上一节讲到的客户端使用Unity 自带的 NavMesh 来做寻路 3D寻路系统NavMesh-客户端篇。然而，怪物的刷新、移动，和AI是由服务器负责的，怪物的寻路是由服务器控制的，或者像SLG，大地图寻路在玩家离线的情况下要继续寻路，这必须要服务器来主导寻路。
那么，这怎么去实现呢？
我们服务器必须要有一份导航网格的寻路数据。
用ExportSceneToObj 工具导出场景，这个好像不依赖于烘焙出来的导航网格。
//TODO 贴一下源码:
第一份源码是不依赖于导航网格的生成工具：
using System.IO;
using System.Text;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;
public class ExportScene : EditorWindow
{
private const string CUT_LB_OBJ_PATH = "export/bound_lb";
private const string CUT_RT_OBJ_PATH = "export/bound_rt";
private static float autoCutMinX = 1000;
private static float autoCutMaxX = 0;
private static float autoCutMinY = 1000;
private static float autoCutMaxY = 0;
private static float cutMinX = 0;
private static float cutMaxX = 0;
private static float cutMinY = 0;
private static float cutMaxY = 0;
private static long startTime = 0;
private static int totalCount = 0;
private static int count = 0;
private static int counter = 0;
private static int progressUpdateInterval = 10000;
[MenuItem("ExportScene/ExportSceneToObj")]
[MenuItem("GameObject/ExportScene/ExportSceneToObj")]
public static void Export()
{
ExportSceneToObj(false);
}
[MenuItem("ExportScene/ExportSceneToObj(AutoCut)")]
[MenuItem("GameObject/ExportScene/ExportSceneToObj(AutoCut)")]
public static void ExportAutoCut()
{
ExportSceneToObj(true);
}
[MenuItem("ExportScene/ExportSelectedObj")]
[MenuItem("GameObject/ExportScene/ExportSelectedObj", priority = 44)]
public static void ExportObj()
{
GameObject selectObj = Selection.activeGameObject;
if (selectObj == null)
{
Debug.LogWarning("Select a GameObject");
return;
}
string path = GetSavePath(false, selectObj);
if (string.IsNullOrEmpty(path)) return;
Terrain terrain = selectObj.GetComponent<Terrain>();
MeshFilter[] mfs = selectObj.GetComponentsInChildren<MeshFilter>();
SkinnedMeshRenderer[] smrs = selectObj.GetComponentsInChildren<SkinnedMeshRenderer>();
Debug.Log(mfs.Length + "," + smrs.Length);
ExportSceneToObj(path, terrain, mfs, smrs, false, false);
}
public static void ExportSceneToObj(bool autoCut)
{
string path = GetSavePath(autoCut, null);
if (string.IsNullOrEmpty(path)) return;
Terrain terrain = UnityEngine.Object.FindObjectOfType<Terrain>();
MeshFilter[] mfs = UnityEngine.Object.FindObjectsOfType<MeshFilter>();
SkinnedMeshRenderer[] smrs = UnityEngine.Object.FindObjectsOfType<SkinnedMeshRenderer>();
ExportSceneToObj(path, terrain, mfs, smrs, autoCut, true);
}
public static void ExportSceneToObj(string path, Terrain terrain, MeshFilter[] mfs,
SkinnedMeshRenderer[] smrs, bool autoCut, bool needCheckRect)
{
int vertexOffset = 0;
string title = "export GameObject to .obj ...";
StreamWriter writer = new StreamWriter(path);
startTime = GetMsTime();
UpdateCutRect(autoCut);
counter = count = 0;
progressUpdateInterval = 5;
totalCount = (mfs.Length + smrs.Length) / progressUpdateInterval;
foreach (var mf in mfs)
{
UpdateProgress(title);
if (mf.GetComponent<Renderer>() != null &&
