Navigation自动寻路技术（一）

写在前面

第一篇：测试工具的定制
Navigation是Unity内置的寻路解决方案

场景图

1

注：蓝色的小旗是路径点。场景已经进行过烘焙，只有烘焙过的场景才能使用Navigation。

正文

• 将路径点组成一个网络进行管理

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

/// <summary>
/// 将路径点组成一个网络进行管理
/// </summary>
[ExecuteInEditMode]
public class AIWallpointNetWork : MonoBehaviour
{

    //路径的显示类型
    public enum NetWorkDisPlayMode
    {
        //不显示
        NONE,
        //所有路径点连接在一起
        CONNECT,
        //两个路径点组成一条路径
        PATH 
    }

    //默认状态
    [HideInInspector]
    public NetWorkDisPlayMode DisPlayMode = NetWorkDisPlayMode.CONNECT;
    
    //存储路径点的列表
    public List<Transform> WallPoints = new List<Transform>();
    
    //PATH模式下的起始路径点
    [HideInInspector]
    public int from = 0;
    
    //PATH模式下的目标路径点
    [HideInInspector]
    public int to = 1;
}

• 声明编辑器类来定制自己的寻路测试工具

注：请将该编辑器类放在Editor目录下

using System.Collections;
using System.Collections.Generic;
using NUnit.Framework.Constraints;
using UnityEngine;
using UnityEditor;
using UnityEngine.AI;
using UnityEngine.Experimental.PlayerLoop;

/// <summary>
/// 该编辑器类定制自己的寻路测试工具
/// </summary>
[CustomEditor(typeof(AIWallpointNetWork))]
public class AIWallpointNetWorkEditor : Editor
{
    //自定义属性面板
    public override void OnInspectorGUI()
    {
        //所选目标
        AIWallpointNetWork network = target as AIWallpointNetWork;

        //定制枚举变量编辑器样式
        network.DisPlayMode =
            (AIWallpointNetWork.NetWorkDisPlayMode) EditorGUILayout.EnumPopup("DisPlayMode", network.DisPlayMode);
        
        //只有在PATH模式下才能操作from,to
        if (network.DisPlayMode == AIWallpointNetWork.NetWorkDisPlayMode.PATH)
        {
            //定制滑动条
            network.from = EditorGUILayout.IntSlider("Start", network.from, 0, network.WallPoints.Count - 1);
            network.to = EditorGUILayout.IntSlider("End", network.to, 0, network.WallPoints.Count - 1);
        }

        //绘制出原有默认的属性面板，当然已经声明了[HideInInspector]的字段不会被绘制，而是进行自定义绘制
        DrawDefaultInspector();
    }

    //自定义场景显示
    private void OnSceneGUI()
    {
        AIWallpointNetWork network = target as AIWallpointNetWork;

        //给所有的路径点在场景中显示名称
        for (int i = 0; i < network.WallPoints.Count; i++)
        {
            if (network.WallPoints[i] != null)
                Handles.Label(network.WallPoints[i].transform.position, "WallPoint" + i.ToString());
        }

        //该数组存储所有路径点的位置信息，由于要实现环形连接，所以要加多一个长度
        Vector3[] LineWallPoints = new Vector3[network.WallPoints.Count + 1];

        //环形连接模式
        if (network.DisPlayMode == AIWallpointNetWork.NetWorkDisPlayMode.CONNECT)
        {
            for (int i = 0; i <= network.WallPoints.Count; i++)
            {
                //最后一个值归零，也就是连接回原点
                int index = i != network.WallPoints.Count ? i : 0;
                if (network.WallPoints[index] != null)
                {
                    LineWallPoints[i] = network.WallPoints[index].position;
                }
                else
                {
                    LineWallPoints[i] = new Vector3(Mathf.Infinity, Mathf.Infinity, Mathf.Infinity);
                }
            }
            //颜色定制
            Handles.color = Color.yellow;
            //开始绘制线条
            Handles.DrawPolyLine(LineWallPoints);
        }

        //PATH模式下，所选的两个路经点会自动绘制出最佳路径，而不是单纯的直线连接
        else
        if(network.DisPlayMode == AIWallpointNetWork.NetWorkDisPlayMode.PATH)
        {
            //导航系统计算的路径
            NavMeshPath Path = new NavMeshPath();

            if (network.WallPoints[network.from] != null && network.WallPoints[network.to] != null)
            {
                //起始点的位置
                Vector3 from = network.WallPoints[network.from].position;
                //目标点的位置
                Vector3 to = network.WallPoints[network.to].position;
                //开始路径计算，路径点存储在corners里
                NavMesh.CalculatePath(from, to, NavMesh.AllAreas, Path);
            }

            //颜色定制，不同模式颜色最好不一样，便于识别
            Handles.color = Color.cyan;
            //开始绘制路线
            Handles.DrawPolyLine(Path.corners);
        }

        
    }
}

效果图

Connect模式下

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Path模式下