removed no longer needed sorting by color

@@ -375,11 +375,6 @@ where T: Add<Output = T> + Sub<Output = T> + Neg<Output = T>
                            None
                        }};
 
-        let mut ps :Vec<(Polygon<T>, u32)> = self.faces.iter()
-                                           . filter_map(to_poly).collect();
-        // this sorts by the color value which is no longer neccessary as soon
-        // as the z-buffer is complete.
-        ps.sort_by(|a, b| a.1.cmp(&b.1));
-        ps
+        self.faces.iter().filter_map(to_poly).collect()
     }
 }