Unity camera follows, the camera automatically zooms in and out to prevent characters from being blocked by obstructions

Not too much, just upload the code directly, and the script is hung on the camera

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

public class CameraFollow : MonoBehaviour
{
    //Vector3[] pos = new Vector3[8];
    //调试
    public float backDistance;//后面距离
    public float upDistance;//上面距离
    public float up;
    private Transform player;
    private Vector3 targetPos;
    RaycastHit hitInfo;
    public int cameraRotateSensitivity;//摄像机旋转灵敏度
    public int x=10;
    public float y = 0.8f;
    private float minDistance = 5f;
    private void Start()
    {
        cameraRotateSensitivity = PlayerPrefs.GetInt("cameraRotateSensitivity")+x;
        player = GameObject.FindGameObjectWithTag("Player").transform;
        transform.position = Vector3.Lerp(transform.position, player.position - player.forward * backDistance + player.up * upDistance, Time.deltaTime * cameraRotateSensitivity);
    }
    private void LateUpdate()
    {
        transform.position = Vector3.Lerp(transform.position, player.position - player.forward * backDistance + player.up * upDistance,Time.deltaTime*cameraRotateSensitivity); 
        targetPos = player.position+Vector3.up*up;
        transform.LookAt(targetPos);
        Physics.Raycast(targetPos,transform.position-targetPos,out hitInfo,Vector3.Magnitude(transform.position - targetPos)+y);
        Debug.Log(Vector3.Magnitude(transform.position - targetPos) + y);
        Debug.Log(Vector3.Magnitude(transform.position - targetPos));
        if(hitInfo.collider!=null)
        {
            if (hitInfo.collider.name != transform.gameObject.name)
            {
                transform.position = hitInfo.point +(targetPos- transform.position).normalized*y;
            }                        
        }                 
    }
}