//--------------------------------------------------------------------------------------
#include "shapes3.inc"
//--------------------------------------------------------------------------------------
#local D = 0.0001; // just a little bit, to avoid congruent surfaces in difference !!!
#local R_1 = 0.60;
#local R_2 = 0.30;
#local Center_Distance = 1.10;
#local Belt_Z = 0.40; // belt width in -z
#local Belt_D = 0.05; // belt thckness

difference{
 // Belt outer shape -------------------------------------------------------------------
 object{ Round_Conic_Prism(
           Center_Distance, // >0, vertical center distance of the upper and lower cycle
           R_1+Belt_D, // >0, upper radius up by <0,C_distance,0>
           R_2+Belt_D, // >0,  lower radius on zero !!!
           Belt_Z, // >0, length in z-
           0.00, // border radius, // max. = min(lower radius, upper radius)
           0 // Merge_On
         ) // --------------------------------------------------------------------------
       }  // end of object -------------------------------------------------------------

 // Belt inner shape -------------------------------------------------------------------
 object{ Round_Conic_Prism(
           Center_Distance, // >0, vertical center distance of the upper and lower cycle
           R_1, // >0, upper radius up by <0,C_distance,0>
           R_2, // >0,  lower radius on zero !!!
           Belt_Z+2*D, // >0, length in z-
           0.00, // border radius, // max. = min(lower radius, upper radius)
           0 // Merge_On
           ) // ------------------------------------------------------------------------
         translate<0,0.00,D>
       }  // end of object -------------------------------------------------------------
//--------------------------------------------------------------------------------------
 texture{ pigment{ color rgb<1,1,1> }
          finish { phong 1 }
        } // end of belt texture
} // end of difference
//--------------------------------------------------------------------------------------