public static GLKVector4 RotateVector4 (GLKQuaternion quaternion, GLKVector4 vector)
{
GLKQuaternion rotatedQuaternion = Make (vector.x, vector.y, vector.z, 0.0f);
rotatedQuaternion = Multiply (Multiply (quaternion, rotatedQuaternion), Invert (quaternion));
return GLKVector4.Make (rotatedQuaternion.x, rotatedQuaternion.y, rotatedQuaternion.z, vector.w);
}