'Avatar' all about innovation

Cameron up to the challenge: to seamlessly blend CG ani and live action

Seventeen months before the release of James Cameron's sci-fi epic "Avatar," anticipation in the industry is enormous. The project will be made in stereoscopic 3-D and combine live action and computer animation using visionary new techniques.

Slated to open Dec. 18, 2009, Cameron's first narrative feature since "Titanic" has been in the works for 21/2 years. He expects "Avatar" to be about 60% CG animation, based on characters created using a new performance capture-based process, and 40% live action, with lots of VFX in the imagery.

"It's is the most challenging film I've ever made," Cameron said.

The live-action principal photography for "Avatar" was shot in New Zealand in the fall and winter using the Fusion 3-D camera system. Cameron first used the Fusion to make his 2003 Imax 3-D film "Ghosts of the Abyss"; he and "Ghosts" director of photography Vince Pace invented the camera system.

Now, Fusion camera systems are available for rental via Burbank-based 3-D provider Pace, through which president Pace and Cameron continue to develop the technology. The system already has made its mark, having been used on the live-action digital 3-D titles "Hannah Montana/Miley Cyrus: Best of Both Worlds Concert Tour" and "Journey to the Center of the Earth."

Said Pace: "The systems themselves, in my opinion, can handle any creative challenge. We've learned a lot since 'Ghosts of the Abyss.' "

With "Avatar's" principal photography completed, Cameron is now focused on CG production. The helmer said his team has completed the performance capture (sometimes referred to as motion capture) of the actors and is in the post process of performance-capture 3-D.

The CG involved a large amount of additional R&D that afforded the director new creative options and flexibility. For one, the film used a new performance-capture production workflow.

"The way we developed the performance-capture workflow on 'Avatar" is we have our virtual camera, which allows me, in real time, to hold a camera — it's really a monitor — in my hands and point it at the actors and see them as their CG characters," Cameron said.

The actors wear leotards and a "head rig" with a tiny standard-definition camera that takes an image of the actor's face. "That is going though facial algorithms and going back into the camera as a real-time CG face of the character," the helmer said. "You see it talk; you see the eyes move. It is pretty phenomenal.

"Once we've laid down a take, the take exists in the digital asset management system. It can be accessed at any time. Long after the actors have gone home, I'm still out there with the virtual camera, shooting coverage on the scene. I just have to play the take back. I can do the close-up, the wide shot … I can even move them around on a limited basis. We relight it. We do all kinds of things."

Cameron also used what he calls FPR, or Facial Performance Replacement, which he likens to the film sound technique of ADR (Automated Dialogue Replacement).

To describe the process, the director related that he recently wanted to redo a line spoken by actor Laz Alonzo. "We changed the words and he redid the dialogue. We didn't have to recapture (his body performance), and he didn't have to put on the performance capture suit again. We were just creating new words, and we were creating a new face."

On the cinematography, Cameron said his goal was to create "one movie where the aesthetics of physical production and the aesthetics of virtual production are, to the extent that we could do it, pretty much it identical."

This involved development of what Cameron calls the 'Symul-cam,' which essentially treats a real camera like the virtual camera. "We're taking our virtual production toolset and superimposing it on physical production," he said. "We turned the set on the soundstage into a capture volume and turned the physical camera into a capture virtual camera, so we were able to integrate CG characters and environments into our live action."

As an example of how this works, he said: "We have people in flying vehicles, and I can see what is outside the window, fed in, in real time."

With all this, Cameron has never shifted his emphasis from storytelling.

"You have to make a good film that would be a good film under any circumstances," he said. "You have to put the narrative first. The reality is no matter how many (3-D) screens we get, you are still going to have a large number of people — possibly the majority — who see the film in a 2-D environment."