How The 'Avatar' Sequels Shoot Underwater Mo-Cap According To James Cameron

Avatar 2 will finally hit movie theaters in 2020, 11 years after the first Avatar was released in 2009 and three years after the great SNL sketch poking fun at Avatar's font. The primary reason for the decade-long delay? The technology required to film director James Cameron's ambitious vision of a world submerged in water didn't quite exist yet. So they invented it.

Cameron had been hinting for years about his grand plan to set the Avatar sequels primarily underwater, and shoot them using underwater motion-capture technology — but no one quite believed him until shooting for all four (!) sequels finally went underway this fall. Now that Cameron is in the full swing of production for Avatars 2 and 3, he can give us the scoop on what it's like to shoot with this newfangled technology. Long story short: it's really hard.

In an interview with Collider, Cameron (sounding somewhat exhausted himself) described the exhaustive process that went into perfecting the Avatar sequels underwater motion capture technology:

"Well, we're doing it. It's never been done before and it's very tricky because our motion capture system, like most motion capture systems, is what they call optical base, meaning that it uses markers that are photographed with hundreds of cameras. The problem with water is not the underwater part, but the interface between the air and the water, which forms a moving mirror. That moving mirror reflects all the dots and markers, and it creates a bunch of false markers. It's a little bit like a fighter plane dumping a bunch of chaff to confuse the radar system of a missile. It creates thousands of false targets, so we've had to figure out how to get around that problem, which we did. Basically, whenever you add water to any problem, it just gets ten times harder. So, we've thrown a lot of horsepower, innovation, imagination and new technology at the problem, and it's taken us about a year and a half now to work out how we're going to do it."

Cameron and crew have done several test runs with the technology, but apparently the only successful run they had was in the first week. But the scale of underwater scenes in the first sequel will only pale in comparison to the second and third sequel, which Cameron notes will be the most underwater-heavy installments.

"We've done a tremendous amount of testing, and we did it successfully, for the first time, just last Tuesday [November 14th]. We actually played an entire scene underwater with our young cast. We've got six teenagers and one seven-year-old, and they're all playing a scene underwater. We've been training them for six months now, with how to hold their breath, and they're all up in the two to four minute range. They're all perfectly capable of acting underwater, very calmly while holding their breath. We're not doing any of this on scuba. And we're getting really good data, beautiful character motion and great facial performance capture. We've basically cracked the code."

The Avatar sequels' new young cast of unknowns were announced earlier this year, and seem to be living up to the expectations held for this big-budget blockbuster. Luckily the arduous production schedule of the first two Avatar sequels that require these young actors to act underwater without scuba gear (!) won't be unreasonable — Avatar 2 and 3 are filming simultaneously before Cameron takes a break to finish post-production on the films before going back in to shoot Avatar 4 and 5 simultaneously.

Avatar 2 will hit theaters on December 18, 2020, followed by Avatar 3 on December 17, 2021; then Avatar 4 on December 20, 2024; and finally Avatar 5 on December 19, 2025.