Physically-Based Rendering

Physically Based Rendering (PBR) is a technique in computer graphics that aims to mimic the interaction of light with surfaces in the real world. It models how light behaves, from reflection to refraction, in a way that accurately represents reality. The PBR model factors in physical properties of materials, such as roughness or metallicity, making the rendering output more consistent and predictable under different lighting conditions. It uses complex shading algorithms and light calculations to generate a high level of realism. In order to achieve this, many PBR systems use a combination of two important components: the Bidirectional Reflectance Distribution Function (BRDF), which defines how light is reflected off an object, and the Bidirectional Surface Scattering Reflectance Distribution Function (BSSRDF), which handles how light scatters under the surface of an object.