anchor.diff:    return min(max(d.x,max(d.y,d.z)),0.0) + length(max(d,0.0));
   }
   
  -//float udBox( vec3 p, vec3 b )
  -//{
  -//  return length(max(abs(p)-b,0.0));
  -//}
  -
   float sdCylinder( vec3 p, float r )
   {
     return length(p.xz)-r;
  
positive.code: 	return res;
  }
  
  float shadow(in vec3 ro, in vec3 rd, float mint, float maxt)
  {
      float t = 0.1;
      for(float _ = 0.0; _ == 0.0; _ += 0.0)
  
negative.code:     }
      return 1.0;
  }
  #else
  #define shadowFunction(ro, rd, mint, maxt) 1.0
  #endif
  
  void addLight(inout vec3 diffRes, inout float specRes, vec3 normal, vec3 eye, vec3 lightPos, vec3 lightCol, float shadow)
  {
  