When James Cameron directed “Avatar” in 2009 he innovated performance capture technology that would change filmmaking forever, but by the time he began writing the sequels in 2013 the demands of his story already surpassed what was possible on the original film. In an effort to economize time and money while also creating unity across what will potentially become four sequels, Cameron embarked on a years-long process in which writing, design, and research and development were all taking place at the same time and feeding into each other.
“We started the screenwriting process officially in the summer of 2013,” Cameron told IndieWire. “The next few years were parallel processing on writing four films, designing every creature, every character, every vehicle, every cityscape, every biome, every habitat across those four movies. That same period of time was also for R&D and tech [development] to really future-proof ourselves across that whole oeuvre of films, because I’d rather stop once for a big chunk and get it all ready, and then work with a kind of rhythmic cadence forward from there where we don’t have to stop and retool at each stage of the game.”
That meant a long gestation period for audiences eager to see the continuing adventures of the Na’vi, but if early reactions to “Avatar: The Way of Water” are any indication it was well worth the wait. For Cameron and his team, the biggest challenge was adapting the performance capture techniques of the first film to an underwater setting. Shooting “dry for wet” was never an option, as Cameron wanted the actors to respond to the properties of the water with complete authenticity; that meant figuring out how to achieve performance capture in a tank, which introduced a whole series of complicated problems. In some cases the simplest solution ended up being the correct one, as when the filmmakers realized that bubbles from scuba tanks interfered with the motion capture markers on the actors; after exploring various high-tech options, Cameron opted to simply hire camera operators who were experienced free divers that could hold their breath.
The director found a similarly straightforward method of capturing the actors’ eye movements with the high-definition head rigs that were attached to record every nuance of their expressions. “We didn’t know how we were going to deal with the eyes,” he said. “We didn’t know if it was going to be some kind of mask, or just naked in the water, but we eventually wound up using very, very thin swimmers’ goggles — they’re two bucks a pair. They’re literally the cheapest goggles you can get. All the high-tech ones had curved lenses and nice frames and all that, but these were like two little plastic pill cups and a rubber band, and they worked the best. But it was a year of testing to find out they worked the best.”
20th Century Studios
On the original “Avatar,” the performance capture cameras used infrared light to shoot the actors, something that would not work in the sequel’s underwater locations. “You set up all these cameras in a big grid to shoot the marker suits from different angles and then interpolate in real time a kind of 3D point cloud of where all the actors’ bones are, essentially,” Cameron said. “We use infrared cameras for that, but infrared doesn’t propagate through water at all, so now what are we going to use? We wanted to use something in a non-visual wavelength, so the obvious thing was ultraviolet.”
The problem is that no one had ever used ultraviolet in the way Cameron intended, which meant an extensive period of testing. “We built the cameras, we built the housings for the cameras, we did tests, we learned from the tests, we built an actual production version of the camera with an ultraviolet LED ring that we stood up in a test tank, then we built a bigger test tank. Ultimately, we built our full-on production tank that was 100-feet long and had a big wave machine at one end with the ability to create a 10-knot circulating flow within it.”
One of the most important steps in Cameron’s research and development was taking his entire team to the Bahamas, where they ran tests to determine the movement of the film’s water creatures and how the actors would ride them. “We tested these creature mockups that could be flown around the water at high speed and even pop out of the water and fly over it and then dive back in,” Cameron said. “It sounds kind of impossible, but we built them based on a water jet principle — they were being driven by a high performance jet ski engine.” Based on what the filmmakers learned ergonomically they redesigned the creatures and fine-tuned the riding process, testing how hair, weapons, and other factors would respond to the creatures’ movements in water. “Then we brought it all back into the tank and taught the actors how to do it,” Cameron said. “It was a tremendous amount of trial and error perfecting it and then transferring that knowledge to the stunt people and actors.”
The good news is that now Cameron’s tech is ready for whatever comes in the next three “Avatar” films. “We could probably write a book about how we figured all this stuff out, but the key to it is having a vision of what you want it to look like,” the director said. Even for James Cameron, the vision doesn’t come fully formed. “That vision comes into focus, it’s not crystal clear.” That said, Cameron promises that now that the vision has evolved and the technology has grown to match it, audiences will be thrilled with where the series goes from here. “Trust me, you ain’t seen nothing yet.”