In Doctor Strange, Benedict Cumberbatch plays a neurosurgeon who is introduced to the world of alternate dimensions by the Ancient One (Tilda Swinton). Traveling through space and time, he becomes a modern-day wizard, but, says the film's visual effects supervisor Stephane Ceretti, "We didn't want to do the same kind of magic we've seen in the Harry Potter films or other magic films." So the movie's particular challenge became "making aspects of everyday life behave in a different way, in a way that's not natural."
To do that, the film - shot on a $165 million budget, it grossed more than $500 million worldwide in its first two weeks - used 1,450 visual effects shots, which is on the low end for a Marvel film, to create an eye-popping world in which entire cities contort every which way.
For those effects, says Ceretti, "We had to re-create New York and London, very faithfully, fully digital, in the computer." As is typical on a Marvel tentpole, the VFX work was shared by many facilities. Industrial Light + Magic handled the New York sequence, while Luma Pictures was tasked with folding London in on itself.
"When you're re-creating city blocks, you're dealing with huge amounts of digital information, and we needed to be able to manipulate it to make the buildings kaleidoscope and transform," says Luma VFX supervisor Vince Cirelli. "That required a new way of processing the information and newly developed tools that allowed us to take these big blocks of information and manipulate them in a layered approach. We would break up the city, and each building would become its own data set, so we were able to isolate and animate them."
The film also required digital double work that included facial animation. For shots in which Doctor Strange leaves his body, a CG version of Cumberbatch was created using performance-capture footage of the actor.
Cumberbatch's face also was used to create Doctor Strange's nemesis Dormammu. Says Ceretti of Dormammu's mug: "That was an homage to the Doctor Strange comics from the '70s. We wanted to be as faithful to the material as possible."
This story first appeared in the Dec. 2 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.