With each passing year, demands to extend RenderMan continue. With Pixar's most recent film WALL•E, director Andrew Stanton wanted to simulate an anamorphic look to evoke a widescreen, sci-fi film feeling. Batali explains, "Pixar doesn't use real lenses -- we have fake lenses. It's not a hard problem to stretch images, but the kind of artifacts that a real, physical anamorphic lens produces -- which we see when we watch a Cinemascope movie -- are the artifacts the director wanted. So we introduced a new feature -- anamorphic depth of field -- which means that the depth of field simulation inside the renderer can simulate the effects of an anamorphic lens. Unless you're extremely nerdy about looking at pictures, you'd never notice it. WALL•E also has gobs and gobs of complexity, and figuring out how to bake out various portions of the computations and reuse them is another area where we've made very significant strides over the last five years. In order to make pictures of great complexity on computers, you still have to play games.

"One of the things in the next several years will be trying to figure out ways to make things simpler than they are. To still get the visual complexity and the control that you have to have, but bring it down to the level where it doesn't require a Ph.D. in programming to turn the knobs. That's a battle that we continue to fight."

When he surveys the current landscape, Batali observes, "Studios have pipelines that are either works of art or almost Rube Goldberg machines in order to have all these multi-pass renders with sub-surface scattering." He notes that, for some, the compositing phase has almost begun to resemble a look development editing session. "They have 20 or 50 channels as inputs into their compositing scripts! I've detected a clash of cultures between those facilities that are clearly comp-driven and those that are trying to resist that particular slope. Pixar has tended to be anti-comp because our decision-makers haven't been the comping people. And there are so many decisions that you can't defer to comp. Maybe in the feature animation world that kind of comp-centric workflow is less natural, whereas, when you're doing effects, you're sitting with the director and a bunch of assets that you've produced ahead of time. Your director's time is very valuable and sparse, so you want to be able to make decisions at comp time."

Looking forward, Batali muses, "We're always looking for revolutions, but success is an evolution. We certainly have little side projects where we're exploring fairly radical alternate ideas, but, ultimately, all we can do for practitioners of movie production is make something faster or easier. Certainly, 'faster, easier and more complex' has always been our driver and I don't see that changing. There's no shortage of avenues where we can deliver the means by which richer pictures can be delivered to the screen cheaper, easier and with more control."

As Pixar marks RenderMan's 20th anniversary, the company's development endeavors are divided up into two broad categories, explains Batali. "There's the Studio Tools Group, which develops our in-house animation system, and then the RenderMan Group, which basically delivers two forks of products. One is the Pro Server, the core rendering technology, and the other is what we call bridge technology, the 'studio in a box'-type technology. That's called 'RenderMan studio' and it's broken up into a plug-in for Maya -- to output RIB and convert a Maya scene into RenderMan form -- plus SLIM, which is a shader-development environment, plus the queuing system Alfred, and a tool for viewing images. These are all basic tools, none of which alone would be 'best in class,' but their power is in their integration."

Ed Catmull may not have the time these days to grapple with the specifics of RenderMan development, but he remains intrigued by the future possibilities. "The next wave is that multiprocessors are coming out," he observes. "There'll be more processors and people will have to figure out how to use them efficiently."

And Catmull has always remained keenly aware of RenderMan's competition. "When people started to give out free renderers bundled with software, we wondered, 'If they're giving away renderers for free, how can we possibly sustain this as a business?' But an interesting thing happened. When people give away something for free, they can't afford to put resources into it to keep it at the level that it needs to be. What we've got is this small, dedicated group whose only job is to make the studios happy. Studios aren't trying to get things for free. What they want is to get the quality on the screen and they want reliability. In the end, we give people the sense of trust that they'll be able to deliver their films. And that's a source of great pride."

Ellen Wolff is a Southern California-based writer whose articles have appeared in Daily Variety, Millimeter, Animation Magazine, Video Systems and the website CreativePlanet.com. Her areas of special interest are computer animation and digital visual effects.