Epic's answer to John Carmack, Unreal Engine mastermind Tim Sweeney, says videogames are only '10-15 years' away from photo realism.
Speaking in an interview with Gamasutra, Sweeney said "we're only about a factor of a thousand" away from perfect graphical realism - but we might see it happen in as soon as a decade.
"We'll certainly see that happen in our lifetimes," he said. "It's just a result of Moore's Law. Probably 10-15 years for that stuff, which isn't far at all. Which is scary.
"But there's another problem in graphics that's not as easily solvable," he continued. "It's anything that requires simulating human intelligence or behaviour: animation, character movement, interaction with characters, and conversations with characters. They're really cheesy in games now.
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"A state-of-the-art game like the latest Half-Life expansion from Valve, Gears of War, or Bungie's stuff is extraordinarily unrealistic compared to a human actor in a human movie, just because of the really fine nuances of human behaviour.
"We simulate character facial animation using tens of bones and facial controls, but in the body, you have thousands. It turns out we've evolved to recognize those things with extraordinary detail, so we're far short of being able to simulate that.
"And unfortunately, all of that's not just a matter of computational power, because if we had infinitely fast computers now, we still wouldn't be able to solve that, because we just don't have the algorithms; we don't know how the brain works or how to simulate it."
The tech man said game developers would first have to "simulate the brain and nervous system" in a computer before they could create a truly realistic game. In that case, is there any chance of seeing a really "photo-realistic" game in our lifetimes?