Unity3d利用A*寻路算法实现寻路模拟

https://www.geek-share.com/detail/2720697758.html

【Unity】【C#】A*寻路算法-学习心得

https://blog.csdn.net/Terrell21/article/details/82584634

自己实现效果

设置point点

[code]using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Point
{

public Point Parent { get; set; }//父
public float F { get; set; }
public float G { get; set; }
public float H { get; set; }

public int X { get; set; }
public int Y { get; set; }
/// <summary>
/// 是否是障碍物
/// </summary>
public bool IsWall { get; set; }
/// <summary>
/// 构造 初始化
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="parent"></param>
public Point(int x, int y, Point parent = null)
{
this.X = x;
this.Y = y;
this.Parent = parent;
this.IsWall = false;
}

/// <summary>
/// 更新父亲
/// </summary>
/// <param name="parent"></param>
/// <param name="g"></param>
public void UpdateParent(Point parent, float g)
{
this.Parent = parent;
this.G = g;
this.F = G + H;

}
}

A*寻路算法实现

[code]using System.Collections.Generic;
using UnityEngine;

public class AStart : MonoBehaviour
{

private const int mapWhith = 8;
private const int mapHight = 6;
private Point[,] map = new Point[mapWhith, mapHight];//二维数组

// Use this for initialization
void Start()
{
InitMap();
Point start = map[2, 3];//开始点
Point end = map[6, 3];//结束点
FindPath(start, end);
ShowPath(start, end);
//List<Point> l = GetSurroundPoints(new Point(3, 3));
//foreach (var item in l)
//{
//    Debug.Log(item.X + "-" + item.Y);
//}
}
/// <summary>
/// 构建虚拟地图
/// </summary>
private void InitMap()
{
for (int x = 0; x < mapWhith; x++)
{
for (int y = 0; y < mapHight; y++)
{
map[x, y] = new Point(x, y);
}
}
//设置障碍物
map[4, 2].IsWall = true;
map[4, 3].IsWall = true;
map[4, 4].IsWall = true;

}

/// <summary>
/// 现实路径
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
public void ShowPath(Point start, Point end)
{
Point temp = end;
while (true)
{
Debug.Log(temp.X + "--" + temp.Y);

CreateCube(temp.X, temp.Y, Color.red);
if (temp.Parent == null)
{
break;
}
temp = temp.Parent;
}

for (int x = 0; x < mapWhith; x++)
{
for (int y = 0; y < mapHight; y++)
{
if (map[x, y].IsWall == true)
{
CreateCube(x, y, Color.gray);
}
}
}

}

public void CreateCube(float x, float y, Color color)
{
GameObject go = GameObject.CreatePrimitive(PrimitiveType.Cube);
go.transform.position = new Vector3(x, y, 0);
go.GetComponent<MeshRenderer>().material.color = color;
}
/// <summary>
///  路径的计算
/// </summary>
/// <param name="start">开始点</param>
/// <param name="end">结束点</param>
private void FindPath(Point start, Point end)
{
List<Point> openList = new List<Point>();//开始集合
List<Point> closeList = new List<Point>();//关闭集合
openList.Add(start);                      //将开始点加入集合

///这个while有两个终止条件 1，openlist为空  2， 找到目标位置
//在开集合找到距离最短的点  F最小
while (openList.Count > 0)
{
Point point = FindMinFPoint(openList);//找到最小的F
openList.Remove(point);             //在开集合中移除
closeList.Add(point);               //在关集合中添加
List<Point> surroundPoints = GetSurroundPoints(point);//得到周围点的集合
PointsFilter(surroundPoints, closeList);//检查集合是否在闭 在关闭列表就不往开启列表添加数据了
foreach (Point surroundPoint in surroundPoints)
{
if (openList.IndexOf(surroundPoint) > -1)
{
float nowG = CalcG(surroundPoint, point);//更新G值，加上父的G值
if (nowG < surroundPoint.G)
{
surroundPoint.UpdateParent(point, nowG);//更新父亲
}
}
else
{
surroundPoint.Parent = point;//设置父亲
CalcF(surroundPoint, end);//计算F值
openList.Add(surroundPoint);//加入开集合
}
}
// 判断结束条件  判断end 是否在结束列表中
if (openList.IndexOf(end) > -1)
{
break;
}

