def cross(self, vec):
        """Return the crossproduct between self and vec."""

        return Vec3(self.y * vec.z - self.z * vec.y,
                    self.z * vec.x - self.x * vec.z,
                    self.x * vec.y - self.y * vec.x)
def cross ( self , vec ) : return Vec3 ( self . y * vec . z - self . z * vec . y , self . z * vec . x - self . x * vec . z , self . x * vec . y - self . y * vec . x )
Return the crossproduct between self and vec.