The production of Jurassic Park's special effects by Industrial Light and Magic started out on quite a different foot than most of the companies other projects usually do. Mainly, the company had to convince Steven Speilberg that they could accomplish the job at hand, and that Steven, as the director, should let them have the job of creating the dinosaurs for the movie. It was originally intended to use stop and go animation to render the dinosaurs. But the animators at ILM had other things on their mind.
After their sucess with Terminator 2, ILM was riding high, and felt for certain they could accomplish more than simply the rod removals and stampede scene they were originally slated for. By building a skeletal model of a T-rex, and then animating it, the graphics team was able to convince the producers to give them a test run on creating the CG dinosaurs. The test produced by ILM consisted of a small herd of Gallimimus. The entire thing was drawn over a still photo of an African plain, and there were two simple shots of the animals running by. But they were enough to convince Steven Speilberg that there was a new way to create his creatures.
Even with the Gallimimus stampede sequence, ILM wasn't satisfied. They wanted a crack at the Tyrannosaur. Borrowing a 5-foot model from the production crews, ILM took it to Cyberware Laboratory, and using a laser scanner captured the model on the computer. The scanner consists of a revolving laser beam which focuses on an object and can transfer topographical data onto the computer for manipulation. With a working 3D model of the T-rex, ILM created a small shot of the dinosuar chasing after some of the smaller Gallimimus. Several other programs were used for the skin and texturing, but the final shot was very crude by today's standards. However, considering the amount of time spent, and the effort put in, the shot was incredible enough to convince the producers of the film to scrap all of the stop and go motion and to work with the computer graphics.
Now that ILM had the project, they really had to get to work. Creating the model for the dinosaurs was the easiest part for the computer graphics artists. Using much of the same technology as they had in Terminator 2, they scanned scale models of the dinosaurs and began animation work. The real challenge lay in making the creatures as realistic as possible. The T-1000 from T2 had been just a metallic surface over a wireframe. The dinosaurs required much more sophisticated textures, including everything from their yellow teeth and rough skin, to watery eyes, and dirty spots. Every little detail had to be able to hold up for near twenty seconds on film; which is a lot of time in the computer world.
A second variance from Terminator 2 involved how the dinosaurs would move. With the T-1000 there was no concern over muscles, or bones. The dinosuars had to give off the illusion of living, even breathing creatures. Three pieces of software were required to achieve this: Sock and Envelope, and a new version of SoftImage.
Sock was a remnant from Terminator 2, which allowed the programmers to join a network of points (called a patch-mesh) which made up each piece of the creature. Sock would then connect all the pieces together to create the illusion of on solid moving entity. The second program was new. Envelope was a new program that allowed animators to control points underneath the surface of the skin, inessence creating the illusion of muscles moving, bones rotating in their sockets, and even the appearance of breathing. The new version of SoftImage contained a major improvement on standard hierarchial computer animation. It gave the programmers the ability to move one piece of the dinosaur without necessarily redrawing all the other pieces as well. Visual effects co-supervisor Mark Dippe explained it very well in "The Making of Jurassic Park."
He says:
'In hierarchial computer animation, we would build a human body, for example, rooting the body at the hips and then attaching the chest, shoulders, head and neck in order. So if we rotated the hips, everything above the hips would rotate as well. But what if we wanted this body to walk like John Wayne, with the hips rotating and the head staying straight ahead? Then we would have to go in and rotate the head back by hand. Hierarchial animation is a pain because it requires constant adjusting. SoftImage allowed us to treat the model more physically - we could make a move and the aimation program would automatically adjust all the other angles. We still had to go in and make mior adjustments by hand but it was light years ahead of the old method.'
The applications for making the animation look real were all at hand. The process of animating the dinosaurs still loomed ahead. But a new idea came forward that allowed for a combination of two types of technology, the stop go motion, and computers. The Dinosaur Input Device (DID) worked like a model of a dinosaur, with an animator physically moving it from frame to frame. But instead of filming the model, the information was brought from the model to the computer. By animating the DID, the artists then had access to the motions of the dinosaurs they needed, could apply textures and other effects, tweak the shots until they worked right, and save hours of time that could have been spent animating the images in the computer. The DID saved time and was a breakthrough in transferring from one type of technology to another, letting old masters at stop and go animation get into the newer wave of special effects.
When all was said and done, nobody really cared about the amount of effort put in by the artists. The audiences were too busy being enthralled by the dinosaurs on screen. What they saw were living, breathing, walking, roaring animals that had not been around for over 60 million years. Such creatures had never been seen in a movie before. ILM had pushed the bar just a little higher.