这里我就不解释A*算法
如果你还不知道A*算法
网上有很多简单易懂的例子
我发几个我看过的链接
http://www.cnblogs.com/lipan/archive/2010/07/01/1769420.html
https://zhuanlan.zhihu.com/p/24112879
我这里就当你会A*算法
三角网格的A*算法寻路
需要用到多边形方法
这里我引入了一个Polygon库
在一个工具类中调用这个库文件
如果你想自己写这些逻辑或者有更好的库 可以替换
using System.Collections.Generic; using Polygon; namespace AStar { public class AStarTools { /// <summary> /// 判断点在哪个三角形中 /// </summary> /// <param name="point"></param> /// <param name="allAStarTriangle"></param> /// <returns></returns> public static Triangle GetAStarTriangleByPoint(Ponit point, List<Triangle> allAStarTriangle) { if (allAStarTriangle == null) { return new Triangle(); } Point Point = new Point(point.x, point.z); for (int i = 0; i < allAStarTriangle.Count; i++) { Triangle AStarTriangle = allAStarTriangle[i]; List<Point> pointList = new List<Point>(); pointList.Add(new Point(AStarTriangle.a.x, AStarTriangle.a.z)); pointList.Add(new Point(AStarTriangle.b.x, AStarTriangle.b.z)); pointList.Add(new Point(AStarTriangle.c.x, AStarTriangle.c.z)); if (Utility.CheckPointInPolygon(Point, new Polygon.Polygon(pointList))) { return AStarTriangle; } } return new Triangle(); } } }
算法需要用到一些数据 起点 终点 导航网格信息 等等
我统一保存在一个类中
using UnityEngine; namespace AStar { public class AStarData { /// <summary> /// 开始. /// </summary> public Ponit start; /// <summary> /// 终点. /// </summary> public Ponit end; /// <summary> /// 导航网格信息 /// </summary> public NavMeshInfo navMeshInfo; /// <summary> /// 起点所在的三角形 /// </summary> public Triangle startPlace; /// <summary> /// 终点所在的三角形 /// </summary> public Triangle endPlace; /// <summary> /// 起点新建三角形 /// </summary> public Triangle startAStarTriangle; /// <summary> /// 终点新建三角形 /// </summary> public Triangle endAStarTriangle; public bool Init(Ponit start, Ponit end, NavMeshInfo navMeshInfo) { this.start = start; this.end = end; this.navMeshInfo = navMeshInfo; startAStarTriangle = new Triangle(start, start, start); endAStarTriangle = new Triangle(end, end, end); startPlace = AStarTools.GetAStarTriangleByPoint(start, navMeshInfo.allTriangle); endPlace = AStarTools.GetAStarTriangleByPoint(end, navMeshInfo.allTriangle); if (startPlace == new Triangle()) { Debug.Log("起点不在导航网格信息中"); return false; } if (endPlace == new Triangle()) { Debug.Log("终点不在导航网格信息中"); return false; } return true; } } }
最后是我写的A*算法
using System.Collections.Generic; using System.Linq; namespace AStar { public delegate void AStarCallback(List<Ponit> list); public class Pathfinding { /// <summary> /// 数据 /// </summary> AStarData aStarData; /// <summary> /// 待计算列表. /// </summary> List<Triangle> openList; /// <summary> /// 关闭列表. /// </summary> List<Triangle> closeList; /// <summary> /// 父级索引. /// </summary> Dictionary<Triangle, Triangle> parentIndexes; /// <summary> /// G值. /// </summary> Dictionary<Triangle, float> triangle_G; /// <summary> /// H值. /// </summary> Dictionary<Triangle, float> triangle_H; /// <summary> /// F值. /// </summary> Dictionary<Triangle, float> triangle_F; /// <summary> /// 回调. /// </summary> AStarCallback callback; public void Start(Ponit start, Ponit end, NavMeshInfo navMeshInfo, AStarCallback callback) { if (callback == null) { return; } aStarData = new AStarData(); if (aStarData.Init(start, end, navMeshInfo) == false) { return; } this.callback = callback; openList = new List<Triangle>(); closeList = new List<Triangle>(); parentIndexes = new Dictionary<Triangle, Triangle>(); triangle_G = new Dictionary<Triangle, float>(); triangle_H = new Dictionary<Triangle, float>(); triangle_F = new Dictionary<Triangle, float>(); Core(); } /// <summary> /// 核心 /// </summary> void Core() { openList.Add(aStarData.startAStarTriangle); //开始寻路 寻路到终点结束 while (!openList.Contains(aStarData.endAStarTriangle) && openList.Count != 0) { Triangle AStarTriangle = GetOpenListMin(); openList.Remove(AStarTriangle); closeList.Add(AStarTriangle); Explore(AStarTriangle); } List<Triangle> list = new List<Triangle>(); Triangle T = aStarData.endAStarTriangle; while (parentIndexes.ContainsKey(T) && parentIndexes[T] != null) { list.Add(T); T = parentIndexes[T]; } Callback(list); } /// <summary> /// 获取待计算列表中F值最小的一个. /// </summary> /// <returns></returns> Triangle GetOpenListMin() { Triangle AStarTriangle = openList[0]; for (int i = 0; i < openList.Count; i++) { if (GetDictionaryValue(triangle_F, AStarTriangle) > GetDictionaryValue(triangle_F, openList[i])) { AStarTriangle = openList[i]; } } return AStarTriangle; } /// <summary> /// 获取当前三角形周围的三角形. /// </summary> /// <param name="current"></param> /// <param name="end"></param> /// <param name="map"></param> void Explore(Triangle current) { //获取当前三角形所有的邻边三角形 List<Triangle> list = GetRuoundAStarTriangle(current, aStarData); for (int i = 0; i < list.Count; i++) { Triangle AStarTriangle = list[i]; //去掉当前三角形 if (AStarTriangle == current) { continue; } //去掉已经关闭的三角形 if (closeList.Contains(AStarTriangle)) { continue; } //如果不在待检测的集合 则加入待检测集合 if (!openList.Contains(AStarTriangle)) { SetParentIndexes(AStarTriangle, current); SetDictionaryValue(triangle_G, AStarTriangle, GetG(AStarTriangle, current)); SetDictionaryValue(triangle_H, AStarTriangle, GetH(AStarTriangle)); openList.Add(AStarTriangle); } //如果在待检测的集合 则判断是否修改父级 else { float G = GetDictionaryValue(triangle_G, AStarTriangle); float H = GetDictionaryValue(triangle_H, AStarTriangle); float F = GetG(AStarTriangle, current) + GetH(AStarTriangle); if (G + H > F) { SetParentIndexes(AStarTriangle, current); SetDictionaryValue(triangle_G, AStarTriangle, GetG(AStarTriangle, current)); SetDictionaryValue(triangle_H, AStarTriangle, GetH(AStarTriangle)); openList.Remove(AStarTriangle); } } } } /// <summary> /// 获取G值. /// </summary> /// <param name="grid"></param> /// <param name="parent"></param> /// <returns></returns> float GetG(Triangle grid, Triangle parent) { float distance = Ponit.Distance(grid.centroid, parent.centroid); distance += GetDictionaryValue(triangle_G, parent); return distance; } /// <summary> /// 获取H值. /// </summary> /// <param name="grid"></param> /// <param name="end"></param> /// <returns></returns> float GetH(Triangle grid) { float distance = Ponit.Distance(grid.centroid, aStarData.end); return distance; } /// <summary> /// 添加父级索引. /// </summary> /// <param name="current"></param> /// <param name="parent"></param> void SetParentIndexes(Triangle current, Triangle parent) { if (parentIndexes.ContainsKey(current)) { parentIndexes[current] = parent; } else { parentIndexes.Add(current, parent); } } /// <summary> /// 回调 /// </summary> /// <param name="listAStarTriangle"></param> void Callback(List<Triangle> listAStarTriangle) { if (callback == null || listAStarTriangle == null) { return; } listAStarTriangle.Reverse(); List<Ponit> list = new List<Ponit>(); //进距离移动 不超过一个三角形 if (listAStarTriangle.Count == 1) { list.Add(aStarData.end); callback(list); return; } for (int i = 0; i < listAStarTriangle.Count; i++) { list.Add(listAStarTriangle[i].centroid); } callback(list); } /// <summary> /// 获取周围的三角形 /// </summary> /// <param name="current"></param> /// <returns></returns> public static List<Triangle> GetRuoundAStarTriangle(Triangle current, AStarData aStarData) { //该点为开始点 则获取该点三角重心来取值 if (current.a == aStarData.start && current.b == aStarData.start) { current = aStarData.startPlace; } //获取三角形所有的邻边三角形 List<Triangle> list = new List<Triangle>(); list.AddRange(GetListAStarTriangle(current.a, aStarData.navMeshInfo.pointIndexes)); list.AddRange(GetListAStarTriangle(current.b, aStarData.navMeshInfo.pointIndexes)); list.AddRange(GetListAStarTriangle(current.c, aStarData.navMeshInfo.pointIndexes)); //去掉重复的三角形 list = list.Distinct().ToList(); if (list.Contains(aStarData.endPlace)) { list.Add(aStarData.endAStarTriangle); } return list; } /// <summary> /// 获取顶点对应的三角形列表. /// </summary> /// <param name="ponit</param> /// <param name="map"></param> /// <returns></returns> public static