Ray Tracing Isn't a Gimmick, It's a Way Bigger Deal Than You Think

howtogeek.com:

Are you unimpressed with how ray tracing is being implemented on current-generation consoles? Are you questioning what all of the fuss is about? Let’s take a step back and reassess what ray tracing means for games.

Ray Tracing Isn't Just a Toggle

All too often the term “ray tracing” is used as a be-all-end-all term that is somehow translated into “superior image quality,” but there’s a lot more to it than that. Ray tracing is a real-time rendering technique, but one that encompasses a multitude of elements that affect final image quality.

The most obvious examples that spring to mind are reflections and shadows. Ray-traced reflections offer a true like-for-like mirror of whatever is in the scene, albeit with varying degrees of fidelity owing to available processing power. Ray-traced shadows work in the same way, generating accurate real-time shadows based on the position of light sources within the scene.

There are also techniques with slightly more complex-sounding names, that make a huge difference. Ray-traced ambient occlusion calculates how ambient lightning affects different objects in a scene, applying shadows to geometry in a natural way. Think about the way you might find shadows in the corner of a room, or on the underside of a rock.

Ray-traced global illumination works in tandem with this technique to generate realistic and real-time whole-scene lightning. This encompasses the way the sun’s rays scatter within a scene. Bounced light is just as important here, softening darker parts of the scene and even reflecting the hue of nearby objects (like green grass reflecting on the underside of a rock).

Ray tracing is an umbrella term for a whole variety of techniques that effectively simulate the way light fills a scene, eliminating the need to “fake” lighting and removing the telltale signs of traditional “rasterized” lighting. These techniques can be turned on and off as necessary. If you’re a PC gamer, you’re often left to your own devices, while