'Madagascar' pushes tech limits

(continued from previous page)

time, the color palette has expanded from four colors to 250. The landscape of Madagascar, he said, contained 150,000 different objects moving at once.

DreamWorks harnessed computational power from Advanced Micro Devices' Opteron chips and Hewlett-Packard, which licensed workstations, servers, notebooks and laptops to render the images. The animation group, based in Mountain View, Calif., also develops all of its own proprietary algorithms for lighting, surface animation and characters.

"It took some elegant programming to compress those files and render the images," said Eric Darnell, co-director of "Madagascar" and the 1998 release "Antz."

Although realism prevails in other animated films, DreamWorks strove for an even more stylized effect for "Madagascar" that harkens back to an old trick of hand-drawn animation called "squash and stretch."

To illustrate the technique, in one drawing a red ball appears perfectly round, and as it is thrown into the air in the next drawing, it appears oval or stretched out. Finally, it flattens as it hits the ground in the final picture. Simply put, that is the craft of key-frame animation. But today, computers calculate the mathematical algorithms necessary to connect the dots.

The characters in "Madagascar" were modeled after cartoon figures of the 1950s and 1960s, like those in Hanna-Barbera classics, for "a zippy, squash-and-stretch feel," said Kendal Cronkhite, head of production design. Unlike the character of Shrek, which was anatomically correct, the stars of "Madagascar" were literally models of tubes in the computer so that they could be contorted in ways imperceptible to the eye, yet still stay true to their character, Cronkhite said.

"We built into the computer anatomy of the character this range of motion that's imperceptible to the eye but creates a cartoon effect," said Rex Grignon, who was in charge of character animation on the film.

To produce any animated film, the creators first model the characters and environment, sometimes with clay or hand drawings. The production team will work on the surfaces of the environment, such as colors and textures. The lighting and design team works on the layout and camera angles as well as the landscaping. The animators also begin bringing the characters to life on the PC.

In the last 10 years, computers have come to dominate the animation field, which has long been a hand-done art. Master animators used to sketch what's called a key frame--for example, a boy with his arm cocked to throw a football. Then the next frame drawn would be of the boy with his arm forward with the ball leaving his hand. Whereas animation once hinged on books of frames that could be "flipped through" to create the illusion of fluidity, software developed to a point at which it could render the sequences and movement between each frame.

Now animators don't need to sketch frames; it's all done with the click of a mouse. However, DreamWorks and others begin with hand-drawn pictures, and in some cases, clay models of characters.

For "Madagascar," the design team developed five different kinds of lemurs with 12 variations of hair type, or 60 possible combinations for characters.

"It took a mix of technology and creative to make that work," Cronkhite said.