Unity 第三人称相机遮挡解决——设置相机挡位位置

设玩家上方为最差观察点，相机原始位置为最佳观察点，当相机看不到玩家时，相机向前推进一档，直到看到玩家为止，挡位数量越多，位置越精细。

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

public class CameraFllow : MonoBehaviour {

    /// <summary>
    /// 摄像机挡位数量，越多精度越高
    /// </summary>
    public int gears = 5;
    public float moveSpeed = 3f;
    public float smooth = 3f;

    private Transform fllowTarget;
    private Vector3 dir;

    private RaycastHit hit;

    private void Awake()
    {
        fllowTarget = GameObject.FindWithTag(StealthConst.PLAYER).GetComponent<Transform>();
    }

    // Use this for initialization
    void Start () {
        dir = fllowTarget.position - transform.position;
    }
    
    // Update is called once per frame
    void Update () {
        //计算起点坐标（最佳观察点）
        Vector3 start = fllowTarget.position - dir;
        // 计算终点(最差观察点)
        Vector3 end = fllowTarget.position + Vector3.up * (dir.magnitude-StealthConst.CAMERA_OFFSET);
        //声明并实例化观察点数组
        Vector3[] points = new Vector3[gears];
        //将起始点放置到数组
        points[0] = start;
        points[points.Length - 1] = end;
        //计算中间的点
        for (int i = 0; i < points.Length - 1; i++)
        {
            points[i] = Vector3.Lerp(start, end, (float)i / (gears - 1));
        }
        //声明合适的坐标(初值相当于备胎)
        Vector3 bestPos = start;
        for (int i = 0; i < points.Length; i++)
        {
            if (CheckPoint(points[i]))
            {
                bestPos = points[i];
                break;
            }
        }
        //平滑移动到指定位置
        transform.position = Vector3.Lerp(transform.position, bestPos, Time.deltaTime * moveSpeed);
        //平滑看向玩家
        Vector3 crDir = fllowTarget.position - bestPos;
        //转成四元数
        Quaternion quaternion = Quaternion.LookRotation(crDir);
        transform.rotation = Quaternion.Lerp(transform.rotation, quaternion, Time.deltaTime * 3f);
        transform.eulerAngles = new Vector3(transform.eulerAngles.x, 0, 0);
    }

    /// <summary>
    /// 能否看到玩家
    /// </summary>
    /// <param name="point"></param>
    /// <returns><c>true</c>可以看到 <c>false</c>不能s</returns>
    bool CheckPoint(Vector3 point)
    {
        Vector3 currentDir = fllowTarget.position + Vector3.up * StealthConst.PLAYER_OFFSET - point;
        if (Physics.Raycast(point, currentDir, out hit,Mathf.Infinity,1<<10))
        {
            if (hit.collider.CompareTag(StealthConst.PLAYER)) return true;
        }
        return false;
    }
}