需要显示回弹功能的直接挂上就行

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
///

    // Update is called once per frame
    float rotateSpeed = 1;

//可以在外部inspector上勾选以方便多个旋转时方向不同步
    public bool isRotate_S = false;
    float timeNum = 5;
    float upNum = 0;
    void Update()
    {
        upNum += Time.deltaTime;
        if (upNum> timeNum)
        {
            upNum = 0;
            ChangeVct();
            isRotate_S = !isRotate_S;
        }
        var speed = (isRotate_S ? -rotateSpeed : rotateSpeed)*(0.5f+Mathf.Abs(0.5f- upNum/timeNum));
        var num = transform.localEulerAngles.z+ speed;
        transform.localRotation = Quaternion.Euler(0,0,num);
    }
    //不固定的时间回弹
    void ChangeVct()
    {

       //给个4-10秒的取值范围
        timeNum = 4 + Random.Range(0, 6);
        rotateSpeed = 0.4f + 0.5f * Random.Range(0, 1);
    }
}