/*Wooksang's shader for construction
*layer_1 made blended color with tuberance and spline
*layer_2 made black part with (1-layer_opac) 
*layer_line for line in surface*/ 

#include "rmannotes.sl" 

surface
sculpture_animation(
	 float Ks=0.1,Kd=0.7,Ka=0.1,freqR = 6,Km=0.1,roughness=.1;
	 varying point Pr = 0;
	 float ani =0; 
	 color specularcolor=1,
	 White  = color(1,1,1),
	 Yellow = color(0.943,0.795,0.302),
	 Blue   = color(0.394,0.531,0.943),
	 Red    = color(0.943,0.162,0.109),
	 Black  = color(0,0,0),
	 Darkblue  = color(0.091,0.159,0.276),
	 Darkred  = color(0.138,0,0);)
{
  color surface_color,layer_color=color(1,1,1),grey=0;
  float layer_opac,r,freq=5;
  point PP,QQ,newP;
  float size=4, i,opac=0,opac1=0,turb=0;
  normal Nf;
  vector V;
  
/*  Nf = faceforward( normalize(N), I );
  V = -normalize(I);*/
  
  surface_color=color(1,1,1);
  layer_opac=0;
  
  /*layer #1*/
  QQ=transform("shader",P);
  surface_color=White;
  for(i=0;i<freqR;i+=1){
    layer_opac+=abs(0.7-noise(QQ*size+pow(ani*0.02,2)))/size;
    size*=2;
    opac=clamp(layer_opac*4,0,1);
    surface_color=spline(opac,White,White,Red,Black,White,Darkblue,Yellow,White,White);
    surface_color=blend(surface_color,layer_color,layer_opac);
  }
  
  /* layer #2*/  
  layer_color=color(0.203,0.161,0.134);
  for(i=0;i<freqR;i+=1){
    layer_opac+=abs(0.75-noise(QQ*size))/size;
    size*=2; 
    opac1=layer_opac;
    surface_color=blend(surface_color,layer_color,layer_opac);
    }
  grey = surface_color;
  /*lay_line*/
  PP = transform("shader", P);
  PP += noise(PP*4+3)*0.5;
  r = distance (point (0,ycomp(PP),zcomp(PP)),point(1,1,1));
  r = repeat(r+snoise(r*4),freq);
  layer_color = color(0,0,0);
  layer_opac=0;
  layer_opac = (step(0.6,r)-step(0.8,r))*0.5;
  surface_color = blend(surface_color, layer_color, layer_opac);

  /*change color to gray*/
  turb=0.299*comp(grey,0)
    +0.587*comp(grey,1)
    +0.114*comp(grey,2);


  /* bump */

  newP = calculatenormal(P+turb*Km*normalize(N));
  Nf   = faceforward(normalize(newP),I);
  V    = -normalize(I);

 Ci = Os * ( surface_color * (Ka*ambient()+Kd*diffuse(Nf))+
	      specularcolor * Ks * specular(Nf,V,roughness));
}