unity A*寻路 （二）读取NavMesh数据

上一章节我们已经看了怎么获得NavMesh数据保存为obj

这一章节我们来读取NavMesh数据

首先我们要定义两个结构体

点 和 三角形

为什么不用unity自带的Vector3呢？

相信你们应该已经知道  我们的寻路不能使用浮点运算

这时候我们就要确定一个精度

我这里设置为10000

namespace AStar
{
    public class AStarConfig 
    {
        /// <summary>
        /// 精度
        /// </summary>
        public const int precision = 10000;
    }
}

点结构体：

using UnityEngine;

namespace AStar
{
    /// <summary>
    /// 点.
    /// </summary>
    public struct AStarPonit
    {
        public int x;
        public int y;
        public int z;

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="point"></param>
        public AStarPonit(Vector3 point)
        {
            x = (int)(point.x * AStarConfig.precision);
            y = (int)(point.y * AStarConfig.precision);
            z = (int)(point.z * AStarConfig.precision);
        }
    }
}

三角形结构体：

namespace AStar
{
    /// <summary>
    /// 三角形
    /// </summary>
    public struct AStarTriangle
    {
        //三角形的三个点坐标
        public AStarPonit a;
        public AStarPonit b;
        public AStarPonit c;

        /// <summary>
        /// 三角形重心
        /// </summary>
        public AStarPonit centroid;

        /// <summary>
        /// 构造函数
        /// </summary>
        public AStarTriangle(AStarPonit a, AStarPonit b, AStarPonit c)
        {
            this.a = a;
            this.b = b;
            this.c = c;

            //计算重心
            centroid.x = (a.x + b.x + c.x) / 3;
            centroid.y = (a.y + b.y + c.y) / 3;
            centroid.z = (a.z + b.z + c.z) / 3;
        }
    }
}

我们需要一个类来保存导航网格信息方便 方便算法使用数据

using System.Collections.Generic;

namespace AStar
{
    /// <summary>
    /// 导航网格信息
    /// </summary>
    public class NavMeshInfo
    {
        /// <summary>
        /// 所有的三角形
        /// </summary>
        public List<AStarTriangle> allTriangle = new List<AStarTriangle>();
        /// <summary>
        /// 所有的重心
        /// </summary>
        public List<AStarPonit> allCentroid = new List<AStarPonit>();
        /// <summary>
        /// 三角形索引 key点 .value点构成的所有三角形  正常情况为三个
        /// </summary>
        public Dictionary<AStarPonit, List<AStarTriangle>> pointIndexes = new Dictionary<AStarPonit, List<AStarTriangle>>();
    }
}

读取导航网格信息代码：

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

namespace AStar
{
    public class NavMeshLoad
    {
        List<Vector3> allPoint = new List<Vector3>();

        /// <summary>
        /// 读取导航网格信息
        /// </summary>
        /// <param name="path">路径</param>
        public NavMeshInfo Load(string path)
        {
            List<string> fileInfo = LoadFile(path);

            NavMeshInfo navMeshInfo = ReadInfo(fileInfo);

            return navMeshInfo;
        }

        /// <summary>
        /// 读取文件
        /// </summary>
        /// <param name="path">路径</param>
        List<string> LoadFile(string path)
        {
            StreamReader sr = new StreamReader(path);

            string line;
            List<string> fileInfo = new List<string>();
            while ((line = sr.ReadLine()) != null)
            {
                //一行一行的读取
                //将每一行的内容存入数组链表容器中
                fileInfo.Add(line);
            }
            //关闭流
            sr.Close();
            //销毁流
            sr.Dispose();
            //将数组链表容器返回
            return fileInfo;
        }

        /// <summary>
        /// 读取数据
        /// </summary>
        /// <param name="fileInfo">文件信息</param>
        /// <returns></returns>
        NavMeshInfo ReadInfo(List<string> fileInfo)
        {
            NavMeshInfo navMeshInfo = new NavMeshInfo();

            for (int i = 0; i < fileInfo.Count; i++)
            {
                string str = fileInfo[i];

                string[] Split = str.Split(' ');

                if (Split[0] == "v")
                {
                    allPoint.Add(new Vector3(float.Parse(Split[2]), float.Parse(Split[3]), float.Parse(Split[4])));
                }
                else if (Split[0] == "f")
                {
                    int a = int.Parse(Split[1]);
                    int b = int.Parse(Split[2]);
                    int c = int.Parse(Split[3]);

                    Vector3 aa = allPoint[a - 1];
                    Vector3 bb = allPoint[b - 1];
                    Vector3 cc = allPoint[c - 1];

                    AStarPonit aaa = new AStarPonit(aa);
                    AStarPonit bbb = new AStarPonit(bb);
                    AStarPonit ccc = new AStarPonit(cc);

                    AStarTriangle triangle = new AStarTriangle(aaa, bbb, ccc);

                    navMeshInfo.allCentroid.Add(triangle.centroid);

                    navMeshInfo.allTriangle.Add(triangle);

                    AddPointIndexes(navMeshInfo.pointIndexes, aaa, triangle);
                    AddPointIndexes(navMeshInfo.pointIndexes, bbb, triangle);
                    AddPointIndexes(navMeshInfo.pointIndexes, ccc, triangle);
                }
            }

            return navMeshInfo;
        }

        /// <summary>
        /// 添加顶点索引
        /// </summary>
        /// <param name="navMeshInfo"></param>
        /// <param name="ponit"></param>
        /// <param name="triangle"></param>
        void AddPointIndexes(Dictionary<AStarPonit, List<AStarTriangle>> navMeshInfo, AStarPonit ponit, AStarTriangle triangle)
        {
            if (navMeshInfo.ContainsKey(ponit))
            {
                navMeshInfo[ponit].Add(triangle);
            }
            else
            {
                List<AStarTriangle> list = new List<AStarTriangle>();
                list.Add(triangle);
                navMeshInfo.Add(ponit, list);
            }
        }
    }
}

我们来写个测试代码看下是否能获得：

using UnityEngine;
using AStar;

public class test : MonoBehaviour
{
    void Start()
    {
        NavMeshLoad navMeshLoad = new NavMeshLoad();

        NavMeshInfo navMeshInfo = navMeshLoad.Load(Application.dataPath + "/AStar/obj/test.obj");
    }
}

断点后 我们看navMeshInfo变量  已经可以看到有数据了

链接: https://pan.baidu.com/s/1Y3BDlp506x7_diq7_d48zw 密码: ihvh