Unity3d开发（十三）导出NavMesh可行走区域信息

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文章作者：松阳

本文出自 阿修罗道，禁止用于商业用途，转载请注明出处。  

原文链接：http://blog.csdn.net/fansongy/article/details/51699058

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有时我们会需要Unity3d的地图信息，比如A*之类的逻辑运算。当这些操作要放到服务器上进行时，就需要地图信息。通常项目中的行走区域是使用Navmesh制作的。这篇文章中，介绍如何将Navmesh的信息导出成bitmap。

脚本效果

整个工具的设置界面放到Inspector中，由于是程序同学用，所以界面就比较糙，对付用吧 可以设置几个数值，导出地图的左顶点坐标、地图精度、宽、高，设置界面如下图所示：

设置好后点击Export按钮，即可在场景中计算出可行走区域：

可以看到，与Navmesh的可行走区域相对应位置会画出绿色标尺线，不能行走则标为红色。最终导出的信息内容如下：

startpos=(-6.0, 0.0, 6.0)height=15wide=15accuracy=1{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,0,0,0,0,1,0,0,0,0,},{0,0,1,1,1,1,0,0,0,0,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,},{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,},

核心原理

使用一个Unity3d中Navmesh的接口：

NavMesh.SamplePosition

来检测一个点是否在可行走区域中。同时将内容输出到日志中。检测时增加了不同高度的采样，防止由于斜坡引起的遗漏。

代码实现

using UnityEngine;using System.Collections;using System.Text;using UnityEditor;public class NavExport : MonoBehaviour{    #region Public Attributes    public Vector3 leftUpStart = Vector3.zero;    public float accuracy = 1;    public int height = 30;    public int wide = 30;    #endregion    #region Unity Messages    void OnGUI()    {        if (GUILayout.Button("Export"))        {            exportPoint(leftUpStart, height, wide, accuracy);        }    }    #endregion    #region Public Methods    public void Exp()    {        exportPoint(leftUpStart, wide, height, accuracy);    }    public void exportPoint(Vector3 startPos, int x, int y, float accuracy)    {        StringBuilder str = new StringBuilder();        int[,] list = new int[x, y];        str.Append("startpos=").Append(startPos).Append("\r\n");        str.Append("height=").Append(y).Append("\r\nwide=").Append(x).Append("\r\naccuracy=").Append(accuracy).Append("\r\n");        for (int i = 0; i < y; ++i)        {            str.Append("{");            for (int j = 0; j < x; ++j)            {                int res = list[j, i];                NavMeshHit hit;                for (int k = -10; k < 30; ++k)                {                    if (NavMesh.SamplePosition(startPos + new Vector3(j * accuracy, k, -i * accuracy), out hit, 0.2f, NavMesh.AllAreas))                    {                        res = 1;                        break;                    }                }                Debug.DrawRay(startPos + new Vector3(j * accuracy, 0, -i * accuracy), Vector3.up, res == 1 ? Color.green : Color.red, 5);                str.Append(res).Append(",");            }            str.Append("},\n");        }        Debug.Log(str.ToString());    }    #endregion}[CustomEditor(typeof(NavExport))]public class NavExportHelper : Editor{    public override void OnInspectorGUI()    {        base.OnInspectorGUI();        if (GUILayout.Button("Export"))        {            var exp = target as NavExport;            exp.Exp();        }    }}

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