By Iain Blair

Visual effects supervisor Eric Barba and his team of Nelson Sepulveda-Fauser (ILM VFX supervisor), Daniel Macarin (Weta FX VFX supervisor) and Shane Mahan (Legacy Effects co-founder), were Oscar-nominated for their work on Alien: Romulus. Directed by Fede Alvarez, the sci-fi thriller takes the Alien franchise back to its roots. While scavenging the deep ends of a derelict space station, a group of young space colonizers — led by Rain, and her android brother, Andy — come face to face with the most terrifying life form in the universe.

We talked with Barba, who won an Oscar for his work on The Curious Case of Benjamin Button, about the challenges of making the film.

Fede said that Ridley Scott’s original Alien was his inspiration for dealing with everything from the sets to the VFX. How did that play into your approach?
Hearing that he wanted to do as much practically as possible is always helpful for us in visual effects because it means we’re going into the shoot with a plan. That always helps us execute any extension work, adjustments and additions, as well as create the digital versions much more effectively. I was thrilled to hear that. He’s very smart; he pitched what he wanted to do, and he had me come onboard very early to help him do it.

What were the big challenges for you?
Initially, it was figuring out how we were going to shoot the zero-g sequences — those are incredibly challenging from the perspective of the actors, stunts, sets and camera. Then it was trying to get the bodies to feel right and not like they were rotating on rigs. We did a lot of planning and previz for that. This led to four set builds—two vertical and two horizontal — allowing editorial flexibility while keeping the camera team and actors unaware of orientation.

For shooting the live-action elevator sequence with Andy and Rain, imagine a five-story elevator shaft, but instead of being vertical, it’s on its side and has stunt rigging built into it. Even though we’re shooting it as she moves away from us horizontally, ultimately it looks as if she’s flying straight up. We had a smaller, vertical version of that set so that the audience wouldn’t be able to tell which way is up. We shot them in rigs, sometimes horizontal, sometimes vertical, and then cut back and forth between them.

We then added CGI bits on top to help the wind, the sense of motion and things that could float in the air. There are also some full-CG shots in between where we couldn’t shoot with our actors. It was a tricky thing for us, especially where it concerned the Xenomorph. We used everything available to us to achieve the illusion: the vertically and horizontally built sets, stunt rigs, CGI — basically, a combination of all viable techniques to make viewers feel like they are in zero-g.

How did you deal with the character of Rook, who’s a “reanimated” version of Ian Holm’s character in the first film?
We had the most discussions and planning for Rook, which made its creation a major hurdle. We had to figure out how to bring the Ian Holm look-alike back to life. It’s not meant to be Ash from Alien; it’s meant to be off of the same assembly line. This particular science officer has had some adventure with a Xenomorph and has been acid-burned, and he’s malfunctioning and broken, but we wanted it to look like Ash.

We started with the design of a puppet, knowing we would have to replace the face because Fede wanted an animated puppet. But our Ash had to do so much exposition, and he interacts so much and tells so much of the past story that we knew that was going to be a challenge. Initially, we did a kind of 3D replacement, which ultimately led us to a more modern replacement using our puppet and a bit of machine learning, so it was a unique situation. I don’t think it’s ever been done before, using a puppet and animatronic on the day, expounding the exposition that was prerecorded and then ultimately replacing the face with a face derived from the 4K scans of Ian in the first film.

Directing eye movements via machine learning and a headcam was challenging, but once solved, it helped animate the Xenomorph when practical effects — animatronics, a suited actor, and a puppet — weren’t feasible.

How did you deal with the big scenes full of Xenomorphs and Facehuggers?
For a horde of aliens, or the scenes in zero-g where they’re running down walls, we had to create them in CGI; it was the same for the Facehuggers. We had to create a horde of those, as well as the zero-g version of their offspring, which was an amazing creature that the Legacy Effects team created with an actor, and we enhanced that. We also had to create the whole vibe of space from those earlier films. We built our hero ship, the Corbelan, as well as the probe that we see in the initial part of the film, as full miniatures to capture the feel of the original Alien films. I wanted to start with that, so Pro Machina came in and built those for us. We shot probably a half dozen shots with them in front of an LED wall and ultimately put two of them into the film.

The rest of the shots with the ship were done digitally, but all are based on those handcrafted physical models, giving us the feel of those original films. Then we used lots of little tricks and techniques to make the digital shots feel a bit more like a miniature as we rendered and comped them.

Even though you were referring to the look and feel of the original films, you still used new technology. Tell us about the pipeline for this one.
There’s new technology throughout, starting with the analog and what it took to create, say, the Xenomorphs. The sculpting techniques, the material techniques and the way things are built are very different now, and Legacy Effects pointed some of that stuff out to me. There are so many great 3D tools now. They sculpt in 3D and can print stuff out. The animatronics and the way that Rook’s mouth moves — that was all built in CAD, and then the pieces were printed and assembled. The physical teams have embraced a lot of the digital tools to help them with their builds, and because we relied so heavily on the analog, the digital got to stand on those shoulders. I think it created a much more realistic image in the end, and that’s what Fede was after.

Maybe the unique things were how we used machine learning (because that hadn’t been tried before) as well as using a headcam to drive Rook’s performance. That was a whole new thing that Metaphysic AI had to write because they’d never been asked to do that before. Typically, that technology has been used to, say, make actors younger. We saw that in the movie here, but to use one actor to drive another actor and then put it back on the puppet? That was new, and we had to figure out how to do that for a whole lot of shots in the time and budget we had. It took a lot of creative thinking, planning and really intelligent people to pull it off. We worked closely with all the practical teams initially because we had to get all that stuff ready for production.

How many VFX shots were there in the end?
There are 1,400, and there would have been a lot more if we hadn’t had all the practical stuff to shoot. Even some of those shots we enhanced, removing rods, puppets, lines, adding CG tails and so on. Small stuff, but it adds up. I spent two years on it, and I was the first HOD hired. That’s the case on a lot of these movies these days because the VFX supervisor has to come in immediately and start breaking down the movie to make sure that the director’s plan and the studio’s budget meet peacefully. And then you’re there to the very end in the DI with the director, making sure that everything is right as it comes rolling in.

Who did what in terms of the heavy lifting?
Initially, ILM was our primary and was responsible for getting all the CG work going, including the Xenomorph, Facehuggers, probe and Corbelan. ILM also helped me set up the look and feel of space. Then, with less than a year left for post, we brought in Weta FX to help. Weta took on the third act with the offspring as well as the space shots around the station going into the rings. We also had Image Engine, Wylie, Fin Design and Effects, Atomic Arts and Metaphysic doing smaller pieces to help us out.

Where does this rate in terms of creative satisfaction?
At the very top, both technically and artistically. I started out as an artist and designer, so being able to bring my artistic sense to the table and work collaboratively with everybody on this was hugely satisfying.

Industry insider Iain Blair has been interviewing the biggest directors in Hollywood and around the world for years. He is a regular contributor to Variety and has written for such outlets as Reuters, the Chicago Tribune, the Los Angeles Times and the Boston Globe.