Path Tracing, Nvidia’s Next Big Hit

Described as “the most accurate way of rendering”, Nvidia has showcased their new path tracing technology at GDC 2022, promises to overtake ray tracing in video games.

Path Tracing – Getting Started With Diffuse and Emissive « The blog at the bottom of the sea

What is path tracing?

Path tracing is an advanced type of light ray tracing that creates realistic lighting and shadows by bouncing light on a single pixel in random directions. These rays are traced over multiple bounces from the source of light to the destination rather than the light being traced in a linear method. While path tracing is a new feature to Nvidia, the concept of it is not a new idea as Unreal Engine has had support for path tracing for a few years.

There is footage on YouTube showcasing just how realistic footage can be with path tracing in UE 5. The following clip is a render and not real time path tracing that Nvidia aims to bring to their graphics cards, but it still shows the realism that can be achieved.

Since the introduction of the RTX series of Nvidia’s graphics cards, the company has focused on A.I technology to bring realism to games. The Turing series of cards introduced Tensor cores and RT cores which serve to aid A.I technologies in games. As amazing as this is, it does bring a downside with it, the amound of noise created from all the different rays being rendered simultaneously. This means that Tensor cores and RT cores are going to be far more important, considering how demanding ray tracing is even on current generation hardware.

So far Nvidia has only really shown the pwoer of path tracing in their Quake II RTX remake, which used textures from the original game release over 20 years ago, and implimented ray tracing and path tracing to enhance the graphics of the game, as seen below.

What is the difference between Ray Tracing & Path Tracing?

The two technologies are actually very closely related, as path tracing is a type of ray tracing. Ray tracing works by simulating light rays and then tracing them from their origin to the destination point. Path tracing on the other hand, works by taking a single light ray and bouncing it between the origin and destination in random directions, providing a more accurate and realistic rendering of how light would actually react in different scenarios.

There is speculation that the RTX 40 series will bring more support for path tracing, however nothing has been confirmed yet.

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