1.解决的问题

通过OnDrawGizmos 使使用Physics.OverlapSphere 在编辑器或运行模式中可以方便的查看其范围

在Physics.OverlapSphere中加入扇形检测 ，效率更高

使用Debug.DrawLine(transform.position, transform.position+ right, Color.red); 绘制一些红线方便调试

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

public class test_jiance : MonoBehaviour {
    public float _max;

    //自视野自定义
    float minDistance = 2f;
    float minAngle = 40f;

    // Use this for initialization
    void Start () {
		
	}
	
	// Update is called once per frame
	void Update () {
      //注意：使用Physics.OverlapSphere 检测与被检测的物体需要加载rigibody 脚本
        var cols= new List<Collider>( Physics.OverlapSphere(transform.position, _max));
        //ebug.DrawLine(transform.position, pos, Color.red); ;

        cols.ForEach((s) =>
        {
            Debug.Log(s.name);
            SelfShiYe(s.gameObject.transform.position);
        }
            );
        

        


    }
    void SelfShiYe(Vector3 _tarPos)
    {

        float distance = Vector3.Distance(transform.position, _tarPos);

        //主角相对于目标的向量
        Vector3 srcLocalVect = _tarPos - transform.position;


        //获取正前方的点
        Vector3 forwardLocalPos = transform.forward * 1 + transform.position;

        //获取正方向向量
        Vector3 forwardLocalVect = forwardLocalPos - transform.position;
        forwardLocalVect.y = 0;

        //计算角度
        float angle = Vector3.Angle(srcLocalVect, forwardLocalVect);
        Vector3 left = Quaternion.Euler(0,-1* minAngle, 0) * transform.forward * 2;
        Vector3 right = Quaternion.Euler(0,  minAngle, 0) * transform.forward * 2;

        Debug.DrawLine(transform.position, transform.position+ left, Color.red); ;
        Debug.DrawLine(transform.position, transform.position+ right, Color.red); ;
        if (distance < minDistance && angle < minAngle / 2)
        {
            Debug.LogError("In EyeSight");
        }
    }
    //  绘制一个球
    void OnDrawGizmos()
    {
        Gizmos.color = Color.red;
        Gizmos.DrawWireSphere(transform.position, _max);
    }
}