def to_vec3(self):
        """Convert this vector4 instance into a vector3 instance."""
        vec3 = Vector3()
        vec3.x = self.x
        vec3.y = self.y
        vec3.z = self.z

        if self.w != 0:
            vec3 /= self.w

        return vec3
Convert this vector4 instance into a vector3 instance.