how to make a gameobject face one direction independent of its parent's rotation

Unity Engine
1

I have a Plane that is inside a gameobject called NPC. I need the plane to always face south on the world axis. The npc parent is always changing its world axis and therefore changing the plane’s rotation. How can I set it up so that the plane is always facing south. I’ve tried

plane.transform.LookAt(Vector3.zero) and nothing, I’ve even tried this

plane.transform.eulerAngles = transform.TransformDirection(Vector3.zero);

2

Try (untested):

void Update() // Or LateUpdate()
{
    Vector3 direction = <whatever direction 'south' is in world space>
    Quaternion worldRotation = Quaternion.LookRotation(direction);
    Quaternion inverseParent = Quaternion.Inverse(transform.parent.rotation);
    transform.localRotation = inverseParent * worldRotation;
}
3

yes! that works just fine, thanks much