比如在屏幕中有一条鱼，它可以向左或向右移动，固定时间旋转方向调换移动方向。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;public class fishMove: MonoBehaviour
{public int speed = 3;public Vector3 moveDirection=Vector3.left;private float timer;//改变方向的计时器public float changeDirectionInterval;//改变方向的时间间隔public Transform tss;void Update(){transform.Translate(speed * moveDirection * Time.deltaTime);timer += Time.deltaTime;//Debug.Log(timer);if (timer >= changeDirectionInterval){ChangeDirection();ChangeRotate();timer = 0;}}private void ChangeDirection(){if(moveDirection==Vector3.left){       moveDirection = Vector3.right;Debug.Log("3");}else if(moveDirection==Vector3.right){moveDirection = Vector3.left;}}private void ChangeRotate(){if (moveDirection.x==-1){tss.eulerAngles = new Vector3(0, 0, 0);}else if (moveDirection.x==1){tss.eulerAngles = new Vector3(0, 180, 0);}}
}