Spoilers for Doctor Strange below.
Opinions about the plot, characterization, and racial politics of Doctor Strange have been mixed, but one point has been more or less unanimous among critics: It’s freaking gorgeous. As we here at Vulture have said, the CGI in Marvel's latest are among the best of any film in the past 15 years, seamlessly merging human figures with reality-warping landscapes and objects that feel hallucinogenic without looking hokey. Cityscapes fold in on themselves while heroes and villains slide along skyscraper walls; miniature wormholes open up, taking people from one gravitational locus to another. Though Benedict Cumberbatch may be playing the titular mage, the wizard at the postproduction keyboard was visual-effects supervisor Stephane Ceretti.
When the Frenchman began his work on Strange, back in 2014, he was fresh off of another Marvel victory, having supervised the Oscar-nominated VFX in Guardians of the Galaxy. This time around, he and director Scott Derrickson had the challenge of making Strange's spell-casting seem simultaneously surreal and tactile. “The main driving thing for Scott was technically to try and make the magic physical in some ways,” Ceretti recalls. “That's why, for example, when they open portals, it looks like they’re made of real sparks, but they behave in a different way than you’re used to seeing them. The buildings that you're distorting, they're made of material that we know, but they behave in a different way.”
In order to achieve that grounded feel, Derrickson and Ceretti looked for inspiration from a motley assortment of visual reference points. He says they analyzed the physical impossibilities of M.C. Escher’s drawings, the forced-perspective motion of the mobile game Monument Valley (which, you may remember, also served as inspiration for Frank Underwood), the unnatural realism of light-painting photography, and the mathematical psychedelia of fractals.
Speaking of fractals, Ceretti was surprised and impressed to find things that looked like them in the pencil-and-ink artwork of comics writer/artist Steve Ditko, who co-created Doctor Strange in 1963: “[Ditko’s] use of colors and shapes was pretty uncommon at the time,” he says. “And actually, today, we can only do those things on the computer. Even some of the design that he did looked like fractals, which were not even invented at the time.”
Of course, they also looked at Inception. But while viewers have remarked upon the similarities between Strange and Christopher Nolan’s building-bending 2009 film, Ceretti says he and his cohort weren’t as reliant on it as you might think. “Obviously, when I read the script the first time, it came up,” he says. “But we didn't look too much at it. We just looked at it a couple times. We all knew the film very well. We thought there were tons of good ideas in it, but there's also other stuff in the comics that's raising the same ideas, and we're still trying to push it further.”
In order to achieve that goal, Ceretti’s team sought to marry the ideas in Inception with the rhythms of an action movie. “Everything that we're doing has to be motivated by the action of the people and why they’re chasing across a city,” he says. “We looked at [Inception], but we kind of elaborated from it and we wanted to make it 10,000 times more dynamic and use it on a much bigger scale, too.”
Cities were not the only raw material for him to work from: The film also features a trip into the so-called Dark Dimension, which looks a bit like a neon-colored asteroid belt. For that scene, Ceretti turned to a decidedly low-art reference. “There's a black-light poster that was inspired by Steve Ditko that was actually in Scott's office,” he remembers with a chuckle. “He had it on top of his desk. If you light it with black light, it all becomes very neon-y. Scott was very adamant that for the Dark Dimension, we go really crazy about the color palette.”
But that climactic and immersive backdrop wasn’t the hardest visual hurdle to leap. Ceretti says the toughest mystical nut to crack was a surreal sequence the cast and crew called the “Magical Mystery Tour” (goo goo g’joob), in which Tilda Swinton’s supremely powerful Ancient One knocks Strange’s spirit — or “astral form,” as it’s known in the film — on a journey to the farthest reaches of reality. “It took many, many months to make it work and find the right balance between the effects and the storytelling, and finding the right length and the right rhythm and the right visuals,” he recalls. “We had a motion-control camera with a motion-control rig to kind of put Benedict into the story and film the elements that we needed for him.”
Their initial cut of the Magical Mystery Tour was seven minutes long, but the finished movie only features about 180 seconds of it. Was Ceretti frustrated at all to see something he spent months on sliced down to such a brief little blip? “No,” he says, firmly. “We're here to serve the film. I think seven minutes would've been too much, and I think it's just the right length right now. It's a glimpse into what's coming into the film, but you don't want to show too much and you don't want to be too crazy for too long at that point in the film.”
Ceretti went to great lengths to make sure his effects were never flashier than he thought they absolutely needed to be. Case in point: a beautifully quiet moment near the movie’s end, in which the astral forms of Strange and the Ancient One hover near a window in New York City, gazing at the East River while time slows to an unnatural crawl and lightning crackles at an eerily mellow pace. They contemplated going wild there, but opted instead for “something very simple, because we didn't want to take the audience away from that moment.”
That decision is consistent with Marvel’s overall visual philosophy, according to Ceretti. “The first philosophy is to serve the story, really,” he says. “We're just setting the right amount of effects at the right time. Sometimes, we went too far and we backed down. Sometimes, we went completely crazy because we knew that we could.” Along those lines, Ceretti’s happy to get acclaim, but he doesn’t want people to pay too much attention to his handiwork. “It's not so much a technological limitation that we have,” he says. “It's more of trying to make sense of what we are doing so that we're not taking over.”