The Art Of Avatar, designer Steve Messing actually visited China and traveled around photographing mountains there to get photoreferences for Pandora's floating mountains.
Designer Dylan Cole says the team looked at "many different types of mountains, but mainly the karst limestone formations in China. There were three main regions, Guilin, Huangshan and Zhang Jia Jie. Other locations were the Tepuis in Venezuela as well as the karst formations in Thailand. It was about finding that nice balance between rock and vegetation. For a lot of the jungle over views, I used photos that I had taken from the Kuranda Skyrail near Cairns, Australia."
One idea that really didn't make it into the movie is that these mountains are drifting like boats in the water. There was talk about having them collide and have bits crumble away. I think it would have been a great way of showing the power and the danger of the place. Hopefully in the sequel!
How do you convey that the mountains are floating though? Cameron wanted some shots approaching the floating mountains and the banshee "rookery" from above, so Cole and Messing worked on some test shots — one of which became an actual shot in the film. But when you see the floating mountains from above, how can you tell they're not touching the ground?
Explains Cole, "the best way to show that they are floating is by having a nice sense of atmosphere or a cloud between the mountain and the ground." Messing and Cole also worked on a giant 360-degree panorama of the entire floating mountain region. Cameron used this in the "virtual sets" when he was doing his motion capture filming, and it also served as a "style guide" for the film's visual effects, says Cole.
With so many weird colors on Pandora, it's kind of striking that most of the vegetation on the planet is just regular Earth green — except at night, when things start bioluminescing, of course. And Cole admits that "for a long time Jim really wanted all of the vegetation to be cyan instead of green. In fact, most of my paintings have cyan plants." There's just one problem with this idea: Cyan is very close to blue, which is often used to show atmosphere and depth. Cyan-colored plants "made it really difficult to have a nice falloff into the distance. Our images tended to look monochromatic because of it, as well as cold, because there were none of the rich yellows that come with green vegetation. The other idea is that psychologically we associate green with life here on our planet. The themes of life and nature were very important to Jim, so I think he realized green would be a better choice. There are still many wild colored plants, but the overall sense is green."