A couple of years ago, Epic Games founder Tim Sweeney predicted that photorealistic games would require graphics cards with a computing power of roughly 5,000 teraflops. In a recent interview with GameSpot, Sweeney said today's hardware is already capable of rendering photo-realistic static scenes without humans with static lighting.
He estimated that photo-realistic dynamic environments with advanced shading models may require around forty teraflops, so basically a graphics card that's 4.5 times faster than a GeForce GTX 1080. This is without bringing human models into the equation, Sweeney said that will require a great deal more computing power. Here are the quotes from the interview:
Do you think that we'll ever approach photo-realistic graphics? If so, when, and how many Teraflops do you think we'll need?
You know, we're getting to the point now where we can render photo-realistic static scenes without humans with static lighting. Today's hardware can do that, so part of that problem is solved. Getting to the point of photo-realistic dynamic environments, especially with very advanced shading models like wet scenes, or reflective scenes, or anisotropic paint, though...maybe forty Teraflops is the level where we can achieve all of that.
Not with humans. Humans are the harder part, but that's just ...We know exactly how real world physics of lighting work, and so that's just a matter of brute force computing power. Give us enough computing power, and we can do that. We could do that today with algorithms that we know. Humans are a much harder problem, because rendering faces and skin is hard enough, but you quickly realize that the challenge with rendering humans is having realistic human motion to display. Having dynamic human responses in games are reactive to what you're doing, and aren't just pre-baked. As you're interacting with a real human, their eyes are constantly moving with you, the eye contact is super important. You're picking up the emotions on their faces, and they're dynamically responding to you. If you just used a perfect motion captured human, a flawless motion capture with future technology, it would still be uncanny and not feel like it's a real human interacting with you.
To do completely photo-realistic rendering of everything, you have to simulate realistic humans and actually simulate human intelligence, emotion, and thinking. It's not a matter of computing power. If you gave us an infinitely fast computer, we still don't have the algorithm. We have no real clue how the brain works at the higher levels. You might understand how one neuron interacts with other adjoining neurons, but the large scale structure of it is still a complete mystery. That could be unpredictably far away. Once we are able to simulate human intelligence, what's going to separate humans from people? You're talking singularity level stuff at that point, but I do think that we're many decades away from having that ability.