BUG NOTE: the normals in the bunny and plane files ARE flipped!

The files for the above image are the same bunny as for the last program, and environment.urs. Note that antialiasing is optional. Gamma correction should make the colors look like the image above.

Important: there is a new color filed in the URS Material definition.

Material kd_r kd_g kd_b ke_r ke_g ke_b ks_r ks_g ks_b exp
Specifies the components of a Phong material model, Kd, Ks and the exponent.

       rgb background( const Vector3& v) const {
            if (v.y() > 0) { 
               double t = v.y();
               t *=t;
               return t*rgb(0.1,0.2,0.5) + (1-t)*rgb(1,1,1);
            }  
            else
               return rgb(0, 0, 0); 
       }