List<Triangle> GetListAStarTriangle(Ponit ponit, Dictionary<Ponit, List<Triangle>> pointIndexes) { List<Triangle> list = null; if (pointIndexes == null) { return list; } if (pointIndexes.ContainsKey(ponit)) { list = pointIndexes[ponit]; } return list; } /// <summary> /// 设置字典的值. /// </summary> /// <param name="data"></param> /// <param name="key"></param> /// <param name="value"></param> public static void SetDictionaryValue(Dictionary<Triangle, float> data, Triangle key, float value) { if (data == null) { return; } if (data.ContainsKey(key)) { data[key] = value; } else { data.Add(key, value); } } /// <summary> /// 获取字典的值. /// </summary> /// <param name="data"></param> /// <param name="key"></param> /// <returns></returns> public static float GetDictionaryValue(Dictionary<Triangle, float> data, Triangle key) { if (data == null) { return 0; } if (!data.ContainsKey(key)) { data.Add(key, 0); } return data[key]; } } }
我们创建一个Capsule游戏对象
让他成为我们需要移动的主角
挂上简单的移动代码
using UnityEngine; using System.Collections; using System.Collections.Generic; using AStar; public delegate void CharacterMoveCallback(); /// <summary> /// 角色移动 /// </summary> public class CharacterMove : MonoBehaviour { /// <summary> /// 目标 /// </summary> public Vector3 target; /// <summary> /// 速度 /// </summary> public float speed = 2; /// <summary> /// 目标距离 /// </summary> public float distance = 0.05f; /// <summary> /// 移动经过的点 /// </summary> List<Vector3> points; /// <summary> /// 回调 /// </summary> CharacterMoveCallback callback; private void Awake() { target = transform.position; } public void Move(Ponit vector3, CharacterMoveCallback callback = null) { target = Ponit.Convert(vector3); this.callback = callback; } public void Move(List<Ponit> points, CharacterMoveCallback callback = null) { this.points = new List<Vector3>(); for (int i = 0; i < points.Count; i++) { this.points.Add(Ponit.Convert(points[i])); } this.callback = callback; GetTarget(); } void GetTarget() { if (points != null && points.Count >= 1) { target = points[0]; points.Remove(points[0]); Debug.Log("前进点 ：" + target); } } void Callback() { if (callback != null) { callback(); callback = null; } } void Update() { //当前位置与目标距离小于间距 移动停止 if (Vector3.Distance(target, transform.position) < distance) { Callback(); return; } //获取移动向量; Vector3 vector = target - transform.position; vector = vector.normalized; //移动 transform.position += vector * Time.deltaTime * speed; //如果到达目标点则替换下一个目标 if (Vector3.Distance(target, transform.position) < distance) { GetTarget(); } } }
再挂上一个简单的开始测试代码
using UnityEngine; using AStar; using System.Collections.Generic; public class test : MonoBehaviour { NavMeshInfo navMeshInfo; void Start() { NavMeshLoad navMeshLoad = new NavMeshLoad(); navMeshInfo = navMeshLoad.Load(Application.dataPath + "/AStar/obj/test.obj"); } private void Update() { if (Input.GetMouseButtonUp(0)) { Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition); RaycastHit hit;// if (Physics.Raycast(ray, out hit))//函数是对射线碰撞的检测 { Vector3 Point = hit.point;//得到碰撞点的坐标 Debug.Log("开始点： " + transform.position); Debug.Log("目标点： " + Point); Debug.Log("目标点对象： " + hit.transform.name); Vector3 start = transform.position; Vector3 end = Point; NavMeshHit tmpNavMeshHit; if (NavMesh.SamplePosition(start, out tmpNavMeshHit, 5.0f, NavMesh.AllAreas)) { start = tmpNavMeshHit.position; } Debug.Log("修改后 开始点： " + start); StartNavigation(start, end, navMeshInfo); } } } public void StartNavigation(Vector3 start, Vector3 end, NavMeshInfo navMeshInfo) { if (navMeshInfo == null) { return; } Pathfinding pathfinding = new Pathfinding(); Ponit startPonit = new Ponit(start); Ponit endPonit = new Ponit(end); pathfinding.Start(startPonit, endPonit, navMeshInfo, (List<Ponit> list) => { CharacterMove controller = GetComponent<CharacterMove>(); controller.Move(list, () => { Debug.Log("寻路结束"); }); }); } }
运行 点击地面 就可以看到Capsule寻路自动行走了
工程下载：
链接: https://pan.baidu.com/s/1qY_zUrqIHB6W4K8wC3PxWQ 密码: iipb