我在Unity3D中尝试使用A*路径查找算法，当目标保持静止时它能正常工作。然而，如果目标移动，单位仍然会遵循相同的路径。以下是每个单位的代码（附加在寻路对象上）：

using UnityEngine;using System.Collections;public class Unit : MonoBehaviour {    public Transform target;    float speed = 20;    Vector3[] path;    int targetIndex;void Start() {    PathRequestManager.RequestPath(transform.position,target.position, OnPathFound);}public void OnPathFound(Vector3[] newPath, bool pathSuccessful) {    if (pathSuccessful) {        path = newPath;        StopCoroutine("FollowPath");        StartCoroutine("FollowPath");    }}IEnumerator FollowPath() {    Vector3 currentWaypoint = path[0];    while (true) {        if (transform.position == currentWaypoint) {            targetIndex ++;            if (targetIndex >= path.Length) {                yield break;            }            currentWaypoint = path[targetIndex];        }        transform.position = Vector3.MoveTowards(transform.position,currentWaypoint,speed * Time.deltaTime);        yield return null;    }}public void OnDrawGizmos() {    if (path != null) {        for (int i = targetIndex; i < path.Length; i ++) {            Gizmos.color = Color.black;            Gizmos.DrawCube(path[i], Vector3.one);            if (i == targetIndex) {                Gizmos.DrawLine(transform.position, path[i]);            }            else {                Gizmos.DrawLine(path[i-1],path[i]);            }        }    }}

}

现在如果我尝试通过将void Start()改为void Update()来实现动态路径查找（目标移动，路径更新），这将不起作用。响应会导致单位出现奇怪的行为，如来回移动或无法完成路径等。现在我不知道确切的原因，可能是由于协程的问题？无论如何，我应该如何修改代码以实现正确的动态路径查找？

提前感谢！

P.S. 所有剩余的源代码可以在这里找到： http://bit.ly/pathfindingSource

回答：

我已经“修复”了这个问题，目前有一个足够好的解决方案。

首先，我通过在每个路径点请求新的路径来使路径查找动态化。其次，即使到达目标后，路径查找也会继续进行，通过一些逻辑在每帧检查单位是否再次足够远以重复协程。如果是，则停止旧的协程并启动新的协程。

以下是代码：

using UnityEngine;using System.Collections;public class Unit : MonoBehaviour {public Transform target;float speed = 20;Vector3[] path;int targetIndex;bool  newRequestReady;void Start() {    PathRequestManager.RequestPath(transform.position,target.position, OnPathFound);    newRequestReady = false;}void Update(){    float distance = Vector3.Distance (transform.position, target.position);    Debug.Log(distance);    if(distance < 5){        StopCoroutine("FollowPath");        newRequestReady = true;    }    else if(distance >=10 && newRequestReady){        PathRequestManager.RequestPath(transform.position,target.position, OnPathFound);        StopCoroutine("FollowPath");        newRequestReady = false;    }}public void OnPathFound(Vector3[] newPath, bool pathSuccessful) {    if (pathSuccessful) {        path = newPath;        StopCoroutine("FollowPath");        StartCoroutine("FollowPath");    }}IEnumerator FollowPath() {    Vector3 currentWaypoint = path[0];    while (true) {        if (transform.position == currentWaypoint) {            PathRequestManager.RequestPath(transform.position,target.position,OnPathFound);            targetIndex=0;            targetIndex ++;            //Debug.Log(currentWaypoint);            if (targetIndex >= path.Length) {                targetIndex =0;                path = new Vector3[0];            //yield break;            }            currentWaypoint = path[targetIndex];        }            transform.position = Vector3.MoveTowards(transform.position,currentWaypoint,speed * Time.deltaTime);        yield return null;    }}}