GGX shader for VRay PDF Print E-mail
Written by Sergey Shlyaev   
Sunday, 17 November 2013 03:54

GGX Shader for Vray

 

Ggx is a microfacet model which is very successful for modeling light reflection from surfaces.

In other words it's a shader like Blinn but 10x more awesome.


Ggx is based on distribution model from Trowbridge and Reitz.

This microfacet model [TR75, WMLT07] has a sharper peak and larger tails than Blinn or Phong.

For more details on ggx math please refer to original paper "Microfacet Models for Refraction through Rough Surfaces" by Bruce Walter et al.

Pricing and purchase details


Specular highlights comparison

ggx_vs_the_rest

 

Ggx and Blinn shaders applied to a sphere illuminated with hdr map.

See how ggx maintains highlights shape and has much more details for blurred reflections.

ggx_vs_blinn

 

Ggx vs. Blinn on a lower glossiness value. Images clickable.

blinn_04 ggx_04

It is physically correct shader with importance sampling.


Anisotropic support is in progress.


 

 

Render with ggx shader applied to complex model illuminated by hdr map.

statue_ggx

 

Closeup comparison of blinn vs. ggx. Notice how ggx has much more details.

blinn vs. ggx

Rendertimes:

01 min 37 sec for Blinn vs. 01 min 52 sec for Ggx with half-size render and preview quality.

10 min 24 sec for Blinn vs. 12 min 05 sec for Ggx with full size 1920x1080 render and 1 16 DMC samples.

 

Complex gold material done with ggx.


ggx_render

Boat image

 

 

Plugin interface.

It comes as BRDF plugin for VRay with plugin for Maya at a very reasonable price.

3dsmax version is also available.

ggx_3dsmax_preview

Ggx is a BRDF(bidirectional reflectance distribution function). This means it describes only how surface reflects the light

and does not describe e.g. refraction component.

When bump is needed, VrayBumpMaterial is used with ggx as base shader.

For other components like diffuse, refraction etc, it is used in conjunction with VrayBlend material.


Pricing and purchase details

3d test models are from:

The Stanford 3D Scanning Repository

 

Last Updated on Friday, 11 April 2014 01:44