is the favourite word of company founder and president Carl Rosendahl, whose "office" is a cheerful shrine to interesting toys and models. He's around 40, but disconcertingly could pass for one of his cool young twenty something animators down the hall, rolling mice in front of their big Silicon Graphics workstations.

PDI is currently working in great secrecy on a feature length computer animated film entitled Ants, with Woody Allen voicing the main character, a downtrodden worker ant in what sounds like an Orwellian insect collective (details are scarce). A company newsletter snitched in the lobby reveals Sharon Stone is the voice for the female lead.

But more immediately, PDI is waiting to see how the world reacts to its special effects sequences in Batman And Robin, the latest cinematic adventure with the dynamic gothic latex duo. "The stuff we're doing is incredibly cool stuff. It's very visible on screen," enthuses Rosendahl.

PDI has worked to some degree on all the Batman films, specialising in "digital stuntmen", including a CG (computer graphics) version of Val Kilmer's caped crusader in Batman Forever. Rosendahl is sworn to silence until after the film's opening (it hits screens on this side of the Atlantic at the end of the month) though he will say only that digital stuntmen are a big part of their work in this film, too.

PDI has a low public profile, but they've done some of the bestknown effects in the movie business, for films including Ghost, Terminator II, True Lies, Natural Born Killers, Star Trek VI, The Arrival, Eraser and Toys. They're probably best known for Michael Jackson's stunning Black And White video the one with all the morphing heads. The reaction to the video - there's framed segments of various head transformations hanging on the walls in PDI's Palo Alto, California studio - still wows Rosendahl.

"We'd been doing stuff using that technique for probably a year at that point, which seemed like a long time," he says. They developed their own software to make the transformations exceptionally seamless. "We decided, OK, this will be the big one that we go out with. It will be our swan song with morphing thing. But it started this morphing craze," he says.

"Suddenly, the amount of work! I mean, the phone calls we got, for the next year and a half, for morphing! People were designing whole advertising campaigns around that one technique and using it just because it was cool and not because it added any value to what they were doing," he laughs.

For years CG was a rarified business confined to a handful of skilled houses catering to the increasing needs of the film and advertising industries. Hollywood really only began a slow dance with digital special effects after the success of George Lucas's Star Wars. Lucas had to set up Industrial Light and Magic to handle his own effects demands, and three of the biggest players in the animation industry have remained constant since then: ILM, its spinoff Pixar (purchased by Apple founder Steve Jobs), and PDI, in which Steven Spielberg's DreamWorks SKG bought a 40 per cent stake last year.

All based stubbornly in the San Francisco Bay Area, 400 miles from the smog and glitz of Los Angeles. ILM does special effects, while Pixar shuns film effects and now works entirely on film animation. PDI does a mix of the two, a smorgasbord of commercials, film special effects, music videos and in house short animation features. Then came Pixar's Toy Story, the first feature length all computer animated film.

In the late 1980s, before Toy Story, PDI had tried to pitch a few ideas for feature length computer animated films in Hollywood. "We were unanimously met with blank stares and the question: `But no one would ever sit through an hour and a half of computer animation, would they?' You know, they didn't even care what the story was, what the characters were, anything," groans Rosendahl.

Then Disney cut a deal with Pixar to produce Toy Story. PDI bounced back - when they went to DreamWorks SKG in 1995 with three projects, Spielberg's company proposed that they work instead on a project with Jeffrey Katzenberg (the "K" in SKG and the man who set up the Pixar Toy Story deal while at Disney). Soon after, PDI was looking for capital to expand, and DreamWorks stepped in as a major investor.

Spielberg is engrossed in his live action films and isn't involved in Ants in any handson way, says Rosendahl, but they work closely with Katzenberg. DreamWorks brought in some outside writers but otherwise the film is a PDI project. Sketches for Ants characters and scenes line the walls and cubicles at PDI, looking more Roald Dahl than Disney. One feverish drawing of an insect meltdown is accompanied by the caption: "An ant is reduced to a bubbling pool of liquid by termite acid." Another scrawl beneath further sketches reads: "What a bunch of losers. Mindless zombies capitulating to an oppressive system. No wonder Woody Allen's involved.

A rival film is making Bugs, for a similar 1998 release time, but Rosendahl is philosophical. "We're both making films about insects but it's like, you can have Star Trek and Star Wars. No one's out there saying, `hey, they're both films about guys flying around in space; what's going on with that?' The thing is that you want everyone to be successful. The worst thing that could have happened was for Toy Story not to have been a great film. You know, it would have slowed the whole industry down. There's room for everyone.

The industry has a genuine friendliness, says Robi Roncarelli, an animation industry analyst and publisher of industry newsletter Pixel.

"Many of the people in this industry built it together, and it is a people business - creativity is still paramount, no matter how good the systems are. People move from company to company, so many have worked together as well." He notes that there's plenty of work to go around: worth $11.6 billion in 1996, the special effects and animation business is predicted to morph into a $32 billion industry by 2002, with film and television production accounting for a third of that.

Like Pixar, PDI cut its teeth on commercials and "broadcast graphics" (animated titles and opening sequences for television), while simultaneously encouraging employees to produce short feature films to hone creative skills. Several of these, such as Locomotion, Gas Planet and Sleepy Guy, have won awards. Their 3~ 1/2 minute CG Simpsons segment also scooped an armload of prizes.

Visual insider jokes abound in the 3-D world Homer discovers by accident when hiding behind a bookcase from wife Marge's sisters. The green and black gridded world is borrowed from the films Tron and The Black Hole. Mathematical equations float around, along with typical computer animator models for learning shapes, shadows and reflections cones, cubes, and teapots. In one corner is the temple from CD Rom game Myst.

There were numerous revelations: when Bart enters the world to try to rescue his dad, animators discovered that his 3-D hair was "a bunch of little cones'. The segment took four months to complete ("Man, this place looks expensive," comments Homer).

Such attention to detail - an animation team once was sent out for a mambo lesson when an advertisement character had to dance - gives PDI a high profile within the industry.

PDI "are one of the few companies that still write and use their own software, which means they can adapt to new needs quickly", Roncarelli says. Thus, they're "always at the leading edge of technology and creativity."

Heading out the front entrance at PDI, there's a large framed Simpsons drawing, a giant "thank you" signed by the entire Simpsons team. Someone has written "PDI: Pretty Damn Impressive."