Where come from about UNITY BRDF function

[dreamerflyer]

// Main Physically Based BRDF
// Derived from Disney work and based on Torrance-Sparrow micro-facet model
//
//   BRDF = kD / pi + kS * (D * V * F) / 4

In UnityStandardBRDF.cginc,i can not search this equation,and very different with Cook-Torrance-Sparrow model in http://maverick.inria.fr/~Nicolas.Holzschuch/cours/Slides/1b_Materiaux.pdf
Any body help?

[bgolus]

It’s going to be in one of the (many) Physically Based Shading papers from Disney Animation, starting from 2012 on. Pretty much every game and game engine today is using some version of the shading model they described in this paper: http://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf

There’s a lot more than that paper, but they’re strewn around the internet. But ultimately I believe Unity’s BRDF isn’t going to show up in any of them as it is born from their own internal research and modifications to those papers.

[dreamerflyer]

@bgolus

It’s going to be in one of the (many) Physically Based Shading papers from Disney Animation, starting from 2012 on. Pretty much every game and game engine today is using some version of the shading model they described in this paper: http://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf

There’s a lot more than that paper, but they’re strewn around the internet. But ultimately I believe Unity’s BRDF isn’t going to show up in any of them as it is born from their own internal research and modifications to those papers.

Thanks ~ According Cook-Torrance-Sparrow Model,the (DVF) maybe is(DGF),I confused with “V” term why not use
the common Name (G).
D: distribution function of facets orientation
F:Fresnel Factor
G:masking and shadowing

[neoshaman]

V is for Visibility term, which is Geometry term elsewhere. D i a l e c t

Reading those paper ain’t becoming easier, and also you need solid math background to get all the statistics term sipping from but never explained like Pdf (probability density function), which I do not and send me in long detective mode for relatively simple concept . It doesn’t halp that math writing is the entire opposite of a good code naming standard. And it has it’s numerous dialects where the same thing use different notation.

[dreamerflyer]

emm, i think that if using the same name will be good standard for using and promotion.

@neoshaman

V is for Visibility term, which is Geometry term elsewhere. D i a l e c t

Reading those paper ain’t becoming easier, and also you need solid math background to get all the statistics term sipping from but never explained like Pdf (probability density function), which I do not and send me in long detective mode for relatively simple concept . It doesn’t halp that math writing is the entire opposite of a good code naming standard. And it has it’s numerous dialects where the same thing use different notation.