(!needCheckRect || (needCheckRect && IsInCutRect(mf.gameObject))))
{
ExportMeshToObj(mf.gameObject, mf.sharedMesh, ref writer, ref vertexOffset);
}
}
foreach (var smr in smrs)
{
UpdateProgress(title);
if (!needCheckRect || (needCheckRect && IsInCutRect(smr.gameObject)))
{
ExportMeshToObj(smr.gameObject, smr.sharedMesh, ref writer, ref vertexOffset);
}
}
if (terrain)
{
ExportTerrianToObj(terrain.terrainData, terrain.GetPosition(),
ref writer, ref vertexOffset, autoCut);
}
writer.Close();
EditorUtility.ClearProgressBar();
long endTime = GetMsTime();
float time = (float)(endTime - startTime) / 1000;
Debug.Log("Export SUCCESS:" + path);
Debug.Log("Export Time:" + time + "s");
OpenDir(path);
}
private static void OpenDir(string path)
{
DirectoryInfo dir = Directory.GetParent(path);
int index = path.LastIndexOf("/");
OpenCmd("explorer.exe", dir.FullName);
}
private static void OpenCmd(string cmd, string args)
{
System.Diagnostics.Process.Start(cmd, args);
}
private static string GetSavePath(bool autoCut, GameObject selectObject)
{
string dataPath = Application.dataPath;
string dir = dataPath.Substring(0, dataPath.LastIndexOf("/"));
string sceneName = UnityEngine.SceneManagement.SceneManager.GetActiveScene().name;
string defaultName = "";
if (selectObject == null)
{
defaultName = (autoCut ? sceneName + "(autoCut)" : sceneName);
}
else
{
defaultName = (autoCut ? selectObject.name + "(autoCut)" : selectObject.name);
}
return EditorUtility.SaveFilePanel("Export .obj file", dir, defaultName, "obj");
}
private static long GetMsTime()
{
return System.DateTime.Now.Ticks / 10000;
//return (System.DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000;
}
private static void UpdateCutRect(bool autoCut)
{
cutMinX = cutMaxX = cutMinY = cutMaxY = 0;
if (!autoCut)
{
Vector3 lbPos = GetObjPos(CUT_LB_OBJ_PATH);
Vector3 rtPos = GetObjPos(CUT_RT_OBJ_PATH);
cutMinX = lbPos.x;
cutMaxX = rtPos.x;
cutMinY = lbPos.z;
cutMaxY = rtPos.z;
}
}
private static void UpdateAutoCutRect(Vector3 v)
{
if (v.x < autoCutMinX) autoCutMinX = v.x;
if (v.x > autoCutMaxX) autoCutMaxX = v.x;
if (v.z < autoCutMinY) autoCutMinY = v.z;
if (v.z > autoCutMaxY) autoCutMaxY = v.z;
}
private static bool IsInCutRect(GameObject obj)
{
if (cutMinX == 0 && cutMaxX == 0 && cutMinY == 0 && cutMaxY == 0) return true;
Vector3 pos = obj.transform.position;
if (pos.x >= cutMinX && pos.x <= cutMaxX && pos.z >= cutMinY && pos.z <= cutMaxY)
return true;
else
return false;
}
private static void ExportMeshToObj(GameObject obj, Mesh mesh, ref StreamWriter writer, ref int vertexOffset)
{
Quaternion r = obj.transform.localRotation;
StringBuilder sb = new StringBuilder();
foreach (Vector3 vertice in mesh.vertices)
{
Vector3 v = obj.transform.TransformPoint(vertice);
UpdateAutoCutRect(v);
sb.AppendFormat("v {0} {1} {2}\n", -v.x, v.y, v.z);
}
foreach (Vector3 nn in mesh.normals)
{
Vector3 v = r * nn;
sb.AppendFormat("vn {0} {1} {2}\n", -v.x, -v.y, v.z);
