The future of graphics may very well be in real-time ray tracing, provided the hardware advances to the point where it can handle the added demands the technology requires. Slowly but surely we are getting there. In the meantime, NVIDIA is doing some interesting things in graphics, the latest of which is developing a pragmatic algorithm for real-time adaptive supersampling in games.
NVIDIA's algorithm extends temporal antialiasing (TAA) of rasterized images with adaptive ray tracing, and just as importantly, it conforms to the constraints of a commercial game engine and today's GPU ray tracing APIs, the company says. If that sounds like a bunch of techno-gibberish, the takeaway is it leverages ray tracing on today's tech to enable even prettier graphics.
"The algorithm removes blurring and ghosting artifacts associated with standard temporal antialiasing and achieves quality approaching 8X supersampling of geometry, shading, and materials while staying within the 33ms frame budget required of most games," NVIDIA explains.
A modern house scene in Unreal Engine 4 with deferred shading, ray traced shadows, and NVIDIA's adaptive temporal antialiasing technique rendered on a Titan V.
To demonstrate the image quality that is achievable with this method, NVIDIA implemented the adaptive temporal antialiasing (ATAA) algorithm in Unreal Engine 4 and ran it with a Titan V graphics card in Windows 10. On such a setup, NVIDIA says ATAA runs in 18.4ms at 8x supersampling, 9.3mx at 4x supersamping, and 4.6ms at 2x supersampling in one of its demo images, at 1920x1080.
"Primary surface aliasing is a cornerstone problem in computer graphics. The best known solution for offline rendering is adaptive supersampling. This was previously impractical for rasterization renderers in the context of complex materials and scenes because there was no way to efficiently rasterize sparse pixels. Even the most efficient GPU ray tracers required duplicated shaders and scene data," NVIDIA explains in a white paper.
NVIDIA's fancy algorithm presents a practical solution to the problem, though do not expect to see it rolled out to the current generation of GeForce cards. This method is dominated by the ray trace and requires a fair amount of horsepower. However, NVIDIA says it is not that concerned with this, given that mainstream gaming GPUs have not yet appeared that support the related DirectX Ray Tracing (DXR) API.
"The real-time ray tracing ecosystem of drivers, GPUs, and algorithms must emerge together over the next few years," NVIDIA concludes.