In a tech demo, which debuted at Nvidia's GPU Technology Conference in May, famed Japanese developer Square Enix recreated a cinema-quality, computer-generated character inside of a video game. Nyx Ulric, voiced by Aaron Paul in the CGI film Kingsglaive: Final Fantasy XV, had previously been confined to the silver screen, where the complexity of producing detailed computer graphics is offloaded to vast farms of computers one frame at a time (each taking hours to render), before 24 of them are pieced together to create a single second of film.

With top-of-line PC hardware from Nvidia (the server-grade Tesla V100, no less), Square Enix pulled character models and textures from the film and displayed them in real time using Luminous Studio Pro, the same engine that powers Final Fantasy XV on the Xbox One, PlayStation 4, and—with the upcoming release of Final Fantasy XV: Windows Edition in 2018—PC. Like any good tech demo, Kingsglaive is as impressive as it is impractical, featuring authentic modelling of hair, skin, leather, fur, and lighting that no PC or console on the market today can display (at least in 4K).

The Xbox One X, Microsoft's "most powerful console in the world," sports around six teraflops of processing power (FP32, for those technically inclined) to push graphics at 4K resolution—that's four times the number of pixels as a typical HD television. The Kingsglaive tech demo requires over 12 teraflops of processing power, more than is found in Nvidia's $1,000/£1,000 Titan Xp graphics card.

The man behind the audacious Kingsglaive demo is Final Fantasy XV Director Hajime Tabata, who—along with a talented team of artists and engineers at Square Enix—has created a string of graphical showpieces. Those include Agni's Philosophy and Witch Chapter 0 [cry], the latter of which used bleeding-edge software and hardware in the form of DirectX 12, an eight-core Intel processor, and four Nvidia Titan X graphics cards. Despite being only a few minutes long, both took over a year to produce.

"Even with the 12 teraflops of power behind [Kingsglaive], all we can get this character to do is stand in this ready position," laughs Tabata when I ask about the development of the demo. "To get him to start walking around, extra processing power is required. It wouldn't even work in this environment. Our expectation is that until you've got maybe two or three times the processing power of 12 teraflops, you won't be able to have characters of that quality and level of detail moving around freely in a game environment."

The Luminous engine that powers the Kingsglaive demo began life as "Ebony" in Final Fantasy Versus XIII (which became FFXV), before being merged with early versions of Luminous and technology from Visual Works, the company's CGI division. Now known as Luminous Studio Pro, Square Enix is pushing the engine towards an ambitious goal: to make video games that look as good as the pre-rendered CGI of Kingsglaive: Final Fantasy XV—and with each tech demo, Square Enix gets a little closer.

"The Witch Chapter demo was run full native 4K," explains Tabata, "but we realised that in order to do that if you have multiple cards and you have data transfer going on between those cards over SLI, there's a bottleneck there, and that causes problems. In order to overcome that for the home version we really do just want to go with one card, as that eliminates the data transfer calculations... What we've aimed for with Final Fantasy XV is that even with the richest environment possible, you still only need one reasonably high level card to drive it."