}
foreach (Vector3 v in mesh.uv)
{
sb.AppendFormat("vt {0} {1}\n", v.x, v.y);
}
for (int i = 0; i < mesh.subMeshCount; i++)
{
int[] triangles = mesh.GetTriangles(i);
for (int j = 0; j < triangles.Length; j += 3)
{
sb.AppendFormat("f {1} {0} {2}\n",
triangles[j] + 1 + vertexOffset,
triangles[j + 1] + 1 + vertexOffset,
triangles[j + 2] + 1 + vertexOffset);
}
}
vertexOffset += mesh.vertices.Length;
writer.Write(sb.ToString());
}
private static void ExportTerrianToObj(TerrainData terrain, Vector3 terrainPos,
ref StreamWriter writer, ref int vertexOffset, bool autoCut)
{
int tw = terrain.heightmapResolution;
int th = terrain.heightmapResolution;
Vector3 meshScale = terrain.size;
meshScale = new Vector3(meshScale.x / (tw - 1), meshScale.y, meshScale.z / (th - 1));
Vector2 uvScale = new Vector2(1.0f / (tw - 1), 1.0f / (th - 1));
Vector2 terrainBoundLB, terrainBoundRT;
if (autoCut)
{
terrainBoundLB = GetTerrainBoundPos(new Vector3(autoCutMinX, 0, autoCutMinY), terrain, terrainPos);
terrainBoundRT = GetTerrainBoundPos(new Vector3(autoCutMaxX, 0, autoCutMaxY), terrain, terrainPos);
}
else
{
terrainBoundLB = GetTerrainBoundPos(CUT_LB_OBJ_PATH, terrain, terrainPos);
terrainBoundRT = GetTerrainBoundPos(CUT_RT_OBJ_PATH, terrain, terrainPos);
}
int bw = (int)(terrainBoundRT.x - terrainBoundLB.x);
int bh = (int)(terrainBoundRT.y - terrainBoundLB.y);
int w = bh != 0 && bh < th ? bh : th;
int h = bw != 0 && bw < tw ? bw : tw;
int startX = (int)terrainBoundLB.y;
int startY = (int)terrainBoundLB.x;
if (startX < 0) startX = 0;
if (startY < 0) startY = 0;
Debug.Log(string.Format("Terrian:tw={0},th={1},sw={2},sh={3},startX={4},startY={5}",
tw, th, bw, bh, startX, startY));
float[,] tData = terrain.GetHeights(0, 0, tw, th);
Vector3[] tVertices = new Vector3[w * h];
Vector2[] tUV = new Vector2[w * h];
int[] tPolys = new int[(w - 1) * (h - 1) * 6];
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
Vector3 pos = new Vector3(-(startY + y), tData[startX + x, startY + y], (startX + x));
tVertices[y * w + x] = Vector3.Scale(meshScale, pos) + terrainPos;
tUV[y * w + x] = Vector2.Scale(new Vector2(x, y), uvScale);
}
}
int index = 0;
for (int y = 0; y < h - 1; y++)
{
for (int x = 0; x < w - 1; x++)
{
tPolys[index++] = (y * w) + x;
tPolys[index++] = ((y + 1) * w) + x;
tPolys[index++] = (y * w) + x + 1;
tPolys[index++] = ((y + 1) * w) + x;
tPolys[index++] = ((y + 1) * w) + x + 1;
tPolys[index++] = (y * w) + x + 1;
}
}
count = counter = 0;
progressUpdateInterval = 10000;
totalCount = (tVertices.Length + tUV.Length + tPolys.Length / 3) / progressUpdateInterval;
string title = "export Terrain to .obj ...";
for (int i = 0; i < tVertices.Length; i++)
{
UpdateProgress(title);
StringBuilder sb = new StringBuilder(22);
sb.AppendFormat("v {0} {1} {2}\n", tVertices[i].x, tVertices[i].y, tVertices[i].z);
writer.Write(sb.ToString());
}
for (int i = 0; i < tUV.Length; i++)
{
UpdateProgress(title);
