Visual effects supervisor Nelson Sepulveda-Fauser discusses the collaborative effort to make Alien fans scream once more.By Dan Brooks(Credit: 20th Century Studios)Nelson Sepulveda-Fauser remembers it well. It was summer 1979. He was 12 years old. Two years prior, Star Wars: A New HopeAlien and he was dying to see it, though he was too young to buy a ticket and his parents refused to take him. As such, Sepulveda-Fauser did what any underage cinema-obsessed kid would: he snuck in to see it at Los Angeles vaunted Egyptian Theatre.I remember the impact that it had on me, he tells ILM.com. It was the first movie that I saw where I said, Oh my God, thats what a real alien movie is about.Cut to 2024, and Sepulveda-Fauser is now a visual effects supervisor at Industrial Light & Magic, having led the companys Sydney studio in work on Alien: Romulus. For him, Alien will always be about the feeling of Ridley Scotts original film and, thankfully, Alien: Romulus director Fede lvarez thought the same.When Fede described his idea of making it like the original, it was just one of those realizations where its like, man, I get to recreate that childhood moment, in a way, Sepulveda-Fauser says. The result was a 40-year full circle for me.Alien: Romulus arrived in theaters August 16 and quickly became a bona-fide box-office hit; as the movie continued its impressive run, Sepulveda-Fauser spoke with ILM.com about his approach to Romulus visual effects and the secrets behind some of its most memorable sequences.Concept art by Amy Beth Christenson (Credit: ILM & 20th Century Studios)Back to basicsThe seventh film in the Alien series, Alien: Romulus takes place between the events of the original film and Aliens (1986), and follows a group of young Weyland-Yutani colony workers eager to abscond to a better life. At the heart of Alien: Romulus are Rain (Cailee Spaeny) and her adopted brother, Andy (David Jonsson), who just happens to be a kind-hearted but damaged robot. A chance at escape leads the crew to an abandoned spacecraft, but instead of freedom they find unexpected terrors including our old friend, the xenomorph.Romulus leans into the series horror roots and, from the beginning, lvarez and Sepulveda-Fauser were in alignment on how it all should look.From the get-go, from the day that I met him, one of the very first things that he said was, I dont want this thing to feel CG. I want this creature to feel real. If it doesnt feel real, its not going to be scary. So the goal was to get as many practical elements in camera as we could. Everything else that we needed to build in computer graphics had to work around that, and integrate into photography seamlessly. This would be a stark contrast to 2017s Alien: Covenant, the last film in the series, which relied heavily on digital effects and creatures. For Romulus, Legacy Effects was on board to handle the practical elements, with ILM and Weta FX creating the visual effects for various sequences.Director Fede lvarez. Photo by Murray Close. (Credit: 20th Century Studios)Under this ethos, the main challenge for Sepulveda-Fauser, as well as production visual effects supervisor Eric Barba, was matching ILMs visual effects to Legacys practical work; if they were successful, audiences would not be able to tell where one stopped and the other started. This includes not just creatures, but sets and starships. lvarez had the model shop create miniatures of the Corbelan ship, research center, and the EV, which Sepulveda-Fauser used to create digital replicas for the movie. The tricky part was keeping the character of a practical model in the close-ups, he notes.First and foremost, however, was bringing the xenomorph back to life.Bigger ChapWhen it came to realizing the xenomorph, Alien: Romulus used just about every trick in the book. There was a man-in-a-suit version, a bunraku puppet, and an electronic build. Scenes requiring more fluid movement, however, meant ILM would have to work its magic.The Legacy puppets are beautiful up close. They hold up really well. But as soon as we have to incorporate specific body movements, we have to jump in with visual effects, Sepulveda-Fauser says. When the xenomorph is in motion, we cant get a practical creature of that size to perform some of the movements required for an action sequence. In the elevator shaft sequence, for example, when hes getting shot or when he catches Rain or hes coming toward her, those scenes are a blend of our wide and medium close-ups with practical effects. We had to match the xenomorph model perfectly so we could have closeups cut between practical and CG.(Credit: 20th Century Studios)Still, Sepulveda-Fauser and his team took care not to overdo it, always looking at the original Big Chap, as the xenomorph was called during production of Alien, as a guide, as well as those in James Camerons Aliens for reference.Fede always said, I want this alien to be creepy. He didnt want over-exaggerated motion on the creature, Sepulveda-Fauser explains. His concern was that as soon as it moves too much or too fast, we take the audience out of the movie. We start feeling that CG on the screen. He wanted creepier movements. Thats why theres the slow crawling on the walls. The slower movements make it feel creepier, strange. The creature is doing something impossible its crawling on a wall yet we had to make it feel possible, ominous, and weird.Ultimately, having Legacys new builds proved to be the best reference.I mean, seeing a practical creature on set is inspiring. Youre seeing it under real, live conditions and in real action, he says. You see it and think, We know exactly what this xeno needs to look like, and we did. We replicated it as faithfully as we could to a real living creature.Facehugger strollOne of the more tense sequences of Alien: Romulus finds Rain, Andy, and friends tip-toeing through a frigid corridor, hoping to avoid the attention of the crafts resident Facehuggers. Throughout, the creepy crawlies move slowly, tapping their finger-like appendages, before finally becoming alert to their guests presence and launching a spine-tingling attack.Thats funny, because that sequence was shot in a couple of different spots, Sepulveda-Fauser notes. I shot a lot of that second unit, and that was in conjunction with some puppet work for the Facehuggers. There were Facehuggers that were set up in crates by the Weta puppeteers and the actors performed through the rest of the set imagining the CG huggers that we would fill in. When you look at that sequence, its a combination of, again, jumping from practicals to