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How Computer Artists Create Movie 'Actors'

Without Geoff Campbell and other special-effects artists, there was no way to remake the movie "101 Dalmatians" - except to trim the canine cast by about 99 dogs.

Disney used cartoons to fill the big screen in its 1961 version. But in 1996, the studio wanted realism. They used real actors and a few real Dalmatians.

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Mr. Campbell made the rest of the dogs out of thin air, using a computer.

Computer-generated puppies were perfect. They would do just what the director wanted. The "virtual" pooches blended in with the real ones. (Look at the photos on this page. Can you tell?)

"It took six weeks to create a puppy model of a dog that is nine weeks old," Campbell says. The process began with a ball of clay and a photograph of a dog. The clay model was scanned into a computer. Now it was a computer model, and the virtual pup could be animated (made to move around), colored, and altered in other ways.

That's what Campbell does at Industrial Light & Magic (ILM) in San Rafael, Calif. It's a well-known special-effects company. ILM is a "postproduction company." It does its work after the original photography has been done. Technicians mix computer-generated images with real film footage.

The Monitor visited Campbell to learn more about movie special effects.

San Rafael is 20 miles north of San Francisco, far from Hollywood. Here George Lucas, maker of the "Star Wars" movies, founded Industrial Light & Magic in 1975.

Campbell greeted us in his work clothes: jeans and a T-shirt. We met in a room used to fit computer users with equipment. (Computer work stations must feel comfortable for long hours of mouse clicking.)

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Campbell's office is off-limits to outsiders while he's working on Lucas's new "Stars Wars" movie, which comes out next year. Until then, everything about the film is top secret.

Campbell is part of a large team at ILM. "People come to work here from every point of the globe," he says. "At last count I think there were people from 25 countries."

He couldn't tell us what he's doing for the new "Star Wars" movie. But he could talk about "101 Dalmatians," which is typical of what he does.

For that film, the director wanted to see a three-dimensional clay model of a puppy before filming. A modelmaker sculpted a prototype. Once it was approved, the model was carefully cut into pieces. The pieces were scanned into a computer, and a computer model was assembled. That was Campbell's job as a CG (computer-generated) modeler. He made what's called a "wire frame" computer model.

It's like making a papier-mch model, only on a computer. The "frame" is meticulously shaped, expressions created, and electronic skeleton built that lets the model to move realistically.

For "101 Dalmatians," where many similar images were needed, Campbell copied the prototype dog and made changes in the copies so the puppies would look different.

Before a computer animator took over, the puppy needed skin. The frame was covered with a uniform base coat of color. A skilled computer painter added the details - including fur.

An animator programmed the movement of the computer models. For "101 Dalmatians," that meant developing basic walking and running programs and using them to animate the puppies. The running speeds and motions were varied so the puppies looked more realistic.

The final handoff in this team effort was to the technical director. His job was to take this CG puppy and make sure it was seamlessly entered in the movie. (More on that later.)

SINCE coming to ILM in 1990, Campbell has helped put creepy aliens into "Men in Black" (1997), dinosaurs into "The Flintstones" (1994) and "Jurassic Park" (1993), and jungle animals into "Jumanji" (1995).

When he worked on "Terminator 2: Judgment Day" (1991), computer animation was less advanced. But the CG robot in "T2" was supposed to look mechanical and expressionless. "That worked perfectly at the time," Campbell says, "because our computer software wasn't at the point where it was easy to create expressions."

By the time "Jurassic Park" was being made, the technology was sophisticated enough to create more expressive images. The dinosaurs had lifelike eye and mouth movements.

As a boy growing up in Canada, Campbell says he never envisioned doing what he does today. "There weren't home computers at the time," he observes. What captivated him was using a View-Master to peer at 3-D images of cartoon characters like Huckleberry Hound. Later he grew interested in British TV space adventures like "Fireball XL-5" and "Thunderbirds." As a teenager he constructed spaceships out of cardboard. In his first attempt at a movie-style special effect, he photographed a crash scene using a painted rocket lined up with the horizon. "I tried to tell my friends it was real, but I had a few things to learn about lighting," he says.

He knew he wanted to do something in the arts, so he studied sculpture and anatomy in college. That led to his building miniature TV sets for the British Broadcasting Corp.

"I had all these different skills that I had pulled together," he says, "but no real way of using them." Then the special-effects industry was transformed by computer-generated images.

"I wasn't sure I could make the jump technically," Campbell recalls. He took a computer-animation course, though, and found it dovetailed nicely with his abilities.

Once a movie project gets a green light, Campbell often goes right to work making a library of computer-generated models.

"You have to know what kind of performance the character is supposed to give," he says. "The models we build are models that move, so we can never view our job as handing off a static model [to an animator]. Our models are made for motion, and we always have to be thinking of that."

The computer, in a sense, is its own self-contained studio. The images it records are married to the film shot on a real set, film that is scanned into the computer.

The computer combines all the images - dinosaurs, trees, truck, and rain, for example - into one picture.

A WHOLE department is assigned to the "match move" work, which requires taking all the spatial distances and relations found in the original photography and re-creating them on the computer screen. This requires precise measuring so that images shot on film match those generated in the computer. Combining them can be a bit like assembling a jigsaw puzzle. If not done carefully, a computer-generated dog can seem to float above the ground or his paws look as though they go through the floor. A CG puppy may appear to walk in front of someone he's supposed to be going behind.

Yes, special effects are complicated and time-consuming. Making sure that all the lighting and shadows are correct for a single frame of film can take several days' work. It takes 24 frames to make one second of film.

Most movies, Campbell says, are changed right up to the minute they're shipped to theaters. So he must wait until opening night to see his work.

"That's one of the more exciting moments, good and bad," he says. "You're excited, but you're hoping your favorite shot hasn't been cut.... You don't really know until everyone else sees it."

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