Unity 摄像机跟随，摄像机自动拉近和远离，防止人物被遮挡物遮挡

不多逼逼，直接上代码，脚本挂在摄像机上

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;
            }                        
        }                 
    }
}