The primary goal of physically-based rendering (PBR) is to create a simulation that accurately reproduces the imaging process of electro-magnetic spectrum radiation incident to an observer. This simulation should be indistinguishable from reality for a similar observer.Great care was taken to not use the words human and colour (or even light) in the previous description: Indeed, often and especially in the Visual Effects industry, the observer is a motion picture or stills camera. A typical came...