The city of San Fransokyo at night. Images courtesy of Disney Animation Studios.
The city of San Fransokyo, an architectural portmanteau of Tokyo and San Francisco created for Disney's Big Hero 6, contains 23 separate districts, 82,000 buildings, 400,000 trees and streetlights, a city’s worth of zooming cars, and strolling crowds that add up to about 500 total terabytes of data. “It's a huge, huge environment,” Hank Driskill, the film’s technical supervisor, told The Creators Project. “Geometry-wise, it's bigger than our previous three films combined.”
Driskill and his team took tens of thousands of videos and pictures of buildings, people, and scenery in order to successfully fuse the two megalopolises. “We’re big research folks here, we really like to do our homework,“ he said. “Everything from the way the skies look in those two environments, the way the fog rolls in in San Francisco, to lots of subtle things like, what do alleyways look like in the two cities? What does the graffiti look like on the walls?"
Often plucked brick-for-brick from the real world, San Fransokyo’s massively-detailed digital cityscape is an appropriate backdrop for the Marvel-scale struggle of the young protagonist Hiro Hamada and his friends against a mysterious and powerful masked villain.
A separate challenge manifested itself in the complex crowd dynamics that changed San Fransokyo from a series of buildings into a living, breathing city. Digital people go about their everyday lives in the fictional metropolis, shopping in buildings that might later be smashed in scuffles between characters, good and evil. “I’m really looking forward [to] people being able to get this on Blu-ray and watch in more detail,” Driskill says. “There are a lot of cool subtleties in those shots where there are just thousands of characters on the sidewalks. It's some really great imagery, and it's really, really rich.”
The team also took to the internet to identify leading experimental technologies: 3D printers, highly focused lasers, personal-sized thrusters, nanotechnology, electromagnetism, and more make cameos in the film, each coming from a thoroughly-researched realm of study that contemporary innovators, not unlike Hiro, are working to produce in the real world.
“The idea was that Big Hero 6 was going to take place tomorrow, you know? It was some undefined near-future,” Driskill explains. “We didn’t want it to be some sci-fi film that takes place a thousand years in the future; we wanted it to feel very real and recognizable and grounded, but we wanted to really celebrate some of these things that are on the horizon.” Driskill, for example, spoke to roboticists at Carnegie Mellon, where he encountered the soft robotics experiments that would come to inspire Baymax’s friendly design.
And a physicist was called upon to help create the sequence in which a character enters a theoretical space between entrances to a wormhole. Though the team had a good idea of how they wanted the scene to look, they still had a few problems: “These beautiful, beautiful images came out the other side of them, but the data sets for the wormhole were huge.” What they imagined is a fractal-inspired cloud that would be at home in a Miguel Chevalier installation, but required massive amounts of processing power and disk space to render.
All of these elements, combined with the cinematic textures Big Hero 6's co-directors Chris Williams and Don Hall wanted for the movie’s appearance, added up to a lot of data for the animation programs to process. “We bumped up against the limits of what we were capable of with our existing toolset,” says Driskill.
Luckily, throughout the film’s planning stages, Disney engineers Brent Burley, Chuck Tapin, and Sean Jenkins, members of a special group led by CTO Andy Hendrickson—who's responsible for planning out the next five years of the company’s software innovation—had been developing a rendering program called Hyperion. The program manages light transport, ray tracing, and scene complexity—areas that had proven challenging in the creation of films including Wreck It Ralph and Frozen. Fortuitously, Hyperion came to fruition just as the Big Hero 6 team realized they were going to need a bigger renderer to handle the colossal film.
“The director wanted to pursue a very realistic cinematic look to the movie in terms of the way light bounces around lens distortion, chromatic aberrations, depth of field,” said Driskill. Hyperion was the solution they needed to realize both those stylistic elements and the outrageous complexity of San Fransokyo itself. “Just the ability for an artist to make the whole city at once—instead of making it in lots and lots of layers and putting it all back together—was crazy. We would never have tried that before but Hyperion really let us do that.”
According to Driskill, Big Hero 6 is "orders of magnitude larger" than its predecessors. Compared to Tangled, for example, it took 20 times as long to render, clocking in at 199 million core hours, compared to Tangled’s 1.5 million. The studio’s ability to create a whole world for their characters to live in, and possibly even build on in the future, is a game-changer. “It was the most ambitious thing that we’ve ever chased,” Driskill admitted. “It was the most ambitious thing that I think any facility's really pursued on a film.”
Big Hero 6 is in theaters now. Come for the robots, 3D printing, and lasers, stay for the sweeping vistas and intricate crowd dynamics.