/*Wooksang's shader*/ 

#include "rmannotes.sl" 
surface
construction_end_line(
	       float Ks = 0.5, Kd=0.5, Ka = 0.1,roughness=0.1;
	       color first  = color(0.740,0.028,0.014);
	       color second = color(0.709,0.768,0.768);
	       color third  = color(0.496,0.473,0.475);
	       color forth  = color(0.089,0.090,0.260);
	       color specularcolor = 1;
	       varying point Pr = 0) 
{

/*basic setting*/

  color surface_color, layer_color=color(1,1,1); 
  float surface_opac, layer_opac; 
  float r,freq=5;  
  float dust=0;
  vector V;
  normal Nf;
  point PP,QQ;

  Nf=faceforward(normalize(N),I);
  V=-normalize(I);
  surface_color =0;
  surface_opac = 0;

    
/* layer #1 */

  surface_color = first;                  
  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*2),freq);
  layer_color = second;
  layer_opac = smoothstep(0.55,0.65,r)-smoothstep(0.75,0.85,r);
  surface_color = blend(surface_color, layer_color, layer_opac); 

/* Layer #2 */

  layer_color = third;  
  QQ = transform("shader", P);
  QQ += noise(QQ*2+2)*0.5; 
  r = distance (point (0,ycomp(QQ),zcomp(QQ)),point(1,1,1));
  r = repeat(r+snoise(r*2),freq);
  layer_opac = smoothstep(0.55,0.65,r)-smoothstep(0.75,0.85,r);
  surface_color = blend(surface_color, layer_color, layer_opac); 

/* layer #0 */

  layer_color = forth;                  
  PP = transform("shader", P);
  PP+= noise(PP*4)*0.5;
  r = distance (point (xcomp(PP),0,zcomp(PP)),point(1,1,1));
  r = repeat(r+snoise(r*4),40);
  layer_opac = smoothstep(0.55,0.65,r)-smoothstep(0.75,0.85,r);
  surface_color = blend(surface_color, layer_color, layer_opac); 
 

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