all CG. The Facehugger was another creature that we had to match absolutely perfectly.Animating the Facehuggers is one case where ILM broke a bit from the original films, feeling the creatures could use a bit more fluidity to satisfy Fedes vision.In some cases when we saw that action of the Facehugger on set, it was obvious that it was a puppet. Although that was desirable in many cases, after a while the director realized this sequence was not going to be super exciting with things on wheels rolling along chasing these guys, Sepulveda-Fauser says. So we had to work out different Hugger run cycles for the chase. That took some time and experimentation, because it needed to both look like a mechanical thing, so it could pass as practical, and also it needed to follow this very specific action that the director wanted. We went through tons and tons of experimentation on how to make that work and, finally, we landed on something that Fede was really happy with, because they still look like they could be animatronic. We always kept it to some grounded reality.The x-rayFeatured prominently in the movies trailer is a particularly disturbing scene: the crews pilot, Navarro, uses an x-ray wand to scan her own chest, and finds something alive inside. Its a clever spin on the series classic chestburster scenes of old and, to work, it had to look both believable and creepy.When the creature guys came on to do the chestburster, everybody was really excited because they were doing tests on the side and it was the first time we were seeing something so iconic to Alien in a scene, recalls Sepulveda-Fauser. It was a good feeling, Were going to do it like they did in the original. When Fede came up with the idea of the x-ray, it was even more exciting because weve never seen what this looks like from the inside. How exactly do we do that? So we digitally-built all of Navarros skeletal, muscular, circulatory structure, as well as organs. We researched the look of an x-ray, and we worked up the ideas in compositing, with animation to match the original puppet, broke some ribs, and popped it through. It was a quick moment but pretty neat.Considering its heavy use in promoting Alien: Romulus, I submit to Sepulveda-Fauser that this scene played a large role in getting fans new and old excited for the movie.It was a new take on the chestbuster and he made it terrifying in a different way, Sepulveda-Fauser says. I remember the original movie. You didnt know what was going to happen, then all of a sudden, blam! This guys on the table and the alien pops out of his chest and everybody in the audience goes bonkers. You couldnt do that again. If you recreate it, its not going to be as effective. So setting it up with Navarro, again feeling sick, you kind of know whats going to happen, but you actually dont know whats going to happen. The reveal of the creature from the inside was a great idea. That was the scary moment. Understanding this thing is ready to pop out. We werent repeating the original, were scaring you in a slightly different way, and I thought that was really cool.Zero-G journeyIn a movie filled with action set pieces, this might be the standout. Following a shootout with a xenomorph swarm, Rain must navigate from one end of a hall to another all in zero gravity while the creatures acid blood floats dangerously around her. Initially, however, it was meant to be a much smaller sequence.That was an interesting one because Fede had a really specific idea of what he wanted, explains Sepulveda-Fauser. In the beginning when we were first understanding the effect, it was a lot more subdued. It was going to be some alien blood in zero-g. But its a big action sequence and Rains had this big fight. There was a lot going on. The acid effect needed to have more character and quickly developed into, No, the acid is an actor in this scene. This is a very, very scary moment. Its got to be something else, it needs to be frightening, turbulent, its got to be an immediate danger that they cant pass. And it needs to perform with intensity and visual impact.To achieve the intensity of the redesigned sequence, Sepulveda-Fausers Sydney team worked closely with ILMs San Francisco studio.We worked hard with the team in San Francisco to put all this together, he says. There were a lot of requirements there. We were in zero-g, it needed to be terrifying, it needed to come toward our actors, to look impassable, but they still needed to be able to somehow make it through. We also needed a moving air current to affect the acid swirling in zero-g. So there was a lot of choreography needed. It took a lot of development and experimentation to get the recipe for realism so that it didnt feel magical as in a Harry Potter movie. It was easy to go into a fantasy world really quick with this effect. We finally came to a setup that I believe was successful, so that it sold the idea that this was possible as kind of a funnel of real acid happening within the set.Signing offThanks to the success of Alien: Romulus, now the highest-grossing horror film of the year, the future seems bright for the xenomorph and our favorite space horror franchise. Though its gratifying for Sepulveda-Fauser, the reward is in the work on-screen.It makes me really proud to say that the Sydney team put this together, Sepulveda-Fauser concludes. Im a little older now. Ive been at ILM for 20 years and in the industry for 30-plus years. A lot of the people that I worked with are of course a bit younger and very, very excited about what we do. To see that new generation of talent embracing traditional methods of filmmaking and adding to it is inspiring. This was one of those shows where youre looking back at film history, looking back at a historic movie, and having to produce something new that still touches back to that with fidelity. This team really put in a thousand percent to make that happen. We achieved something memorable, hopefully for the audiences but even more so for us as big fans. It was a difficult task and it was an easy thing to not get right. But the crew got it right. They worked so hard and put so much care and love into it, that it worked. I really am proud of this work. Its likely one of the best projects that Ive ever worked on.Dan Brooks is a writer who loves movies, comics, video games, and sports. A member of the Lucasfilm Online team for over a decade, Dan served as senior editor of both StarWars.com and Lucasfilm.com, and is a co-author of DK Publishings Star Wars Encyclopedia. Follow him on Instagram at @therealdanbrooks and X at @dan_brooks.