It's a whole new world for Cameron

James Cameron knows the launch of "Avatar" -- his 3-D sci-fi film, the most expensive movie ever made -- won't be all smooth sailing.

The 55-year-old filmmaker admits he is apprehensive about the reaction to his first nondocumentary since "Titanic." That 1997 film created a tidal wave -- winning 11 Oscars and earning a record $1.8 billion worldwide -- making the director king of the cinematic world.

"I'd be lying if I said I didn't," Cameron says when asked if he worries. "Every filmmaker is concerned about how the world reacts to their films, and obviously, there's a lot of scrutiny on this film.

"But in a funny way it's no worse than it was on 'Titanic' or even 'True Lies.' Once you reach a certain level of notoriety, everybody's looking your way when you make a new film. So I think it kind of keeps you honest and makes you work hard."

As in his previous films "Aliens," "Terminator 2," "The Abyss" and "Titanic," Cameron is once again expanding technological boundaries.

"Avatar" involves a 3-D Fusion technology that the director has spent eight years and $10 million to develop and considers it "pretty damn good." The film uses photo-realistic computer animation and live action created by a motion-capture process, which involved 800 artists working full time for 4 1/2 years on the movie's record-breaking 2,500 effects shots.

"Avatar" tells the story of a paraplegic former Marine named Jake Sully (Sam Worthington) who volunteers for a mission on the mineral-rich planet of Pandora, where he "remotely inhabits" a cloned body that combines humans and the 10-foot-tall blue indigenous people known as Na'vi.

Cameron had the story for "Avatar" kicking around since before "Titanic," but the cost was too prohibitive in the 1990s. For the director, the film has been a lifetime process. "Avatar," he says, was a way for him to put all the things onscreen that have fascinated him since he was a kid.

"It was an entire childhood spent reading science fiction, thinking about exploration -- from watching people go to the moon to Jacques Cousteau specials -- wanting to explore, wanting to go underwater, wanting to go to other planets and finally getting to make that dream project as an adult 20-some years into a career where I got to act on all those childhood visions. I can trace it back to Ray Harryhausen movies. I can trace it back to pulp science-fiction novels and comic books. But it's really the love of fantasy imagery, the love of exploration, which takes you to new places."

Before starting to make "Avatar," there was a five-year period in which Cameron did 60 ocean expeditions and made four documentaries from those dives, including "Ghosts of the Abyss" and "Aliens of the Deep," while his new 3-D camera system was being refined.

One of his aims with "Avatar" was to bridge the gap between real human performances and replicated computer-generated performances. To that end, key members of the cast did a three-day memory exercise and rehearsal in Hawaii before shooting the film. There they trekked around the rain forest, building campfires, cooking fish, drinking rainwater from leaves and trying to live tribally.

As Cameron recorded on news HD cameras, Saldana and Worthington learned to walk through the jungle so they could replicate it in their performances before the green screen.

Cameron knows that everyone is focused on the cost of the movie, which is estimated to be $230 million to $400 million -- depending on whom you believe. He's hoping that will change when audiences see the movie, which like "Titanic" has a love story -- albeit between two giant blue people.

But the director believes that "Avatar" has a story that will fascinate audiences nevertheless.

"I talked about this at great length before 'Titanic' was released. I said, 'Yes it's got visual effects. Yes, it's got enormous sets. Yes, it cost a lot of money. But really it's in the service of a narrative.' The second that people saw the Jack and Rose relationship and went for the ride of the film -- the emotional roller coaster -- they didn't care about any of that stuff anymore. It became kind of a footnote. And I suspect the same thing will happen on 'Avatar.' "