GGX shader for YafaRay

Project:YafaRay
Component:YafaRay Core
Category:feature request
Priority:normal
Assigned:David Bluecame
Status:needs work
Description

GGX is a microfacet shader for specular components that should solve some of the problems of the current microfacet model used for glossy specular, which produces too much of a 'plastic' look when used for reproducing metallic materials. Also another issue of the current model is that when maximum exponent is used for sharp glossy reflections, it does not converge to a true mirror reflection like in other software and some glossiness always remain. If implemented, this could solve also this feature request, as a glossy shader with maximun exponent is the only way to get sun disk on mirror like reflections from sun lamps and sun components in sunsky models in YafaRay.

http://www.neilblevins.com/cg_education/ggx/ggx.htm

http://www.shlyaev.com/rnd/37-cpp-category/54-ggx

I am going to do more request about texturing in the coming weeks so this is only one example of improvements we could do in that front. Greetings.

Comments

#1

Hi

About the idea about converging to a true mirror with full exponent with glossy material, this is what I mean taking as a comparison Marmoset Toolbag.

Comparison between YafaRay (left) and Marmoset (right) 100% strenght glossy specular models with full exponent. Marmoset toolbag converges to a true mirror reflection with full exponent, with both Blinn and Ggx microfacet shaders.

My work · Grey18 workflow · Sampling strategy · [url=http://www.yafaray.org/node/816]SPPM

#2

Assigned to:Anonymous» David Bluecame

#3

Version:» <none>
Component:Code» YafaRay Core
Status:active» needs work