How Avatar: The Way Of Water pushes CGI boundaries all over again

It has been 13 years since James Cameron’s Avatar (2009) took us on a journey to Pandora’s dreamland. At the time of its release, the movie wowed audiences with a visual spectacle of CGI and became a record-breaking box office sensation (it's taken £2.43bn and counting).

Its sequel Avatar: The Way of the Water — in cinemas and IMAX in 3D from 16 December — also promises to break new ground in the world of VFX, but before we get to the sequel, let's remind ourselves what made the original so revolutionary.

Uncharted territory

James Cameron wrote his first treatment for Avatar in 1994, but the story sat untouched for 11 years until the technology had caught up with Cameron’s ambitious otherworldly vision. By 2005, motion-capture and character facial technology was advanced enough to start shooting, with Peter Jackson’s Wētā FX doing most of the heavy lifting. This, however, was not enough for Cameron and visual effects supervisor Joe Letteri who explored uncharted territory in virtual production.

Read more: Everything we know about Avatar: The Way of Water

Peter Jackson’s Gollum in Lord of the Rings (2001-2003) and Kong in King Kong (2005) came to life by mixing virtual images with live action. Behind these CG creatures — their movements and facial expressions — were actors who wore performance capture suits and hundreds of facial markers. These techniques breathed a human quality into Kong and Gollum, allowing audiences to empathise with them.

Pushing this a step further, Cameron developed image-based facial performance capture. Unlike facial markers, his technology did not rely on hundreds of spherical markers glued to the actor’s face. Instead, a head rig was placed on the actor with a small camera attached to a boom which tracked every minute facial expression. The visual information was then synced to the CG character.

Cameron also incorporated a real-time virtual camera in a huge performance capture 'volume' that allowed him to direct computer-generated scenes as he would live action.

In an interview with Motion Capture Society, he explained how it works: “I can see my actors performing as their [CG] characters, in real-time, and I can move my camera to adjust to their performances.”

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This enabled him and the actors to immerse themselves in the virtual scenes while filming.

Beneath the waves

As the title suggests, Avatar: The Way of Water will dive into Pandora’s oceans. Still an ambitious visionary, Cameron aims for his CG water to exceed anything previously achieved in cinema. Snapshots of the movie’s stunning underwater sequences suggest that he will not disappoint.

In a reaction video as part of their "VFX Artists React" series, the artists at Corridor Crew were baffled by the detail in the trailer’s close-up shots of water. “I don't remember ever seeing surface tension on that complex and dynamic of a scale,” said Ian Hubert.

Read more: Avatar 2 images show huge practical sets

Decades of filming the deep blue have refined Cameron’s techniques. It should not come as a surprise that Cameron is something of a water-enthusiast.

Watch a new trailer for Avatar: The Way of the Water

His underwater debut, The Abyss (1989), was inspired by his childhood love of scuba diving. But why dive alone when you can convince a whole film crew to come along? Everyone on the set of The Abyss became scuba-certified to shoot underwater scenes in an abandoned nuclear plant that Cameron had filled with millions of gallons of water.

He explained the vision behind this “logistically boggling” production in Under Pressure: The Making of The Abyss: “If I couldn't do what 2001: A Space Odyssey did for science fiction films taking place in space, if I didn't feel that I could do that in the underwater arena, then I didn't want to make the movie.”

In many ways, Avatar 2 is an extension of that project. Like The Abyss, much of it was filmed underwater, in a 900,000-water tank capable of imitating ocean currents. The actors were trained to free dive — holding their breath minutes at a time — but instead of wearing deep suits, they wore the familiar motion capture suits and head rigs from the first Avatar.

This technique, known as underwater motion capture, sets the movie apart in the 'underwater arena' of moviemaking.

Most directors, including James Wan in his most recent film, Aquaman and the Lost Kingdom (2022), use the ‘dry for wet’ method. Rather than filming the actors in water, they are suspended on wires to give the impression of swimming. The convenience of ‘dry for wet’ costs the more realistic lighting effects and physics of underwater motion capture.

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Upon finishing the first Avatar, Cameron had hinted at what was to come. In an interview with Extra TV, Sam Worthington, the actor playing Jake Sully, recalls him saying: “I want to continue the story, I’ve got a lot more to tell in Pandora.”

With a never-ending pursuit to perfection, Cameron is expected to push innovation through to Avatar 3 and 4.

Avatar: The Way of Water arrives in cinemas and IMAX in 3D from 16 December.

Watch a trailer below.