Issue: Volume: 24 Issue: 9 (September 2001)

Opening Doors




Software testing spawns an animated production

By Karen Moltenbrey

Images courtesy Alias|Wavefront.

The product development team's goal when creating the animated segment "Passage" was to stress-test the new features in Maya 4.0. The results, though, netted far more: a visually detailed, thought-provoking production. Using subdivision surfaces and procedural textures, the artists achieved a high level of detail for the imagery, which was essential for rendering the animation at high-definition television (HDTV) resolution.

"Passage" is the most recent animated project created at Alias|Wavefront to uncover bugs and test features in a new or re vamped software release. Since Maya was introduced nearly three years ago, most of the in-house animations have been humorous 30-second mock commercials. The most notable exception was Chris Landreth's "Bingo," a dark, enigmatic piece featuring a nightmarish clown, created with the original Maya software. "Passage" takes a similarly ambitious approach with a compelling story and complex visual content.

Written by Edgar Pablos, "Passage" is an adaptation of Franz Kafka's parable "Before the Law," which depicts a metaphoric journey through life in which a man accepts the oppression of authority and fails to ultimately fulfill his personal goals and desires. To illustrate this concept, co-directors Matt Dougan and Andres Vitale created a boy character, who grows into an old man while trying to persuade a giant to allow him access to a passageway hidden behind a closed door. After spending his lifetime trying to gain passage, the old man finally asks the giant why he cannot enter, to which the giant replies that he has never tried hard enough.

"We wanted to keep the animation ambiguous, like the original story, so that everyone could draw their own conclusions from the presentation," explains Dougan. "We want it to mean different things to different people."
Artists at Alias|Wavefront used subdivision surface modeling to create detailed imagery for "Passage," its recent in-house animation production, which was rendered at HDTV resolution.




"Passage" was rendered in HDTV resolution at 1280 by 720 pixels, which required the artists to fill each frame with four times the amount of detailed data than is normally needed for a television production. "HDTV resolution is closer to film resolution, so we couldn't hide anything or it would show," says Dougan.

In a departure from previous Maya productions, the artists created all the character models for "Passage" using subdivision surfaces rather than NURBS. Although not a brand-new feature, the subdivision surface tool has been reworked in Maya 4.0 to make it easier to use. "It's more akin to how a sculptor would model as opposed to a designer," says Dougan.

Subdivision surfaces enabled the artists to create higher resolution models by adding extra geometry only in the areas where it would enhance the model. The face of the boy character, for instance, required little detail in the forehead but needed far more geometry around the nostrils and earlobes for realistic results.

"Using subdivision-surface modeling let us spend more time creating the necessary details rather than stitching together NURBS patches," explains Dougan. This modeling approach al so made animating the characters easier because the artists had to skin only one piece of geometry rather than multiple pieces, as is the case with NURBS. Texturing was likewise easier, since the process involved wrapping one large texture map rather than stretching numerous textures across all the NURBS patches.

When the co-directors began the modeling process, they had already decided on a style concept for the characters-an organic/mechanical hybrid for the giant and a realistic human style for the boy. But they did not have an exact reference for the models, which resulted in numerous iterations of each character before the directors finally agreed on the final appearance.
The animators used a new lighting control feature in Maya 4.0, which gave them more control when applying shaders and lighting to objects within the scenes.




"Andres and I would sit next to our lead modeler and say, 'Move the eyes and ears in,' and 'Reshape the chin,'" says Dougan. "And he was able to do that fairly quickly be cause he was dealing with only one object as opposed to a lot of tiny objects that he would've had to move and realign each time."

The artists completed the detailed models by using Maya's file texturing tool to apply crisp textures to the images. How ever, using only file textures would have caused the image to pixelate in the HDTV-resolution close-up shots. To overcome this problem, the artists mixed mathematically based procedural textures with the file textures, using Maya's layered texture tool.

"You just can't replicate the randomness found in nature with procedural textures. But by mixing the two types of textures, we achieved the next-best thing: realistic images with localized detail," adds Dougan. "This was critical for achieving the amount of detail we needed in many of the shots."

The artists also used Maya's 3D paint to add shading to the character models. "One of the more interesting things we found was that 3D paint could be used to blend between file textures and procedural textures, de pen ding on where on the body each type of shading was used," notes Dougan.
By using a combination of procedural and file-based textures, the artists were able to create realistic images while maintaining the necessary level of detail needed for HDTV-resolution output.




Using subdivision surfaces and procedural textures allowed the team to create one large, detailed "giant" model, from his rippling biceps to his wriggling toes-subtle secondary motions "painted" onto the model with the new Jiggle Deformer tool. These motions augmented the main character motion, which was done using the new kinematics setup, whereby the animators combined forward kinematic keyframe movements with inverse kinematic bone structures to achieve realistic action.




The artists then composited the characters into the production's two main settings using Maya Fusion. The first is an open, desert landscape created from photographs that were digitally manipulated and stitched together in Adobe Systems' Photoshop for a surreal look. The second is a steep 3D canyon setting that was also textured in Photoshop.

The two directors began working on the animation in January, but only began stepping up production in the spring. Since then, it's still been slow going, as software snafus along the way meant putting the piece aside until a particular problem was solved.

"For most animators, the production itself is the major concern. So if you encounter a problem or the shot doesn't work technically, you do a workaround," Dougan says. "We couldn't do that."

Because of time limitations, Dougan and Vitale created snippets of the production, which the group hopes will generate enough interest to warrant completion of Pablos' 7-minute screenplay.

Only time will tell whether "Passage" will evolve into a longer animation, but it won't be for lack of trying, as Vitale and Dougan are determined not to follow the path taken by the man in their parable.




Key Tool: Maya 4.0, Alias|Wavefront (www.aliaswavefront.com)
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