I’ve been reading a lot of articles on Avatar and interviews with James Cameron recently. Of course, there’s so much coverage that I couldn’t possibly get through all of it. But on the whole I was disappointed at how little information there was on Weta Ltd.’s role in the film’s groundbreaking special effects.

The Hollywood Reporter’s article by Alex Ben Block, posted December 10 and published in the December 11 print edition, is the big exception. It doesn’t get into the nitty-gritty details of the technology involved, but it gives the facts and figures to show just how much Cameron’s film relied on Weta to innovate the new techniques and to slog through the laborious process of rendering a huge number of effects shots. Here’s the section of the article on Weta:

After getting bids from ILM and others, Cameron and Landau chose WETA, the New Zealand company partly owned by director Peter Jackson. WETA’s bid was helped by a 15% rebate offered by New Zealand, but that wasn’t the main factor.

“We just had a sense they knew how to do this,” Cameron says. “And they weren’t a big, jaded outfit.”

The Wellington facility offered not just visual effects but also the WETA Workshop, which created physical props and prosthetics, and a complete studio support system. For the New Zealanders, getting Cameron would be a big catch, and they wanted to prepare. Above all, they wanted to offer him an extra technological marvel that would induce him to sign with them.

“We knew we could do the body capture in real time, but what if you could see the characters’ facial performance in real time as well?” says Joe Letteri, visual effects supervisor at WETA. “Everyone thought that was a crazy goal, but we knew Jim was coming. So we did this intensive, six-week effort to see if we could (make it work). And when he got here, we had it working.”

Cameron not only gave WETA the greenlight for FX, but he also decided to do all the live-action scenes on its soundstages. Those scenes would be shot first, with the non-live-action shoot done at the old Howard Hughes airplane hangar-turned-studio in Playa del Rey, Calif.

In addition to Winston’s team, Cameron hired production designer Rick Carter, who had worked with Steven Spielberg and Robert Zemeckis. Carter in turn brought Rob Stromberg onboard as co-production designer.

The designers passed dozens of sketches to WETA of characters, plants, vegetation, houses, vehicles, floating mountains and more. “We together created a complete ecosystem for a planet that was not just beautiful but had an internal nervous system essentially,” Carter says.

Previously, to make each plant move, an artist would manipulate it frame by frame, but that would be impossible with about 500 different types of plants, so WETA adapted a technique from “Lord of the Rings,” using a “crowd pipeline” based on MASSIVE (Multiple Agent Simulation System in Virtual Environment) software that in the past had been used to generate an army of realistic soldiers. Here, it gave each plant its own life.

To light all this, WETA — which began work in January 2007 and only ended the week before Thanksgiving — adapted a program based on “spherical harmonics,” a mathematical system used in computing that allows you to have a multidimensional view of an object. It had been used in video games but required an enormous amount of “rendering” by high-end computers; indeed, insiders estimate each frame took 20 hours of computing.

Cameron says WETA has the largest computer “farm” in the world. It ran continuously for three years for “Avatar,” as the staff in Wellington grew to nearly 900, even with ILM in San Francisco doing a few extra shots.

About 95% of the visual effects were done by WETA. They taxed the company to its limits. “The first year, we worked five days a week,” says WETA visual effects supervisor Eric Saindon. “The second year, six days. This year, it has been pretty close to seven days a week.”

A staff of 900 would be roughly twice the highest number working during the production of the trilogy. Clearly even when Peter Jackson is not personally directing an effects-heavy blockbuster, the company can keep busy. The innovation for Avatar came directly out of the revolutionary digital programs and techniques developed earlier for LOTR. Presumably that technology will be used in The Hobbit as well. I look forward to the more detailed examinations of that technology that should be coming soon in American Cinematographer and Cinefex.