According to visual effects supervisor Ed Jones, there are two big differences between CGI dinosaurs and CGI dogs and cats. One is fur, which has been one of the most difficult things to replicate in the digital realm. The other is familiarity. "With something like Jurassic Park," says Jones, talking about his latest project, Cats & Dogs, "you've never seen a dinosaur, so there's a lot of leeway in creating them. But you've seen cats and dogs—people live with them, and love them."

Little do pet owners know, however, that their canine friends have been fighting for thousands of years to stop cats from taking over the world. That's the premise, anyway, of Cats & Dogs, a live-action cartoon in which Lou the beagle puppy (voiced by Tobey Maguire) tries to foil the evil plans of Mr. Tinkles, a power-mad white Persian (Sean Hayes). Voice talent on the doggy side includes Susan Sarandon, Alec Baldwin, Michael Clarke Duncan, and Joe Pantoliano, while Jon Lovitz takes on the vocal role of Mr. Tinkles' feline cohort, Calico. Larry Guterman directs the film, which also features Jeff Goldblum and Elizabeth Perkins in two-legged roles, and Warner Bros. will release it July 4.

Full CGI is only one of the techniques used by Jones' team on Cats & Dogs' 900 visual effects shots. Overall, the goal was to achieve animal performances that are photorealistic to a point, but then push into a wider range of movement and expression—these dogs and cats gab, plot, wisecrack, and fight ninja-style. "We undertook the planning process like animation," says Jones. "We broke down the script and storyboarded the scenes, and built a story reel for the movie. With that, we plotted out what technologies we would use." Essentially there are three—face replacements on live animals, as in Babe; animatronic puppets; and full CGI creatures. "There was a constant dialogue, especially in preproduction, between the animatronic people, the animal trainers, and myself," he says. "We would say, 'Can you do this?' The animal trainer might say, sure, I'll get him to do that. So then I didn't have to think about getting a CG animal to do the stunt."

Generally, though, "the action scenes are all CGI animals. You can't have live ninja cats fighting a dog, or parachuting off remote control airplanes." Animatronics, which were supplied by the Henson Creature Shop, were used for less strenuous activity. "They pushed the boundaries with Tinkles," Jones says of the Henson artists. "They put the most development into him as far as the ability to control small areas of the face or ears, and to have a flexible spine. We got a lot of performance out of the animatronics." The limitations became more apparent in closeups, where face replacements were usually employed. "We tried to set a goal of not having more than two technologies in any one sequence," says the effects supervisor. "But we do use all three in many scenes—we've even taken some of the animatronics and done face replacements on them."

In creating the computer-generated pets and face replacements, the primary vendors on Cats & Dogs, all of whom used proprietary software, were Rhythm & Hues, Tippett Studios, and Mill Film, Ltd. "Rhythm and Hues and Tippett have really pushed the bar as far as synthetic animals," says Jones, who adds that dissected cats were even studied by the artists for a better understanding of skeletal and muscular structure. "You've had things like Mighty Joe Young and Dinosaur, which had some furry animals, but this takes it much further. We've grown two million hairs on Cats & Dogs. We've been able to shape it, and have dynamic controls for movement."

The Los Angeles-based Rhythm & Hues was assigned the aforementioned ninja sequence, as well as Mr. Tinkles' performance in large part. "I felt their hair technology was further along than anyone's," says Jones. "You don't take a totally synthetic white Persian cat, put him a foot from the lens, and not have the technology to pull it off." Capacity was also a major issue, since a character like Mr. Tinkles could take up to 30 hours per frame to render.

One big project for Tippett Studio, the Berkeley-based company best known for creating menacing creatures in everything from Jurassic Park to Starship Troopers to this summer's Evolution, was a treacherous Russian cat sent by Mr. Tinkles to sabotage the dogs' plans. Mill Film, based in London, worked primarily on face replacements, an assignment the company also handled on Babe: Pig in the City. "We didn't just do the snouts, like on Babe," says Jones. "We went further and manipulated the eyes, and the area from the eyes all the way down to the mouth. Because there are over 300 shots with dialogue, I felt most confident with people who had the experience, and who could push to the next level. There are a lot of exaggerated expressions that make it cartoony, but are also believable to the performance of these animals. When you have a cat who's trying to take over the world, he's got to have a certain amount of lunacy to him.

"I look at it as, a lot of the cat and dog owners I know, me being one, already believe that their animals do these types of things," Jones continues. "I sit here and I'm the worst critic, because that's my job. But I've already bought that the animals can talk; I'm more interested in their performance. When it gets to the point where you're in a discussion about how a cat might catch a boomerang, then you've totally leapt over all other considerations of believability."

All images copyright 2001 BW. & Village Roadshow Films Ltd.