2D Lookat / Lookat2D

    public void Set(Vector3 pos, Vector3 dir)
    {
        transform.position = pos;
        transform.rotation = Quaternion.AngleAxis(Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg, Vector3.forward);
    }

    // dir = (target.pos - pos).normalize
    protected void LookAt2D(Vector3 dir)
    {
        transform.rotation = Quaternion.Euler(0, 0, Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg - 90);
    }