Reviewer talks to graphic renderer from second “Avatar” movie

*Editor’s note: responses have been edited for length and clarity.*

I often write movie reviews from an external standpoint. I am no expert in visual logistics; instead, I can only respond to a film how I experience it, often focusing on my sensory reactions. Yet, when I came into contact with New Zealand native Alan Chambers, I was given an opportunity to understand film from an internal stance.

Chambers was hired to work on James Cameron’s 2022 film “Avatar: The Way of Water” in 2013 by the Weta company and is listed in the credits under “rendering.” He left the production in 2020 to work for Apple in the U.S. as a Senior Rendering Programmer, where he contributes to the development of Vision Pro, Apple’s upcoming mixed-reality headset. He has an extensive background in graphics, including experience in software engineering and video game programming.

Plus, he’s met movie production rockstars like Jon Landau, who produced both “Avatar” movies and “Titanic.”

**AK**: Hi, it’s so nice to meet you. My name’s Amelia. I’m a writer and editor for “The Record,” a college newspaper in central Minnesota. I review movies, so when I heard that you were listed in the credits of the last Avatar film, I knew I had to pick your brain. To start off, can you describe your role within Avatar 2? What sort of duties did you have?

**AC**: Yeah, so I was the lead of real-time rendering at Weta Digital. I was in charge of developing the graphics software toolkit that they would use on stage and during production, which was a critical part of the movie-making process. You’ve got green screens that people have to act against on set and generally when the directors are trying to set up actors to do their thing on stage, it’s difficult for the director to tell them where to look if they don’t have a background. They also don’t know how lighting will affect the look of the actors in particular situations. So basically, the software that I wrote allowed the directors to see live what the final movie might look like—they can use it to change all the lights and background and scenery on set while the actors are still there.

**AK**: What’s the benefit of that?

**AC**: It gave the director a lot of control to make decisions in the moment. Otherwise, they’d do their thing, send it off to production, and have to wait until they got results back before they could see something. And then they’d be like, “OK, we need to reshoot this whole scene because it didn’t really come out like I wanted it to.”

**AK**: How does that connect with CGI, knowing that Avatar is based almost entirely on graphics?

**AC**: We use a process called composition where we composite the real footage on top of the artistically generated imagery. We have to do it in a way that looks plausible and not fake. “Avatar” was a bit different in certain scenes, where the characters as well as the scene were completely computer generated. So in some sense, it’s a little bit easier because you don’t have to bother with the composition. The whole thing is just a virtual scene that gets rendered. But in other senses, it’s kind of more difficult because then when you’re rendering characters, the skin and behavior of the eyes and hair and all this stuff has to be rendered to high resolution; there’s so much detail. So in some senses it was easier than other films, and in some senses it was harder. And there was a lot of new technology that went into Avatar that has never been done before, especially stuff with bioluminescence and water.

**AK**: Do you feel that you’ve gained any unique skills from your time working with the movie?

**AC**: I did develop a lot of really cool skills—mainly on a computer science level, but also from a production standpoint. I learned to be very pragmatic with things. You want to do the best quality feature work or the best quality bug fix, but sometimes you need to be a bit more strategic with things. It might take two weeks to do it properly, or you can fix it in half a day.

These are fairly unique to film because with video games, you tend to have a schedule. But movie-making’s a bit different: people are using things live on set, and they need different features, very ad hoc. You’ve got to drop what you’re doing and jump onto things. The context switch was massive.

**AK**: Makes sense. I just have one more question. As I said before, I write movie reviews. I don’t want to go into videography or anything like that, I’m more interested in the written arts… but what I love about movies is the feeling you get after you’re done watching one. I was going to ask why you, personally, think film as a medium is important?

**AC**: Hm. Stepping back a little bit, just looking at, say, books. When you read through a book, you build up your own imagination of exactly what’s happening, right? There’s a creative process there but it’s personal, and it’s very unique to yourself. And film is obviously a director’s kind of interpretation of a particular story. But for why I think it’s important…

For humans, the visual system is the strongest in sensory perception. I think in that basis, being able to project and stimulate that system is pretty important to people’s happiness. And having a director that is able to do that and create content, it opens people’s minds. There’s unimaginable worlds, planets, people, like in Star Wars—you can see things that you would never ordinarily be able to see. It stimulates that sensory system in a way that books, or any other medium, can’t do. It can take you to places that you would never be able to go, and I just think there’s something quite magical about that.