Based

I’m still learning things about physically based shading using my PBRViewer, and this time, I wanted to be able to experiment the variations of the Cook Torrance BRDF. The Cook Torrance BRDF looks like this: This equation is composed of three distinct terms: F: The fresnel, represents how the reflectivity change at grazing angles. G: The Geometry term, represents the probability that a microfacet will be visible from the light and view directions. D The normal distribution term, defines the distribution of the orientation of the microfacets. For more infomations you can read the very interesting " Physics and math of shading" by Naty Hoffman. For each term there is more than one possibility, and you can choose according to your need, and your budget the terms of your BRDF. Even if GGX is becoming the new standard, I wanted to experiment the other possibilities. ...

Physically based shading is more and more adopted and even if the core mechanism is pretty much always the same, the workflow may differ from an engine to another. For example let’s compare two common ones, often called Metallic and Specular. The metallic workflow uses a color input, the base color, and two scalar parameters, rouhghness and metallic. On a specular workflow there is two color inputs, an albedo and a specular, and a scalar, the roughness. ...

Physically based rendering is becoming the new standard for materials. It was already used a lot in AAA productions, and it’s now in Unreal Engine, Cry Engine and Unity. As a graphic programmer I’ve read a lot of papers and seen lots of presentation on that topic, but I never had the chance to try it. That’s why I made a small software, to be able to experiment both on a code and data point of view. ...