box_end.txt describes a cube peirced with three square holes.
            the cube has outer vertices x, y, z at 0.0 and 1.0
            the holes have inner vertices x, y, z at 0.333 and 0.666 
box_end.dat   data file defining vertices and surfaces
              all sections of surface are 4 point polygons
              there are 40 vertices and 48 polygons
box_endw.png  graphic of wire frame showing all edges
box_ends.png  graphic of cube with square holes
volume_dat_box_end.out  computation of volume and area
                        volume of material = 0.889558 
                        total surface area = 8.0

vertex numbering looking at 3D view
outter vertices            vertex 11 at x=1.0, y=1.0, z=1.0
                  12              11
                   *---------------*
                  /|              /|
             Y   / |             / |
             ^  /  |            /  |
             | /   |   Z       /   |
             |/    |  /       /    |  
            4*-- ------------*3    | 
             |     |/        |     |
             |    9*---------|-----*10
             |    /          |    /
             |   /           |   /
             |  /            |  /
             | /             | /
             |/              |/
             *---------------*   --> X
             1               2
vertex 1 at x=0.0, y=0.0, z=0.0
no material outside these boundaries


looking from outside the cube
front face vertices z=0     back face vertices z=1
  4               3         11              12
  *-- ------------*          *-- ------------*       
  |    8     7    |          |   15    16    |        
  |    *-----*    |          |    *-----*    |        
  |    |     |    |          |    |     |    |        
  |    |     |    |          |    |     |    |        
  |    *-----*    |          |    *-----*    |        
  |    5     6    |          |   14    13    |        
  |               |          |               |        
  *---------------*          *---------------*
  1               2         10               9        

left face vertices x=0      right face vertices x=1
 12               4          3              11
  *-- ------------*          *-- ------------*       
  |   19    18    |          |   22    23    |        
  |    *-----*    |          |    *-----*    |        
  |    |     |    |          |    |     |    |        
  |    |     |    |          |    |     |    |        
  |    *-----*    |          |    *-----*    |        
  |   20    17    |          |   21    24    |        
  |               |          |               |        
  *---------------*          *---------------*
  9               1          2              10        

bottom face vertices y=0    top face vertices y=1
  1               2         12              11
  *-- ------------*          *-- ------------*       
  |   25    26    |          |   32    31    |        
  |    *-----*    |          |    *-----*    |        
  |    |     |    |          |    |     |    |        
  |    |     |    |          |    |     |    |        
  |    *-----*    |          |    *-----*    |        
  |   28    27    |          |   29    30    |        
  |               |          |               |        
  *---------------*   --> X  *---------------*
  9              10          4               3        
      

looking at 3D view
inner vertices       vertex 39 at x=.666, y=.666, z=.666
center         40*-----------*39
                /|          /|
               / |         / |
              /  |        /  |
           36*-----------*35 |
             |   |       |   |
             | 37*-------|---*38
             |  /        |  /
             | /         | /
             |/          |/
           33*-----------*34
            
vertex 33 at x=.333, y=.333, z=.333
no material inside these boundaries
none of these are surfaces


   inner vertices front z=0         inner vertices back z=1
         36*-----------*35              16*-----------*15
          /|          /|                 /|          /|
         / |         / |                / |         / |
        /  |        /  |               /  |        /  |
      8*-----------*7  |            40*-----------*39 |
       |   |       |   |              |   |       |   |
       | 33*-------|---*34            | 13*-------|---*14
       |  /        |  /               |  /        |  /
       | /         | /                | /         | /
       |/          |/                 |/          |/
      5*-----------*6               37*-----------*38
            
vertex 5 at x=.333, y=.333, z=0.0  vertex 13 at x=.333, y=.333, z=1.0
vertex 7 at x=.666, y=.666, z=0.0  vertex 15 at x=.666, y=.666, z=1.0  
no material inside these boundaries
no surface  5, 6, 7, 8 and 33,34,35,36
no surface 37,38,39,40 and 13,14,15,16

   inner vertices left x=0         inner vertices right x=1
         19*-----------*40              39*-----------*23
          /|          /|                 /|          /|
         / |         / |                / |         / |
        /  |        /  |               /  |        /  |
     18*-----------*36 |            35*-----------*22 |
       |   |       |   |              |   |       |   |
       | 20*-------|---*37            | 38*-------|---*24
       |  /        |  /               |  /        |  /
       | /         | /                | /         | /
       |/          |/                 |/          |/
     17*-----------*33              34*-----------*21
            
vertex 17 at x=0.0, y=.333, z=.333  vertex 21 at x=1.0, y=.333, z=.333
vertex 19 at x=0.0, y=.666, z=.666  vertex 23 at x=1.0, y=.666, z=.666  
no material inside these boundaries
no surface 17,18,19,20 and 33,36,40,37
no surface 21,22,23,24 and 34,35,39,38

   inner vertices bottom y=0         inner vertices top y=1
         37*-----------*38              32*-----------*31
          /|          /|                 /|          /|
         / |         / |                / |         / |
        /  |        /  |               /  |        /  |
     33*-----------*34 |            29*-----------*30 |
       |   |       |   |              |   |       |   |
       | 28*-------|---*27            | 40*-------|---*39
       |  /        |  /               |  /        |  /
       | /         | /                | /         | /
       |/          |/                 |/          |/
     25*-----------*26              36*-----------*35
            
vertex 25 at x=.333, y=0.0, z=.333  vertex 29 at x=.333, y=1.0, z=.333
vertex 27 at x=.666, y=0.0, z=.666  vertex 31 at x=.666, y=1.0, z=.666  
no material inside these boundaries
no surface 25,26,27,28 and 33,34,38,37
no surface 29,30,31,32 and 33,34,38,37