Allegorithmic presents a in-depth article on the interaction of light and matter and the basics of Physically-based rendering in this article.
Light is a complex phenomenon as it can exhibit properties of both a wave and a particle. As a result, different models have been created to describe the behavior of light. As texture artists, we are interested in the Light Ray Model as it describes the interaction of light and matter. It’s important for us to understand how light rays interact with surface matter because our job is to create textures that describe a surface. The textures and materials we author interact with light in our virtual worlds and the more we understand about how light behaves, the better our textures will look.
In this guide, we will discuss the theory behind the physics through which physically-based rendering models are based upon. We will start with a light ray and work up to defining the key factors for PBR.