StringBuilder sb = new StringBuilder(20);
sb.AppendFormat("vt {0} {1}\n", tUV[i].x, tUV[i].y);
writer.Write(sb.ToString());
}
for (int i = 0; i < tPolys.Length; i += 3)
{
UpdateProgress(title);
int x = tPolys[i] + 1 + vertexOffset; ;
int y = tPolys[i + 1] + 1 + vertexOffset;
int z = tPolys[i + 2] + 1 + vertexOffset;
StringBuilder sb = new StringBuilder(30);
sb.AppendFormat("f {0} {1} {2}\n", x, y, z);
writer.Write(sb.ToString());
}
vertexOffset += tVertices.Length;
}
private static Vector2 GetTerrainBoundPos(string path, TerrainData terrain, Vector3 terrainPos)
{
var go = GameObject.Find(path);
if (go)
{
Vector3 pos = go.transform.position;
return GetTerrainBoundPos(pos, terrain, terrainPos);
}
return Vector2.zero;
}
private static Vector2 GetTerrainBoundPos(Vector3 worldPos, TerrainData terrain, Vector3 terrainPos)
{
Vector3 tpos = worldPos - terrainPos;
return new Vector2((int)(tpos.x / terrain.size.x * terrain.heightmapResolution),
(int)(tpos.z / terrain.size.z * terrain.heightmapResolution));
}
private static Vector3 GetObjPos(string path)
{
var go = GameObject.Find(path);
if (go)
{
return go.transform.position;
}
return Vector3.zero;
}
private static void UpdateProgress(string title)
{
if (counter++ == progressUpdateInterval)
{
counter = 0;
float process = Mathf.InverseLerp(0, totalCount, ++count);
long currTime = GetMsTime();
float sec = ((float)(currTime - startTime)) / 1000;
string text = string.Format("{0}/{1}({2:f2} sec.)", count, totalCount, sec);
EditorUtility.DisplayProgressBar(title, text, process);
}
}
}
第二份是要基于导航网格的，但生成的效果不大理想,所以没有采用:
/************************************************
* 文件名:ExportNavMesh.cs
* 描述:导出NavMesh数据给服务器使用
* ************************************************/
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System.IO;
using UnityEngine.AI;
using UnityEngine.SceneManagement;
public class ExportNavMesh
{
[MenuItem("NavMesh/Export")]
static void Export()
{
Debug.Log("ExportNavMesh");
NavMeshTriangulation tmpNavMeshTriangulation = NavMesh.CalculateTriangulation();
//新建文件
string tmpPath = Application.dataPath + "/" + UnityEngine.SceneManagement.SceneManager.GetActiveScene().name + ".obj";
StreamWriter tmpStreamWriter = new StreamWriter(tmpPath);
//顶点
for (int i = 0; i < tmpNavMeshTriangulation.vertices.Length; i++)
{
tmpStreamWriter.WriteLine("v " + tmpNavMeshTriangulation.vertices[i].x + " " +
tmpNavMeshTriangulation.vertices[i].y + " " +
tmpNavMeshTriangulation.vertices[i].z);
}
tmpStreamWriter.WriteLine("g pPlane1");
//索引
for (int i = 0; i < tmpNavMeshTriangulation.indices.Length;)
{
tmpStreamWriter.WriteLine("f " + (tmpNavMeshTriangulation.indices[i] + 1) + " " +
(tmpNavMeshTriangulation.indices[i + 1] + 1) + " " +
(tmpNavMeshTriangulation.indices[i + 2] + 1));
i = i + 3;
}
tmpStreamWriter.Flush();
tmpStreamWriter.Close();
Debug.Log("ExportNavMesh Success");
}
}
选中场景，选择菜单,ExportScene–>ExportSelectedObj，会生成一个Main Terrain.obj文件，大概20几M.
