// Persistence of Vision Ray Tracer Scene Description File
// File: unwrap.pov
// Vers: 3.5
// Desc: Cylindrically unrolls an object.
// Date:
// Auth: Barrett L. Bowen aka "Batronyx" ^"^
// Suggested commandline settings:
// +w800 +h533
// +w300 +h200 

/************************************************************
     This file takes an object and cylindrically unrolls it 
     around the y-axis. This can be useful for objects that
     do not support UV-mapping by serving as a background
     layer in paint programs to guide texture creation, or 
     as a morph target in image morphing applications ( i.e.
     Hijaak Morph) 
     
     The camera ensures the clip object is
     always 1 pixel wide. It is centered across pixel boundaries
     though so (assuming a single base object) you will always
     wind up with image_width+1 objects. 
     
     The base object should be generally suitable to either 
     cylindrical or spherical mapping. There are no lights
     and depth style gradient textures are recommended.
     Also, the initial object should face the +z direction
     as this will be the center of the unwrapped image.
*************************************************************/


camera {
  orthographic
  location <0,0,-1000> 
  right x*image_width 
  up y*image_heigh
}

#include "transforms.inc"
#declare Cutter = // Clipping object 
     intersection{
          plane { x .5}
          plane {-x .5}
          plane {z 0.05}
     }
     
//spherical, onion, cylindrical, or even radial might all be useful here
#declare WrapTex= texture{
     pigment{wood  ramp_wave 
          color_map { 
               [0 color rgb 0]
               [1 color rgb 1]
          }
          //rotate x*-90
     }
     finish { ambient 1}
}


#declare Wrapobject = 
     /* Some object here */ 
     Center_Trans(Wrapobject, x+y+z)}

//Get some measurements to use later.
#declare skMin = min_extent(Wrapobject);
#declare skMax = max_extent(Wrapobject);
#declare FitScaleY = transform{ scale ((image_height/2)/(skMax.y))}

// Scale so top to bottom fits the screen.     
#declare Wrapobject = object{Wrapobject 
     transform{FitScaleY}
}    

//Get new min & max extents for the properly scaled version.
#declare skMin = min_extent(Wrapobject);
#declare skMax = max_extent(Wrapobject);

//Now slice and dice :)
#declare Count = 0;
#declare Trans = -image_width/2;
#while (Count <= image_width)
     object{ Wrapobject 
          //rotate y*180             // orient the front to +z 
          rotate y* ((Count/image_width)* 360) 
          Align_Trans(Wrapobject, -z, <0,0,skMin.z>)
          clipped_by {Cutter}      // take a slice here
          translate x*Trans          // and move it to the correct spot
     }
     #declare Count = Count +1;
     #declare Trans = Trans + 1;
#end