教程地址（观看视频需翻墙）：
https://learn.unity.com/project/c-survival-guide-rotations?language=en&courseId=5cf06bd1edbc2a58d7fc3209
1.初始化物体旋转角度为0
Instantiate(ObjectPrefab, transform.position, Quaternion.identity)；
2. 初始化物体带有旋转角度
Instantiate(ObjectPrefab, Vector3.zero, Quaternion.Euler(0, 35, 0));
3.物体始终转向目标物体
Vector3 directionToFace = _sphere.position - transform.position; //先算出与目标物体之间的位移差 Debug.DrawRay(transform.position, directionToFace, Color.green); //画出射线，可以很明显地看出与目标物体之间的关系 transform.rotation = Quaternion.LookRotation(directionToFace); //使用LookRotation让物体朝向目标体
4.物体缓慢转向目标物体
Vector3 directionToFace = _sphere.position - transform.position; Debug.DrawRay(transform.position, directionToFace, Color.green); Quaternion targetRotation = Quaternion.LookRotation(directionToFace); //先将旋转值保存出来
transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.deltaTime); //使用Slerp将旋转值以一定时间实现
