notes on esherish.inc

1.  Installation:  copy "escherish.inc" to your povray include directory -- that's it.
2.  Use:
	a.  In your scene file, include "escherish.inc".
	
	b.  Put the following line in your scene file:
		  #declare sides=[x];
		-->replace [x] with an integer greater than or equal to 3.  this number gives
		   the number of "sides" of the figure.
		   
	c.  Put the following line after declaring the number of "sides" of your figure:
		  Init_Arrays(sides)
		  
	d.  If you do not want to define the textures of each of the "sides" of your figure, then
	    put the following line in your scene file:
		  #declare seedish = [xxxx];
		-->replace [xxxx] with any integer; this causes the main macro to randomly assign
			textures to each of the "sides" of the figure.
			
	e.  If you do wish to define the textures for the "sides", you must declare them all.
	    Declare them like the following:
	        #declare textures[0] = texture{TEXTURE CODE};
                #declare textures[1] = texture{MORE TEXTURE CODE};
                        ....and so on until....
                #declare textures[sides-1] = texture{LAST SIDE TEXTURE CODE};
                
	f.  Put the following lines in your scene file:
	        #declare wideness=[y1];
	        #declare radiuss=[y2];
	        #declare thicknesss=[y3];		
                --->[y1] is a real positive number, it controls the width of the "sides"
                --->[y2] is a real positive number, it controls the length of the "sides"
                --->[y3] is a real positive number, it controls the thickness of the lines outlining the "sides"
                
        g.  If you want to change the default texture of the outline lines put the following in your scene file.
                #declare outline_tex=texture{SOME KIND OF TEXTURE CODE}
                
        h.  The outline lines are, by default, made up of cylinders and spheres.
                If you prefer, you can change them to boxes and cylinders, giving the outline lines a flat top,
                instead of the rounded top of cylinders and spheres.
                To use the boxes and cylinders for the outline lines put the following lines in your scene file:
                #declare flat_border=1;
                #declare ht = [z];
                --->[z] is a real positive number, it controls the height of the outline lines.
                
        i.  Now put the following line in your scene file:
                Create_Figure(wideness,radiuss,sides,thicknesss)
            This line defines an object with the name of "figure".  This object is your impossible figure.
            For all practical purposes, unless you have used some really off the wall numbers, this is a mostly flat
            figure that lies perpendicular to the Z axis, in the XY plane.  To have this figure render, put a line
            like the following in your scene file:
                object{figure}
            You can put in rotation, translation and other usual object things in the {}'s along with the figure,
            just like any other object{} statement.  Then aim the camera at your figure, throw in a light source,
            and you have your scene.  There are some example scenes in the zip file containing this readme.
            Use them, distort them, whatever.  Keep in mind the code does not have error checking in it...if you enter
            strange enough numbers, you may get results that do not look like an Escher impossible figure at all.
            Enjoy....
                            