然后用recast 工具打开：
选择solomesh,
调整Agent下Radius参数，与当前项目中 最大寻路单位的半径 保持一致，点击 Build ，等待一段时间后，中间渲染图形会显示生成后的寻路网格，
蓝色地块就是可通点，可以尝试寻路一下。原始的recast是没有开始点和结束点的坐标的，那如何能显示出来呢？
void NavMeshTesterTool::handleRenderOverlay(double* proj, double* model, int* view)
{
GLdouble x, y, z;
char buf[64];
// Draw start and end point labels
if (m_sposSet && gluProject((GLdouble)m_spos[0], (GLdouble)m_spos[1], (GLdouble)m_spos[2],
model, proj, view, &x, &y, &z))
{
if (m_showCoord)
{
snprintf(buf, sizeof(buf), "Start (%.1f, %.1f, %.1f)", m_spos[0], m_spos[1], m_spos[2]);
imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
}
else
imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, "Start", imguiRGBA(0, 0, 0, 220));
}
if (m_toolMode == TOOLMODE_RAYCAST && m_hitResult && m_showCoord &&
gluProject((GLdouble)m_hitPos[0], (GLdouble)m_hitPos[1], (GLdouble)m_hitPos[2],
model, proj, view, &x, &y, &z))
{
snprintf(buf, sizeof(buf), "HitPos (%.1f, %.1f, %.1f)", m_hitPos[0], m_hitPos[1], m_hitPos[2]);
imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
}
if (m_eposSet && gluProject((GLdouble)m_epos[0], (GLdouble)m_epos[1], (GLdouble)m_epos[2],
model, proj, view, &x, &y, &z))
{
if (m_showCoord)
{
float totalCost = 0.0f;
for (int i = 0; i + 1 < m_nstraightPath; i++)
totalCost += dtVdist(&m_straightPath[i * 3], &m_straightPath[(i + 1) * 3]);
snprintf(buf, sizeof(buf), "End (%.1f, %.1f, %.1f), Cost %.1f", m_epos[0], m_epos[1], m_epos[2], totalCost);
imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, buf, imguiRGBA(0, 0, 0, 220));
}
else
imguiDrawText((int)x, (int)(y - 25), IMGUI_ALIGN_CENTER, "End", imguiRGBA(0, 0, 0, 220));
}
}
那么，如何能显示出关键点point list?，首先，路径搜索的模式要改成TOOLMODE_PATHFIND_STRAIGHT模式，代码需要增加如下的打印，
在NavMeshTesterTool.cpp中增加，
void NavMeshTesterTool::recalc(){
....
....
if (m_toolMode == TOOLMODE_PATHFIND_STRAIGHT) {
m_sample->getContext()->log(RC_LOG_PROGRESS, "total point size=%d", m_nstraightPath);
for (int i = 0; i < m_nstraightPath; ++i)
{
m_sample->getContext()->log(RC_LOG_PROGRESS, "(%.1f, %.1f, %.1f)", m_straightPath[i * 3], m_straightPath[i * 3 + 1], m_straightPath[i * 3 + 2]);
}
}
}在Sample.h中增加
public:
Sample();
virtual ~Sample();
void setContext(BuildContext* ctx) { m_ctx = ctx; }
BuildContext* getContext() {
return m_ctx;
}
寻路结果为：
点击 save ，会在当前目录下生成【导出文件】 solo_navmesh.bin，只有156KB,就是服务器导航需要的bin文件。
引入第三方库：
基于recast4j封装的Java版本3D游戏寻路组件
<dependency>
<groupId>com.github.silencesu</groupId>
<artifactId>Easy3dNav</artifactId>
<version>1.1.0</version>
</dependency>
Easy3dNav javaNav = new Easy3dNav();
javaNav.setPrintMeshInfo(false);
javaNav.setUseU3dData(false);
javaNav .init(id, "../../../../game_data/server/navmesh/solo_navmesh.bin");
List<float[]> array = javaNav.find(new float[]{-107.4f, 0f, 148.5f}, new float[]{-51.7f, 0.2f, 150f}, new float[]{1.f, 1.f, 1.f});
执行结果为:
point 5 array=[[-107.4, 0.3209684, 148.5], [-64.09999, 1.2, 137.40001], [-56.299988, 0.6, 139.8], [-54.5, 0.6, 142.5], [-51.7, 0.4, 150.0]]
与工具生成的一致。
以上是JAVA版本的服务器寻路，如何用JNI制作更高性能的寻路包呢，下一篇文章中会做说明。
如果用工具寻路出来的数据和程序寻路出来的数据一致，说明navmesh寻路成功。
接下去就是动态寻路，优化寻路结果。
相关参考：
ExportSceneToObjRecast & Detour将Unity场景（包含物件和地形）导出到.obj文件
Easy3dNav
