Getting closer to simulating the real world: Applying ray tracing in games
Before diving into ray tracing ("RT" for short), let's first take a look at how illumination works in the real world. From the micro-perspective, the surface of an object illuminated by a ray of light is not perfect and smooth but has a lot of small bumps -- we call this a micro-surface. When light hits this uneven surface, the bumpiness causes light to be reflected in different directions, creating nuances in the real world. Given the huge number of light reflections and their complex pathways, it is extremely demanding from a computational perspective to simulate real-world lighting condit...
Source: gamesindustry.biz