NVIDIA’s RTX technology lays the groundwork for photorealistic graphics on its Volta GPUs

NVIDIA just announced some cool new tech for GPUs that don’t exist yet. Today at GDC 2018, NVIDIA announced a graphics technology that video game developers have been clamouring after for a long time – real-time ray tracing, or the ability to render and illuminate a scene in real time.

The technology is essential to achieving photorealistic graphics in games, and it’s long been considered a holy grail of sorts in game rendering.

But what is it about ray tracing that lets it enable cinematic quality graphics and scenes? As its name suggests, ray tracing is a rendering technique that traces the path of light rays in a scene as they bounce off objects and illuminate areas around them.

In the real world, light also bounces off the objects in our vision. This light is absorbed, reflected, or refracted to varying degrees, and this determines how a certain scene appears to us.

Ray tracing is this process in reverse, where instead of tracing the path of light from its source to the eye, it follows the path of light from an imaginary viewpoint to the objects in an image. Ray tracing algorithms take into account things like the positions of light sources in a scene and the materials objects are made of.

When implemented well, ray tracing can enable super life-like images with realistic shadows, reflections, and lighting. Things like liquid, fire, and smoke can benefit as well and be given a more natural look.

However, the downside is that it’s incredibly demanding and requires a ton of computational power, which is why real-time ray tracing has been so elusive.

Till now that is. NVIDIA says its RTX technology will provide ray tracing acceleration for its Volta GPUs (and later ones too), thus allowing real-time ray tracing for games and other applications.

The company announced RTX in conjunction with Microsoft’s DirectX Raytracing (DXR) API announcement, and RTX is basically a backend implementation of DXR on NVIDIA’s end. NVIDIA is also working with Microsoft, so RTX is fully supported by DXR.

NVIDIA is leveraging a mix of software and hardware capabilities for RTX, so only Volta and other newer architectures will have the required hardware features to fully leverage DXR and RTX.

That said, NVIDIA also announced a GameWorks SDK with a ray-tracing denoiser module to allow game developers to take advantage of these new capabilities, so I should clarify that it’s these features that are the ones that are exclusive to Volta and later cards. According to NVIDIA, the SDK will enable ray-traced area shadows, ray-traced glossy reflections and ray-traced ambient occlusion.

In other words, DXR and RTX will support older graphics cards, but the new GameWorks features will be locked to Volta. This means that only Volta and newer GPUs will support new games using RTX.

Many game developers are already on board, and engine partners include Epic Games (Unreal Engine), EA (Frostbite) and Unity. On the developer side, EA, 4A Games, and Remedy have also signed up.

We may not even have to wait that long to see the fruits of these labors, with NVIDIA speculating that games using real-time tracing with DXR and RTX could arrive as soon as this year.



