Assets/FollowDestination.cs(6,13): error CS0246: The type or namespace name `NavMeshAgent' could not be found. Are you missing `UnityEngine.AI' using directive?的解决方案

问题的出现与描述

在Unity中创建一个NPC，使它一直跟踪一个目标Destination，C#脚本代码如下，错误信息描述如下

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

public class FollowDestination : MonoBehaviour {
    private NavMeshAgent ThisAgent = null;
    public Transform Destination = null;

    void Awake()
    {
        ThisAgent = GetComponent<NavMeshAgent>();
    }
    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {
        ThisAgent.SetDestination(Destination.position);
    }
}

解决方案

根据提示信息我知道原因是 “缺失的是引用UnityEngine.AI命名空间的指令 ”，所以我们要在FollowDestination.cs 中加上 using UnityEngine.AI。