Even 'flat' or 'matte' surfaces in the real world such as concrete will reflect a small degree of light, and many metals and liquids will reflect a great deal of it. One of these is that – unlike many previous models that sought to differentiate surfaces between non-reflective and reflective – PBR recognizes that, in the real world, as John Hable puts it, 'everything is shiny'. PBR is, as Joe Wilson puts it, 'more of a concept than a strict set of rules' – but the concept contains several distinctive points of note. The phrase 'Physically Based Rendering' was more widely popularized by Matt Pharr, Greg Humphreys, and Pat Hanrahan in their book of the same name from 2014, a seminal work in modern computer graphics that won its authors a Technical Achievement Academy Award for special effects.

Much of this work was done at the Cornell University Program of Computer Graphics a 1997 paper from that lab describes the work done at Cornell in this area to that point. Starting in the 1980s, a number of rendering researchers worked on establishing a solid theoretical basis for rendering, including physical correctness. PBR principles may be implemented in real-time applications using Shaders or offline applications using Ray tracing (graphics) or Path tracing. Photogrammetry may be used to help discover and encode accurate optical properties of materials.

Feasible and quick approximations of the bidirectional reflectance distribution function and rendering equation are of mathematical importance in this field. Many PBR pipelines aim to achieve photorealism.

Physically based rendering ( PBR) is a computer graphics approach that seeks to render images in a way that models the flow of light in the real world. Tessellation is used to generate an object mesh from a heightmap and normal map, creating greater detail. Even though this is a rough, opaque surface, more than just diffuse light is reflected from the brighter side of the material, creating small highlights, because 'everything is shiny' in the physically-based rendering model of the real world.

Blender cycles lighting