public static Vector3D getCrossProduct(Vector3D a, Vector3D b)
	{
		double x = a.y * b.z - a.z * b.y;
		double y = a.z * b.x - a.x * b.z;
		double z = a.x * b.y - a.y * b.x;
		return new Vector3D(x, y, z);
	}