Visualization of custom BRDFs defined through a GLSL pre-defined syntaxis, with the following form:
# variables go here...
# only floats and boolean supported right now.
::begin parameters
float name [min val] [max val] [default val]
bool name default val
::end parameters
::begin reflectanceShader
vec3 BRDF(vec3 L, vec3 N, vec3 V, vec3 X, vec3 Y)
{
...
return N * length;
}
::end reflectanceShader
::begin renderingShader
vec3 BRDF( vec3 kad, vec3 ks, float shadowDiffuse, float shadowSpecular, vec3 L, vec3 N, vec3 V, vec3 X, vec3 Y )
{
...
return shadowDiffuse * color * brdfFactor;
}
::end renderingShader
By default, this work integrates six different shaders for typical BRDFs, including Phong, Lambertian, Cook-Torrance, Minnaert, Ward (anisotropic) and Oren-Nayar. The integration and reload of new shaders included by users are still pending. Currently, the provided shaders can be redone to build a custom BRDF function.
They can be either visualized as an implicit function mapped into a unit sphere, or by rendering a dragon mesh coloured with the implemented BRDF. Both kinds of visualization are following depicted:
