Roughly a decade ago, Intel was hyping the benefits of real-time ray tracing, and pronounced that it would replace traditional rasterization in 3D games. Intel hoped to blaze a trail in this new direction for 3D graphics with its Larrabee GPU architecture, but the company eventually gave up on those efforts. NVIDIA, however, was more than willing to take the torch with the aim to bring more realism to 3D content via ray tracing technologies.
But before we delve into what NVIDIA has in store, let's talk more about what ray tracing actually is. Ray tracing is a method by which images are created by tracing rays or paths of light as they bounce in and around an object (or objects) in a scene. Under optimum conditions, ray tracing delivers photorealistic imagery with shadows that are correctly cast; water effects that show proper reflections and coloring; and scenes that are cast with realistic lighting effects. Imagine more convincing smoke and explosion effects, etc. The complex optical calculations that are used for ray tracing means that people and objects in games will appear more lifelike, since objects will be more naturally lit by the environment.
Up until this point, however, the actual performance hit associated with real-time ray tracing has been too great to overcome with existing GPU hardware. The computational horsepower required to produce life-like imagery and effects at acceptable frame-rates has eluded us -- until now, says NVIDIA.
With NVIDIA RTX, which is highly scalable, NVIDIA is using its Volta GPU architecture to bring the technology that has long been used in films to pre-render life-like environments to gaming. Although NVIDIA never told us when Volta was first announced, the GPU architecture actually has specific hardware features onboard (in addition to the Tensor cores) to help accelerate ray tracing. The company isn't really offering up any more information on this hardware at the moment. And while NVIDIA won't delve into actual performance benchmarks, it did note that Volta is “multiple integers faster” than previous generation architectures when it comes to ray tracing.
"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," says Tony Tamasi, SVP of content and technology for 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."
The graphics powerhouse has even garnered industry support for NVIDIA RTX, as it has worked hand-in-hand with Microsoft to incorporate it into the new DirectX Raytracing (DXR) API. Any GPU capable of DirectX 12-class compute should be able to run DXR, but performance and efficiency will vary widely depending on the architecture.
"DirectX Raytracing is the latest example of Microsoft's commitment toward enabling developers to create incredible experiences using cutting-edge graphics innovations," adds Max Mullen, Microsoft development manager for Windows Graphics and AI.
The NVIDIA GameWorks SDK has also been updated with a ray-tracing denoiser module for developers that want to take advantage of NVIDIA RTX and the DXR API. The new version of the GameWorks SDK will enable support for ray-traced glossy reflections, ambient occlusion and area shadows. This will be supported on Volta GPU hardware and future GPU products from NVIDIA.
And to show what's possible with NVIDIA RTX, developers including Epic, 4A Games and Remedy Entertainment will be showcasing their own technology demonstrations this week at the Game Developers Conference. NVIDIA expects the ramp to be slow and measured at first, like it was initially for pixel shaders, but eventually most game developers will adopt a long-term play for real-time ray tracing in the future.