Computer Animation

With 1995's highly successful Toy Story, Pixar ushered in a new age of computer animation in the movies. However, it wasn't the first movie or show to use computer animation in one form or another. ABC's ReBoot, a Saturday morning cartoon show, also uses nothing but computer rendered characters and scenes. Many commericals have also been made using a large degree (or in some cases nothing but) computer animation. More and more characters in movies are computer generated. But how does it all work?

The first step that any good movie-maker goes through is to visualize what their completed product or products will look like. Take Toy Story. Each of the characters went through several designs before a final character layout was settled upon. And since this was a 3D film, animators had to have 3-dimensional renderings of the characters on hand at any given time to reference their creations.

Scultures of each of the characters were created for the artists. These gave them an idea of what the finished product would look like, as well as raising some of the issues they would have to deal with later, such as scale, complexity, believable movements, expressions, and speaking.

Actors Tom Hanks and Tim Allen recorded their voices before much of the computer animation was ever started. This was to give the animators some method of visualizing what the characters would be acting like as they spoke. Most computer studios use some kind of visulization technique, usually pictures of what they're creating. In Jurassic Park, the Industrial Light and Magic animators had models of dinosaurs everywhere. In Dragonheart, the animators watched Sean Connery as he read his lines to help them create the dragons facial expressions. The Toy Story creators had the recorded lines to work off of, and while they weren't necessarily striving for reality, the recordings did help in figuring out what to have the characters do.

With everything they needed to reference, the programmers were ready to start their end of the project. All the animations for this movie were done entirely with a program written by Pixar called RenderMan. RenderMan enabled the visual effects artists at Pixar to handle extremely large renderings with relative ease. The animators had to create the shots described in the script through the use of wireframes and plotting programs. This was to come up with the necessary data to feed into RenderMan to have a surface put on the wireframe drawings. Woody, the cowboy puppet, was described by approximately 52,865 lines of code, with 712 different animation controls, 212 in his face alone. The character required 26 texture maps; in comparison, the Space Ranger Buzz required 189 texture maps. And that's not counting the maps for when he was dirty!

Working off the 25,000 storyboards prepared for the movie, the animators painstakingly animated each and every move the characters made, ending up with around 4.5 million lines of code. The process took Pixar nearly 10 man years and when finished took up over 500 gigabytes for storage.

Finally, they fed the completed scene data through the renderer to obtain the finished product. The renderer took a total of 800,000 hours altogether to animate every scene in Toy Story, but that was partially defrayed by the fact that RenderMan can be used on entire networks of computers, thereby reducing the load for each individual processor to a more managable number of hours or minutes. Once the entire film was finished, the sound, graphics etc, took 2 terabytes (2 trillion byte) of space. The 79 minutes of space was the first full length film to be rendered entirely by computer.

But that is just movies. What about TV shows? Well, it turns out that animation has even made its way into Saturday morning cartoon shows. ReBoot, produced by the Canadian company Mainframe Entertainment, is, like Toy Story, animated soley with computer rendering programs. The difference is that ReBoot, unlike Toy Story, uses Microsoft's SoftImage. It is also produced on Silicon Graphics machines, much like most of the computer graphics industry. Toy Story's final rendering was done on a room full of Sun computers.

Another haven for computer driven animation is those annoying tidbits in between the shows. I am referring, of course, to the commercials. Anyone who has seen a Dodge Neon drive through the corn fields, popping the corn on the stalks, or any other number of commercials with what appear to be impossible scenes in them, has seen computer graphics in commercials. To accomplish the popping corn, Pacific Data Images animated computer generated corn husks onto real corn stalks in a field somewhere, then created an initial veloctiy and direction for each kernel as it pops from the "hot" Dodge Neon. For the wide angle shots, they used a particle system to animate waves of exploding kernels trailing back from the car. In the final step, they used matte paintings to simulate fields full of popped popcorn using a process similar to morphing.

Whether it's computer toys, rampaging dinosaurs, heroic dragons, or a Dodge Neon driving through Iowa, computer animation has become more and more prevelant in movies and TV today. And as technology evolves and computers become faster and faster, the animation will be more and more convincing and realistic.

Pixar	Toy Story	Dragonheart
Silicon Graphics	ReBoot	SoftImage
Sun Microsystems	Visual Effects HQ: Toy Story	Pacific Data Images
Dodge/Plymoth Neon Commercial	Visual Effects HQ: ILM

Last Updated August 20, 1996