Avatar: The Game Changer
"And somebody as mind-expanding and pragmatic as Joe [Letteri] has to be able to see it and put it into a system. And I remember when he said early on that we're going to have to grow these forests. And it wasn't a matter of creating layers of things that looked like forests. But to actually grow an environment so that it could be evocative of life. It's the thing that I found that would enhance your movie."
Indeed, for Letteri and the entire Weta Digital team, Avatar exceeds Lord of the Rings and King Kong in both complexity and achievement. In fact, Weta worked on 1,800 out of approximately 2,200 shots. But the experience transcends mere shot count.
"We made low-resolution models of everything for the stage," Letteri says. "In cases where we were far enough along to have high-resolution models, we down res'd those and prepped those for the stage, textured them up and made sure there was a back and forth so that whatever we were sending them would work on the stage: made sure the rigging worked for the MoCap system and for our animation system; if we were updating a model, we'd send it to them; if they needed to make any changes on the stage for rigging purposes, they'd send them to us. It was a pretty good workflow.
"Jim, of course, would capture everything and then go back and do his cameras on it and put together what he called templates, which are MotionBuilder renders run back out in realtime, but played back through the cameras that he had captured, and that's what he used for editing."
Letteri echoes that this whole new virtual system was a real director-centric breakthrough. "It's no longer the director saying, 'Give me something that looks like this.' It's Jim picking up the camera and saying, 'Here's my shot; now you guys take it and make it look real.'
"For Avatar, we had seven main and 14 secondary speaking parts. And we had to turn that into 200 or so for the Na'vi clan, who don't speak but who are still very expressive. It required a whole new level of building characters and environments. The trick for the land creatures was working out a believable six-legged walk and run cycle and the flying creatures had four wings, so we had to figure out how to make them fly without the wings getting in the way."
According to Andrew Jones, the animation director, there was a lot of R&D "figuring out the best model type and most resolution to pack in there and really get the rig to behave well and still not be too slow for animators. The facial rig was within Maya but with plug-ins. We had hoped for a full muscle-based system but wound up going for a blend-shape system but using muscles as the basis for the controls. At any one time, we could swap in a muscle system and see what it looked like, but any of the blend-shapes went much faster."