/*
surface shader:
	brick_shiny_building

creator:
	Nick Meshes, DePaul University

description:
	Based on loosely screen.sl and shiny.sl
	Makes a surface that looks like an office building with reflective windows. Walls
	look plastic-like though.
	
parameters:
	Ka, Kd, Ks, roughness, specularcolor - work just like the plastic shader
	concretecolor = average color of concrete
	Kc = coefficient of change of color in concrete
 */

#include "noises.h"
#include "patterns.h"


surface
concrete (float Ka = .8, Kd = 0.75, Ks = 0.2, roughness = 0.2;
	   color concretecolor = color(0.682353, 0.643137, 0.643137);
	   color specularcolor = 0;
	   color Kc = .05
 )
{
	normal Nf = faceforward(normalize(N),I);
	vector IN = normalize(I);;
	float delta = .01 * snoise(P);
	concretecolor = (Kc * delta) + concretecolor ;

	Ci = concretecolor * (Ka*ambient() + Kd*diffuse(Nf)) + specularcolor * (Ks*specular(Nf,-IN,roughness));
	Oi = Os;
	Ci *= Oi;
}