Unity3d LookAt参数说明 

//// 摘要: //     Rotates the transform so the forward vector points at target's current position.//// 参数: //   target://     Object to point towards.////   worldUp://     Vector specifying the upward direction.public void LookAt(Transform target, Vector3 worldUp);

其中 target为朝向的目标，worldUp为对象朝向目标后旋转自身，使得worldUp垂直z轴向上；

transform.LookAt(target,transform.right);	

transform.LookAt(target,-transform.right);	

transform.LookAt(target,transform.up);	

transform.LookAt(target,-transform.up);