"Jessie K. Blair" <lor### [at] aolcom> wrote in message
news:3e14d010@news.povray.org...
> I do not know the coordinates, or how to calculate them.  Can you tell me
> how to calculate them as well?

/*
Check this one:
a sphere grid consists of 8 identical parts.
Just one may be enough, however,
but it may be also convenient to have all eight.
*/
//----------------8<----------------
#local SphereObjectCentre=<0,0,0>;
#local SphereObjectR=1;
#local N=8;
#local PointR=1/N;

#local SphereObjectColor=<.1,1.3,1.6>;
#local PointColor=<0.8,1.5,0.2>;

#local nPonts=N*(N+1)/2;
#local Point=array[8][nPonts];

#local Alpha=pi/2;
#local dAlpha=Alpha/(N-1);

#local CurrentPoint=<0,SphereObjectR,0>;

#local Point[0][0]=CurrentPoint;
#local Alpha=Alpha-dAlpha;
#local k=0;
#local i=1;
#while (i<N)
  #local Beta=0;
  #local dBeta=pi/2/i;
  #local j=0;
  #while (j<i+1)

    #local k=k+1;
    #local CurrentPoint=
      SphereObjectR*<cos(Alpha)*sin(Beta),
                sin(Alpha),
                cos(Alpha)*cos(Beta)>;

    #local Point[0][k]=CurrentPoint;

    #local Beta=Beta+dBeta;

    #local j=j+1;
  #end

  #local Alpha=Alpha-dAlpha;
  #local i=i+1;
#end

// Here we have a 1/8 part of sphere surface

#local k=0;
#while (k<nPonts)     // Filling next parts
  #local Point[1][k]=<Point[0][k].z,Point[0][k].y,-Point[0][k].x>;
  #local Point[2][k]=<-Point[0][k].x,Point[0][k].y,-Point[0][k].z>;
  #local Point[3][k]=<-Point[0][k].z,Point[0][k].y,Point[0][k].x>;
  #local Point[4][k]=<Point[0][k].x,-Point[0][k].y,Point[0][k].z>;
  #local Point[5][k]=<Point[1][k].x,-Point[1][k].y,Point[1][k].z>;
  #local Point[6][k]=<Point[2][k].x,-Point[2][k].y,Point[2][k].z>;
  #local Point[7][k]=<Point[3][k].x,-Point[3][k].y,Point[3][k].z>;
  #local k=k+1;
#end

#local SphereObject=sphere{
  SphereObjectCentre,
  SphereObjectR
  pigment{color rgb PointColor}
}

#local PontsObject=union{

// North Pole
  sphere{Point[0][0],PointR
    pigment{color rgb SphereObjectColor}
  }
// South Pole
  sphere{Point[4][0],PointR
    pigment{color rgb SphereObjectColor}
  }

  #local k=0;
  #while (k<8)
    #local m=1;
    #local i=1;
    #while (i<N)
      #local j=0;
      #while (j< ((k<4)?(i+1):i))
         //Prevent of forming the Equator twice

        sphere{Point[k][m+j],PointR
          pigment{color rgb SphereObjectColor}
        }

        #local j=j+1;
      #end
      #local m=m+j;
      #local i=i+1;
    #end
    #local k=k+1;
  #end
}

camera {
  location <-2,2,-2>*1.2 look_at SphereObjectCentre
  right x*image_width/image_height
  up y
}

background { color rgb <1,1,1>}

light_source {
  0*x
  color rgb <1,1,1>
  translate <-20, 40, -20>
}

#object{SphereObject}
#object{PontsObject}

//----------------8<----------------

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