Getting It Made

Avatar's shoot was long - a couple of years at least for just the physical aspect of production - and split between regular footage with some green screen work that was shot in New Zealand and work on the performance capture "volume" - a featureless space created in hangars in the Playa del Rey area just south of Los Angeles.

The cast - at least when they were working as Avatars  - were dressed in tight velcro suits with dots all over and cameras attached to their heads.

Cameras around the room also captured footage and uploaded it to computers, which spat out real-time (if basic) versions of the virtual world and characters for Cameron to see even as he captured shots.

The raw cg-enhanced work would then be shipped off to various places, including Digital Domain and Weta digital to be turned into finished shots.

Weta's name is an important one, since the company's stunning work on Lord Of The Rings was an inspiration for Cameron.

"The photo-realism of facial CG for humanoid characters had to improve significantly.

"Peter Jackson forming Weta and doing the Gollum character in the Lord of the Rings films demonstrated to me that technologically, it could be done. We were going quite significantly beyond what Peter had done with Gollum because we have multiple characters based on different actors.

"Gollum was largely a key-frame, even at that time, even though the performance was based on what Andy Serkis has done.

"By key-frame, I mean that animators actually sit there and animate it. I didn’t want it to be animation. I wanted it to be performance.

"I wanted it to be what the actors did.

"If I showed you what Zoe and  had done, you’d see that it’s exactly what the characters do. These aren’t characters by committee. They’re characters that are performed by the actors. Their body and facial performances are captured."

Cameron, of course, brought his legendary eye for perfectionism to every aspect of production, hiring a linguist to develop the Na'vi language and even helping out when the actors needed a little… physical inspiration.

"He'll throw bits of foam at you. If a tree explodes, instead of me going, 'oooeeer', you think what happens when a tree explodes," laughs Worthington.

"There's a shockwave and the tree explodes, so we can't blow up a tree inside the volume, it's dangerous. But you'll have buckets of foam and a group of us on the sidelines and on action they'd throw all the foam at me. And I'm going to react truthfully. It's all about trying to get these absolute truths in an imaginary circumstance.

"What also happens is you get hit with the shockwave, so Jim would go, 'Hhhm, this ain't working. So we'll throw the debris at you and I'll hit you with a big rubber stick.'

"So as you run past him, he'd belt you with a stick and I'll go flying across the room, but when you watch it back and there's an explosion and my blue alien goes flying, it looks like we've been blown up on a real set. "

Once he'd captured every scene he needed, Cameron could turn his attention to approving the visuals and tweaking the film to his satisfaction. And he also faced the challenge of showing it to eager audiences...

Next: The Long Slog And The Comic-Con Challenge