unity terrain export to obj

最新推荐文章于 2025-05-23 12:19:25 发布
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本文介绍了一个Unity编辑器窗口脚本，用于将地形数据导出为OBJ文件格式。脚本提供了选择导出格式（三角形或四边形）及分辨率选项的功能。
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    import System.IO;
    import System.Text;
    enum SaveFormat {Triangles, Quads}
    enum SaveResolution {Full, Half, Quarter, Eighth, Sixteenth}
    class ExportTerrain extends EditorWindow {
        var saveFormat = SaveFormat.Triangles;
        var saveResolution = SaveResolution.Half;
        static var terrain : TerrainData;
        static var terrainPos : Vector3;

        var tCount : int;
        var counter : int;
        var totalCount : int;

            @MenuItem ("Terrain/Export To Obj...")
        static function Init () {
            terrain = null;
            var terrainObject : Terrain = Selection.activeObject as Terrain;
            if (!terrainObject) {
                terrainObject = Terrain.activeTerrain;
            }
            if (terrainObject) {
                terrain = terrainObject.terrainData;
                terrainPos = terrainObject.transform.position;
            }
            EditorWindow.GetWindow(ExportTerrain).Show();
        }

        function OnGUI () {
            if (!terrain) {
                GUILayout.Label("No terrain found");
                if (GUILayout.Button("Cancel")) {
                    EditorWindow.GetWindow(ExportTerrain).Close();
                }
                return;
            }
            saveFormat = EditorGUILayout.EnumPopup("Export Format", saveFormat);
            saveResolution = EditorGUILayout.EnumPopup("Resolution", saveResolution);

            if (GUILayout.Button("Export")) {
                Export();
            }
        }

        function Export () {
            var fileName = EditorUtility.SaveFilePanel("Export .obj file", "", "Terrain", "obj");
            var w = terrain.heightmapWidth;
            var h = terrain.heightmapHeight;
            var meshScale = terrain.size;
            var tRes = Mathf.Pow(2, parseInt(saveResolution));
            meshScale = Vector3(meshScale.x/(w-1)*tRes, meshScale.y, meshScale.z/(h-1)*tRes);
            var uvScale = Vector2(1.0/(w-1), 1.0/(h-1));
            var tData = terrain.GetHeights(0, 0, w, h);

            w = (w-1) / tRes + 1;
            h = (h-1) / tRes + 1;
            var tVertices = new Vector3[w * h];
            var tUV = new Vector2[w * h];
            if (saveFormat == SaveFormat.Triangles) {
                var tPolys = new int[(w-1) * (h-1) * 6];
            }
            else {
                tPolys = new int[(w-1) * (h-1) * 4];
            }

            // Build vertices and UVs
            for (y = 0; y < h; y++) {
                for (x = 0; x < w; x++) {
                    tVertices[y*w + x] = Vector3.Scale(meshScale, Vector3(x, tData[x*tRes,y*tRes], y)) + terrainPos;
                    tUV[y*w + x] = Vector2.Scale(Vector2(x*tRes, y*tRes), uvScale);
                }
            }

            var index = 0;
            if (saveFormat == SaveFormat.Triangles) {
                // Build triangle indices: 3 indices into vertex array for each triangle
                for (y = 0; y < h-1; y++) {
                    for (x = 0; x < w-1; x++) {
                        // For each grid cell output two triangles
                        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;
                    }
                }
            }
            else {
                // Build quad indices: 4 indices into vertex array for each quad
                for (y = 0; y < h-1; y++) {
                    for (x = 0; x < w-1; x++) {
                        // For each grid cell output one quad
                        tPolys[index++] = (y     * w) + x;
                        tPolys[index++] = ((y+1) * w) + x;
                        tPolys[index++] = ((y+1) * w) + x + 1;
                        tPolys[index++] = (y     * w) + x + 1;
                    }
                }  
            }

            // Export to .obj
            try {
                var sw = new StreamWriter(fileName);
                sw.WriteLine("# Unity terrain OBJ File");

                // Write vertices
                System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
                counter = tCount = 0;
                totalCount = (tVertices.Length*2 + (saveFormat == SaveFormat.Triangles? tPolys.Length/3 : tPolys.Length/4)) / 1000;
                for (i = 0; i < tVertices.Length; i++) {
                    UpdateProgress();
                    var sb = StringBuilder("v ", 20);
                    // StringBuilder stuff is done this way because it's faster than using the "{0} {1} {2}"etc. format
                    // Which is important when you're exporting huge terrains.
                    sb.Append(tVertices[i].x.ToString()).Append(" ").
                       Append(tVertices[i].y.ToString()).Append(" ").
                       Append(tVertices[i].z.ToString());
                    sw.WriteLine(sb);
                }
                // Write UVs
                for (i = 0; i < tUV.Length; i++) {
                    UpdateProgress();
                    sb = StringBuilder("vt ", 22);
                    sb.Append(tUV[i].x.ToString()).Append(" ").
                   Append(tUV[i].y.ToString());
                    sw.WriteLine(sb);
                }
                if (saveFormat == SaveFormat.Triangles) {
                    // Write triangles
                    for (i = 0; i < tPolys.Length; i += 3) {
                        UpdateProgress();
                        sb = StringBuilder("f ", 43);
                        sb.Append(tPolys[i]+1).Append("/").Append(tPolys[i]+1).Append(" ").
                      Append(tPolys[i+1]+1).Append("/").Append(tPolys[i+1]+1).Append(" ").
                       Append(tPolys[i+2]+1).Append("/").Append(tPolys[i+2]+1);
                        sw.WriteLine(sb);
                    }
                }
                else {
                    // Write quads
                    for (i = 0; i < tPolys.Length; i += 4) {
                        UpdateProgress();
                        sb = StringBuilder("f ", 57);
                        sb.Append(tPolys[i]+1).Append("/").Append(tPolys[i]+1).Append(" ").
                               Append(tPolys[i+1]+1).Append("/").Append(tPolys[i+1]+1).Append(" ").
                               Append(tPolys[i+2]+1).Append("/").Append(tPolys[i+2]+1).Append(" ").
                               Append(tPolys[i+3]+1).Append("/").Append(tPolys[i+3]+1);
                        sw.WriteLine(sb);
                    }      
                }
            }
            catch (err) {
                Debug.Log("Error saving file: " + err.Message);
            }
            sw.Close();

            terrain = null;
            EditorUtility.ClearProgressBar();
            EditorWindow.GetWindow(ExportTerrain).Close();
        }

        function UpdateProgress () {
            if (counter++ == 1000) {
                counter = 0;
                EditorUtility.DisplayProgressBar("Saving...", "", Mathf.InverseLerp(0, totalCount, ++tCount));
            }
        }
    }