Editing Vtk/SimpleCubeTutorial/CubeDetails (section)

===Defining the cube's six quadrilateral faces===
* The line of text that reads "POLYGONS 6 30" means that the subsequent 6 lines will, in sequence, identify the group of POINTS that should be connected to define the complete perimeter of each face of the cube.  For example, POINTS 0, 1, 2, &amp; 3 should be connected in order to create the cube face (POLYGON "0") that lies in the ''x-y'' plane &#8212; shown in the above image as the bottom of the cube.
* Each line of POLYGON-defining data must begin with an integer that tells the VTK reader how many ''additional'' integer numbers will appear on that line in order to define the desired polygon.  In the case being illustrated here, each of the 6 cube faces is being specified as a quadrilateral, so the first integer that appears in all six lines of POLYGON-defining data is "4."
* In total, the VTK reader must read in six lines of data with five integer numbers per line, for a total of <math>~6\times 5 = 30</math> integers, in order to completely understand how the cube is to be drawn.  This is why the integer "30" appears in the instructional heading, "POLYGONS 6 30."