NVIDIA today announced RTX, a GPU accelerated technology capable of producing photo-realistic imagery through realtime ray-tracing, all accelerated on the company’s latest generation of Volta GPUs.
Modern GPUs are capable of creating some pretty spectacular realtime imagery these days. Today’s gamers demand a level of visual fidelity unimaginable 10 years ago outside of dedicated 3D render farms, tasked with Hollywood-grade visual effects. And yet, for the most part, even the best looking games available today look as good as they do by utilising a series of rendering shortcuts that produce extremely convincing approximations of how we perceive the world around us, and no matter how good or precise those approximations get, there’s still something lacking.
Enter Ray-tracing, a method of calculating 3D scenes which mimics how we as humans perceive the world around us, or more specifically, how the light in our world is perceived by us. It’s a technique that has been around as long as 3D rendering itself, and works by painstakingly calculating beams of light from a source to its destination and how that beam bounces off, permeates through and is occluded by, objects in a scene. The upside of Ray Tracing is that, given enough time and computational power, resulting scenes can be indistinguishable from reality (or virtual reality).
The snag is of course, that calculating all of those light beams is extraordinarily compute intensive, such that any single scene could take many minutes or even hours to render an image which would please or fool the human eye. And until recently, even modern GPUs struggle with the level of number-crunching required to pull it off, but NVIDIA today announced RTX a “highly scalable ray-tracing technology running on NVIDIA Volta architecture GPUs,” that’s been “Architected to support ray tracing through a variety of interfaces.” One of those interfaces is Direct X’s Ray Tracing API DXR, which was also announced today by Microsoft at GDC 2018.
“Real-time ray tracing has been a dream of the graphics industry and game developers for decades, and NVIDIA RTX is bringing it to life,” said Tony Tamasi, senior vice president of content and technology at NVIDIA. “GPUs are only now becoming powerful enough to deliver real-time ray tracing for gaming applications, and will usher in a new era of next-generation visuals.”
For the moment, details are a little scant on how NVIDIA has managed to square the computational circle of real-time Ray Tracing, but for the moment at least a portion of the puzzle is tied up inside the company’s latest GPU architecture Volta, which the company has said includes a hardware “ray tracing engine”, although it seems much is offloaded in software to the hardware’s CUDA cores. The APIs and tools for developers to begin to leverage this new rendering engine will make their way into a new release of the company’s proprietary SDK Gameworks. NVIDIA is expected to unveil it’s Volta-based 20xx series GPUs at its own event, GTC 2018, next week.
As to when we’ll actually see applications or games utilising RTX and DXR, seems likely to be quite some time. Although (as you can see from the video embedded on this page) some developers have been able to integrate the new APIs already, with Remedy Entertainment (Max Payne, Alan Wake, Quantum Break) producing an impressive tech demo via the company’s Northlight game engine. For VR of course, advances in photo-realistic rendering have obvious implications, although quite when GPU power can scale to VR Ray-tracing boggles the mind.
