New Yorker - "How Perfectly Can Reality Be Simulated?"
By Anna Wiener
"Yet certain things remain hard to simulate. There are multiple types of water renderers—an ocean demands a kind of simulation different from that of a river or a swimming pool—but buoyancy is challenging, as are waves and currents. “The Navier-Stokes equation for fluid simulation is one of the remaining six Millennium Prize Problems in mathematics—it’s unsolved,” Vladimir Mastilović, Epic’s vice-president of digital-humans technology, told me, referring to a set of math problems that have been impervious to human effort. Clouds are tricky. Fabric, which stretches, bends, wrinkles, and billows, often in unpredictable ways, is notoriously difficult to get right. It’s hard to simulate chain reactions. “If I chop down a tree in a forest, there’s a chance that it hits another tree and knocks over another tree, and that splinters and breaks,” Kim Libreri, Epic’s chief technology officer, said. “Getting that level of simulation is very, very hard right now.” Even the smallest human gestures can be headaches. “Putting your hand through your hair—that’s an unbelievably complicated problem to solve,” Libreri said. “We have physics simulation to make it wobble and stuff, but it’s almost at the molecular level.” (In some games, hair is simulated by using cloth sheets with hairlike texture.)
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Mastilović suggested that MetaHumans could one day be used to create autonomous characters. “So it will not be a set of prerecorded animations—it will be a simulation of somebody’s personality,” he said. He suggested that a simulation of Dwayne (the Rock) Johnson could be fun, and that people could create digital copies of themselves and then license and monetize them. Mastilović’s team often talked about a concept called Magic Mirror: a way to visualize, alter, and explore oneself virtually. “What if I was ten kilos more, ten kilos less?” he said. “What if I was more confident? What if I was older or younger? How would this look on me?” He added, “When things become truly real, photo-real, and truly interactive, that is so much more than the medium we have right now. That’s not a game. That’s a simulation of alternate reality.”
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In the past decade, Sweeney has become one of the largest private landowners in North Carolina, buying up thousands of acres for conservation. Land conservation struck me as an interesting project for someone in the business of immersive indoor entertainment—incongruous enough that I found it kind of moving. (In a 2007 MTV documentary, Sweeney showed off his garnet collection, some of which was acquired on eBay, and a “climbing tree” in his yard.) When we spoke, I asked Sweeney whether working in games had made him see nature differently. “Natural scenes tend to be the hardest to simulate,” he said. “When you’re standing on a mountaintop, looking out into the distance, you’re seeing the effect of trillions of leaves of trees. In the aggregate, they don’t behave as ordinary solid objects. At a certain distance, trees become sort of transparent. When you look at the real world and see all the areas where computer graphics are falling short of the real world, you tend to realize we have a lot of work yet to do.” He speculated that an efficient, realistic simulation of a forest would require a “geology simulator” and an “ecology simulator,” each with its own complex sets of rules.
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My friend and I talked about Big Basin, a state park that was home to some of California’s oldest redwoods. A few years ago, it suffered a terrible wildfire. I toured the park shortly after the fires, and found it devastating. But the trees were now trucking along. There was an archival impulse to scanning that I found appealing, even as I wondered if there was an anxiety to it, too. Was there something bleak about creating virtual facsimiles of the natural world while we as a species were in the process of destroying it? Lind, the Quixel co-founder, told me that he had gone on a scanning trip to Malibu in 2018. His team spent a week scanning the Santa Monica Mountains, capturing the texture of the landscape. Two weeks later, the Woolsey fire burned almost a hundred thousand acres of land in the area. “That was actually fairly emotional,” Lind said. “Every scanning expedition, you develop a certain connection with that place.” Still, they had the scans. Today, those images could be scattered across games and movies, in jumbled pastiches of the real thing."