}
}

/// <summary>
/// 检查集合是否在关闭列表中 （目的）如果 在关闭列表就不往开启列表添加数据了
/// </summary>
/// <param name="src"> 需要检查的集合</param>
/// <param name="closePoint">  已经加入关闭列表的集合</param>
/// <returns></returns>
private void PointsFilter(List<Point> src, List<Point> closePoint)
{
foreach (Point p in closePoint)
{
if (src.IndexOf(p) > -1)//若p不存在，返回-1   src.IndexOf(p) > -1
{
src.Remove(p);
}
}
}

/// <summary>
/// 返回一个点附近的点的集合
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
public List<Point> GetSurroundPoints(Point point)
{
Point up = null, down = null, left = null, right = null;
Point lu = null, ru = null, ld = null, rd = null;
//上、下
if (point.Y < mapHight - 1)        //边界判断，
{
up = map[point.X, point.Y + 1];
}
if (point.Y > 0)
{
down = map[point.X, point.Y - 1];
}
//左、右
if (point.X > 0)
{
left = map[point.X - 1, point.Y];
}
if (point.X < mapWhith - 1)
{
right = map[point.X + 1, point.Y];
}
//左上、右上
if (up != null && left != null)
{
lu = map[point.X - 1, point.Y + 1];
}
if (up != null && right != null)
{
ru = map[point.X + 1, point.Y + 1];
}
//左下，右下
if (down != null && left != null)
{
ld = map[point.X - 1, point.Y - 1];
}
if (down != null && right != null)
{
rd = map[point.X + 1, point.Y - 1];
}
//将可到达的点加入集合
List<Point> list = new List<Point>();
//上下左右
if (down != null && down.IsWall == false)
{
list.Add(down);
}
if (up != null && up.IsWall == false)
{
list.Add(up);
}
if (left != null && left.IsWall == false)
{
list.Add(left);
}
if (right != null && right.IsWall == false)
{
list.Add(right);
}
//四个斜角
if (lu != null && lu.IsWall == false && left.IsWall == false && up.IsWall == false)
{
list.Add(lu);
}
if (ld != null && ld.IsWall == false && left.IsWall == false && down.IsWall == false)
{
list.Add(ld);
}
if (ru != null && ru.IsWall == false && right.IsWall == false && up.IsWall == false)
{
list.Add(ru);
}
if (rd != null && rd.IsWall == false && right.IsWall == false && down.IsWall == false)
{
list.Add(rd);
}
return list;

}

/// <summary>
/// 找寻Point最小的F值
/// </summary>
/// <param name="openList"></param>
/// <returns></returns>
private Point FindMinFPoint(List<Point> openList)
{
float f = float.MaxValue;//设置最大值
Point temp = null;
foreach (Point p in openList)
{
if (p.F < f)
{
temp = p;
f = p.F;
}
}
return temp;
}
/// <summary>
/// 计算G值
/// </summary>
/// <param name="now"></param>
/// <param name="parent"></param>
/// <returns></returns>
public float CalcG(Point now, Point parent)
{
return Vector2.Distance(new Vector2(now.X, now.Y), new Vector2(parent.X, parent.Y)) + parent.G;
}

/// <summary>
/// 计算F值
/// </summary>
/// <param name="now"></param>
/// <param name="end"></param>
private void CalcF(Point now, Point end)
{
// F  =  G  +  H
// 求得F值
float h = Mathf.Abs(end.X - now.X) + Mathf.Abs(end.Y - now.Y);
//预计到达目标点的距离
float g = 0;
if (now.Parent == null)//即为开始点
{
g = 0;
}
else
{
g = Vector2.Distance(new Vector2(now.X, now.Y), new Vector2(now.Parent.X, now.Parent.Y)) + now.Parent.G;
}

float f = g + h;
now.F = f;
now.G = g;
now.H = h;

}
}

最终效果