// Persistence of Vision Ray Tracer Scene Description File
// File: ?.pov
// Vers: 3.6
// Desc: Basic Scene Example
// Date: mm/dd/yy
// Auth: ?
//
         

#version 3.6;

#include "colors.inc"

global_settings {
  assumed_gamma 2.1    
  // used in global_settings, sets an overall brightness/ambient light level in the scene
  ambient_light color rgb <1,1,1>/10
}

// ----------------------------------------

camera {
  location  <+0.3, 0.5, -4.0>     // -0.2  0.0  +0.2    //  -0.3 -0.1 +0.1 +0.3
  direction 1.5*z
  right     x*image_width/image_height
  look_at   <0.0, 0.0,  0.0>
}

sky_sphere {
  pigment {
    gradient y
    color_map {
      [0.0 rgb <0.6,0.7,1.0>]
      [0.7 rgb <0.0,0.1,0.8>]
    }
  }
}

light_source {
  <-50, 40, -60>            // light's position (translated below)
  color rgb <0, 0, 0>  // light's color
}     

light_source {
  <50, 40, -60>            // light's position (translated below)
  color rgb <0, 0, 0>  // light's color
}

light_source {
  <0, 190, -60>            // light's position (translated below)
  color rgb <0, 0, 0>  // light's color
  
}

// ----------------------------------------

plane {
  y, -1.3
  pigment { color rgb <0,0,0> }
}

#declare ba=15;
#declare bb=15;  //6 , 9 ,    , 15
#declare b1=max(ba,bb);

#declare s=sqrt(3)/2;        

  
//tube armchair
#declare bb=bb+6;  //6 , 9 ,    , 15
#declare r=(bb-6)/pi;
#macro ab2y(b,a) sin(a/r)*r  
#end
#macro ab2x(b,a)  b 
#end
#macro ab2z(b,a)  -r
#end
 

    /*
//rim armchair
#declare r=(bb-6)/pi*3;
#macro ab2y(b,a)   
#end
#macro ab2x(b,a)  b 
#end
#macro ab2z(b,a)    -r
#end
  */

  /*
//ribbon
#macro ab2x(a,b) a 
#end
#macro ab2y(a,b)  b 
#end
#macro ab2z(a,b)  0 
#end        
 */

    /*
//rim zizag
#declare r=(ba*s)/pi*3;
#macro ab2x(a,b) sin(a/r)*r 
#end
#macro ab2y(a,b)  b 
#end
#macro ab2z(a,b)  -r
#end        
  */

    /*   
//tube zizag
#declare ba=ba+2;
#declare r=(ba*s)/pi;
#macro ab2x(a,b) sin(a/r)*r 
#end
#macro ab2y(a,b)  b 
#end
#macro ab2z(a,b)    -r
#end

  */   

union{   

#declare m = -b1;
#while (m < b1)
#declare n = -b1;
#while (n < b1)
//#declare BallCount = 0;
// #while (BallCount < 2*pi)
                #declare a0=(n*2+m)*s   ;
                #declare b0=m*1.5        ;
                
#if  ((a0<ba) & (a0>-ba) & (b0<bb) & (b0>-bb) )
        union{ 
                          

                #if (b0>-bb+2)
                sphere {< ab2x(a0,b0), ab2y(a0,b0),ab2z(a0,b0)>, 0.5         }
                #end
                #if ((b0<bb-2) & (b0>-bb+2))
                cylinder {< ab2x(a0,b0), ab2y(a0,b0),ab2z(a0,b0)>,< ab2x(a0,b0+1), ab2y(a0,b0+1),ab2z(a0,b0+1)>,  0.35 }
                #end
                #if (b0<bb-2)
                sphere {< ab2x(a0,b0+1), ab2y(a0,b0+1),ab2z(a0,b0+1)>, 0.5         }
                
                #if (a0+s<ba)
                cylinder {< ab2x(a0,b0+1), ab2y(a0,b0+1),ab2z(a0,b0+1)>,< ab2x(a0+s,b0+1.5), ab2y(a0+s,b0+1.5),ab2z(a0+s,b0+1.5)>,  0.35 }
                #end
                #if (a0-s>-ba)
                cylinder {< ab2x(a0,b0+1), ab2y(a0,b0+1),ab2z(a0,b0+1)>,< ab2x(a0-s,b0+1.5), ab2y(a0-s,b0+1.5),ab2z(a0-s,b0+1.5)>,  0.35 }
                #end
                #end
        }
        #end
               //  rotate <0,BallCount*60,0>}
               //  rotate <0,BallCount*60-30,0>}
// #declare BallCount = BallCount+pi/3;   // increment our counter
//  #end
#declare n = n+1;   // increment our counter
#end
#declare m = m+1;   // increment our counter
#end

         texture {
            pigment {
                color rgb <0,0,0>*0.7
            }
            finish{
              specular 0.6
            }
         }
     scale 0.08 //2
   //  translate 0.4*z
     rotate <90,45,0>
     rotate <-20,0,0>
   //  translate z        
}

I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.