From an animation perspective -- and performance capture is still very much animation intensive since the data is nowhere near dense enough to drive a face right out of the gate -- it's all about fast iteration to hone the best possible look.

But improvements in lighting and rendering were crucial as well. "Christmas Carol was a crazy experience because we had to build a studio and finish a movie in two years, and we had to use brute force technology," suggests Kevin Baillie, the visual effects supervisor and co-founder of the new company, Atomic Fiction. "Mars, on the other hand, was chock full of new technology. We looked at the concept art of Mars and said there's no way we can do this with traditional lighting methods. So we developed entirely new workflows with RenderMan that's heavily point cloud based. We used point clouds for reflections to do all the shiny surfaces; we used point clouds to cast light on the walls in the light and in the ancient underground; and most of the light cast on the characters is coming from these point clouds, even the sub scattering of the skin was point-cloud-based. It actually allowed us to have lower render times. Traditionally, this is extremely expensive to do in PRMan and, again, get that iteration going, so we were using indirect bounce lighting everything and a lot of times it was the primary light source: running down the hallway corridors. In a lot of those shots, it's being lit from the actual strips on the floors or in the walls through point-cloud-based illumination. So it was going from '90s technology to stuff that hasn't been done before on this scale."

In terms of compositing, IMD was solely Nuke-based and so they custom-built a bridge to PRMan, allowing compositors to do more of the reflections, for instance, instead of going back to lighters. Animation was done in Maya; hair and cloth in Maya, Maya nCloth and Disney's proprietary hair and cloth systems. Particle effects were done in Maya, Maya Fluids, Houdini, 3ds Max and FumeFX. Water was done in partnership with Stanford using the latest version of the PhysBAM engine.

But to bust out of the cold, gray, oppressive world on Mars, they devised an ancient underground with a colorful lichens on the walls. This turned out to be a challenge as well. "We were designing it as we were executing it as we were lighting it, so it became this massively parallel design phase," adds Baillie.

"One of our look dev leads, Robert Marinic, sat with it for a month. At the end of the day, most of the glowing lichen is procedurally placed: it falls in the cracks and other areas that it would make sense for it to grow; and the color aspect of it was a procedural shader that fell into a point cloud, which also lit the entire scene. So it was this perfect harmony of technology and aesthetics that's truly beautiful.

Finally, IMD fully embraced 3-D on Mars, taking shots earlier into stereo layout, putting eyes on every one before they hit animation. In fact, one of the most stunning moments is a climactic shattering of a helmet achieved through simulation. It took until the last minute to get right, differing from Wells' plan, but it was a happy accident that worked marvelously. "Everybody gasped during the audience screening I was in," recounts Baillie. "That's a great feeling to have an effect that evokes a physical response in people."

Bill Desowitz is senior editor of AWN & VFXWorld.