Claridges Hotel, London
10 December 2009

“We can hold our head high that we got the picture done on time by the skin of our teeth,” James Cameron announces to the journos assembled for the Avatar press conference in Claridges’ ballroom. “It's really just a huge relief to actually let people see it, and quit talking about it.”

It’s little wonder the filmmaker is so relieved. After four years in the making, $237 million and a gargantuan amount of hype, Avatar is finally being released in the UK and US on 17 December 2009.

Also in attendance at the press conference ahead of the film's London premiere are cast members Sam Worthington, Zoe Saldana, Stephen Lang and Sigourney Weaver, who all wax lyrical about its dazzling technical achievements. “It blew my mind… It’s something so new and beautiful,” Saldana gushes.

However, for Worthington at least, the cutting-edge technology – especially the motion capture – was accompanied by concerns. “I was worried and panicked that the nuances of the performance wouldn’t translate once you go through the bits and bytes of a computer,” he admits. “But in my opinion that is my 100% my performance. Every glimmer in my eye, every smirk, every goofy walk. That has encapsulated my spirit. You sit there and watch the film, and hopefully after 20 or 30 minutes, you don't see blue people, you see the spirit of us.”

Cameron is certainly enthusiastic about motion capture, and rejects any notion that it’s trickier to direct actors away from sets or locations. “The interesting thing about working with performance capture is that it’s probably the best director-actor relationship or working practice I’ve been involved in… I’m not distracted by the lighting or the time of day or if the sun’s setting and I need to get a shot done by 6.15 or where’s the dolly track going to go, or the thousand questions that pull a director’s mind away from the process of working with the actors… So we spend all our time looking for emotional truth or the truth of the character.”

Cameron goes on to explain how the look of Pandora, the lush alien world at the centre of the story, was influenced by his underwater jaunts (the director owns a submersible, and has made two underwater-themed documentaries, Aliens of the Deep and Ghosts of the Abyss). “I’ve seen things that are absolutely astonishing at the bottom of the ocean. It really is like an alien planet… The deep ocean, and even the shallow ocean, is a guiding inspiration for creatures. And sometimes even just the textures – the Banshee wings are based on the colouration of tropical fish for example.”

He explains how the story of humans attempting to exploit the natural resources of Pandora – by force if necessary – was meant to echo real human history. “I think there's this long history of the human race written in blood, going back as far as we can remember. We had a tendency to just take what we want without asking, as Jake [Worthington's character] says. I see that as a broader metaphor, not as intensely politicised as some people would make it. Broader in the sense that that is how we treat the natural world.”

Though Avatar is obviously a celebration of nature, it also seems to be a celebration of technology too. “We used technology to tell a story that's a celebration of nature, which is an irony in and of itself!” Cameron muses. “But I think that it's not that technology is bad, it's not that a technological civilisation is bad. It's that we have to be in control of our technical process.”

Cameron ends by responding to the inevitable question about a sequel. “I always said during the making of the film that I dreaded the movie making money, because we'd have to do it all again,” he says ruefully. “Everything you saw up there on the screen had to be made by people at work stations over a period of years. And so they have value. The pitch was, look, you're going to spend more money on the first one, but on the second one we'll be able to advertise that, and we can focus on the story - and they bought that! I feel like I have to make a second one now… I have a story worked out for the second film and the third film. But my lips are sealed!”

Avatar is released in UK and US cinemas on 17 December 2009. Click here to read the review.