code: function() {
              var abs = this.abs();
              if ((abs._x <= abs._y) && (abs._x <= abs._z)) {
                  return CSG.Vector3D.Create(1, 0, 0);
              } else if ((abs._y <= abs._x) && (abs._y <= abs._z)) {
                  return CSG.Vector3D.Create(0, 1, 0);
              } else {
                  return CSG.Vector3D.Create(0, 0, 1);
              }
          }
docs: find a vector that is somewhat perpendicular to this one