simgear/scene/tgdb/obj.cxx

   1 // obj.cxx -- routines to handle loading scenery and building the plib
   2 //            scene graph.
   3 //
   4 // Written by Curtis Olson, started October 1997.
   5 //
   6 // Copyright (C) 1997  Curtis L. Olson  - http://www.flightgear.org/~curt
   7 //
   8 // This program is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU General Public License as
  10 // published by the Free Software Foundation; either version 2 of the
  11 // License, or (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful, but
  14 // WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  21 //
  22 // $Id$
  23
  24
  25 #ifdef HAVE_CONFIG_H
  26 #  include <simgear_config.h>
  27 #endif
  28
  29 #include "obj.hxx"
  30
  31 #include <simgear/compiler.h>
  32
  33 #include <osg/Fog>
  34 #include <osg/Geode>
  35 #include <osg/Geometry>
  36 #include <osg/Group>
  37 #include <osg/LOD>
  38 #include <osg/MatrixTransform>
  39 #include <osg/Point>
  40 #include <osg/StateSet>
  41 #include <osg/Switch>
  42
  43 #include <boost/foreach.hpp>
  44
  45 #include <algorithm>
  46
  47 #include <simgear/debug/logstream.hxx>
  48 #include <simgear/io/sg_binobj.hxx>
  49 #include <simgear/math/sg_geodesy.hxx>
  50 #include <simgear/math/sg_random.h>
  51 #include <simgear/math/SGMisc.hxx>
  52 #include <simgear/scene/material/Effect.hxx>
  53 #include <simgear/scene/material/EffectGeode.hxx>
  54 #include <simgear/scene/material/mat.hxx>
  55 #include <simgear/scene/material/matmodel.hxx>
  56 #include <simgear/scene/material/matlib.hxx>
  57 #include <simgear/scene/model/SGOffsetTransform.hxx>
  58 #include <simgear/scene/util/SGUpdateVisitor.hxx>
  59 #include <simgear/scene/util/SGNodeMasks.hxx>
  60 #include <simgear/scene/util/QuadTreeBuilder.hxx>
  61 #include <simgear/scene/util/SGReaderWriterOptions.hxx>
  62
  63 #include "SGTexturedTriangleBin.hxx"
  64 #include "SGLightBin.hxx"
  65 #include "SGModelBin.hxx"
  66 #include "SGBuildingBin.hxx"
  67 #include "TreeBin.hxx"
  68 #include "SGDirectionalLightBin.hxx"
  69 #include "GroundLightManager.hxx"
  70
  71
  72 #include "pt_lights.hxx"
  73
  74 using namespace simgear;
  75
  76 typedef std::map<std::string,SGTexturedTriangleBin> SGMaterialTriangleMap;
  77 typedef std::list<SGLightBin> SGLightListBin;
  78 typedef std::list<SGDirectionalLightBin> SGDirectionalLightListBin;
  79
  80 struct SGTileGeometryBin {
  81   SGMaterialTriangleMap materialTriangleMap;
  82   SGLightBin tileLights;
  83   SGLightBin randomTileLights;
  84   SGTreeBinList randomForest;
  85   SGDirectionalLightBin runwayLights;
  86   SGDirectionalLightBin taxiLights;
  87   SGDirectionalLightListBin vasiLights;
  88   SGDirectionalLightListBin rabitLights;
  89   SGLightListBin odalLights;
  90   SGDirectionalLightListBin holdshortLights;
  91   SGDirectionalLightListBin guardLights;
  92   SGDirectionalLightListBin reilLights;
  93   SGMatModelBin randomModels;
  94   SGBuildingBinList randomBuildings;
  95
  96   static SGVec4f
  97   getMaterialLightColor(const SGMaterial* material)
  98   {
  99     if (!material)
 100       return SGVec4f(1, 1, 1, 0.8);
 101     return material->get_light_color();
 102   }
 103
 104   static void
 105   addPointGeometry(SGLightBin& lights,
 106                    const std::vector<SGVec3d>& vertices,
 107                    const SGVec4f& color,
 108                    const int_list& pts_v)
 109   {
 110     for (unsigned i = 0; i < pts_v.size(); ++i)
 111       lights.insert(toVec3f(vertices[pts_v[i]]), color);
 112   }
 113
 114   static void
 115   addPointGeometry(SGDirectionalLightBin& lights,
 116                    const std::vector<SGVec3d>& vertices,
 117                    const std::vector<SGVec3f>& normals,
 118                    const SGVec4f& color,
 119                    const int_list& pts_v,
 120                    const int_list& pts_n)
 121   {
 122     // If the normal indices match the vertex indices, use seperate
 123     // normal indices. Else reuse the vertex indices for the normals.
 124     if (pts_v.size() == pts_n.size()) {
 125       for (unsigned i = 0; i < pts_v.size(); ++i)
 126         lights.insert(toVec3f(vertices[pts_v[i]]), normals[pts_n[i]], color);
 127     } else {
 128       for (unsigned i = 0; i < pts_v.size(); ++i)
 129         lights.insert(toVec3f(vertices[pts_v[i]]), normals[pts_v[i]], color);
 130     }
 131   }
 132
 133   bool
 134   insertPtGeometry(const SGBinObject& obj, SGMaterialLib* matlib)
 135   {
 136     if (obj.get_pts_v().size() != obj.get_pts_n().size()) {
 137       SG_LOG(SG_TERRAIN, SG_ALERT,
 138              "Group list sizes for points do not match!");
 139       return false;
 140     }
 141
 142     for (unsigned grp = 0; grp < obj.get_pts_v().size(); ++grp) {
 143       std::string materialName = obj.get_pt_materials()[grp];
 144       SGMaterial* material = 0;
 145       if (matlib)
 146           material = matlib->find(materialName);
 147       SGVec4f color = getMaterialLightColor(material);
 148
 149       if (3 <= materialName.size() && materialName.substr(0, 3) != "RWY") {
 150         // Just plain lights. Not something for the runway.
 151         addPointGeometry(tileLights, obj.get_wgs84_nodes(), color,
 152                          obj.get_pts_v()[grp]);
 153       } else if (materialName == "RWY_BLUE_TAXIWAY_LIGHTS"
 154                  || materialName == "RWY_GREEN_TAXIWAY_LIGHTS") {
 155         addPointGeometry(taxiLights, obj.get_wgs84_nodes(), obj.get_normals(),
 156                          color, obj.get_pts_v()[grp], obj.get_pts_n()[grp]);
 157       } else if (materialName == "RWY_VASI_LIGHTS") {
 158         vasiLights.push_back(SGDirectionalLightBin());
 159         addPointGeometry(vasiLights.back(), obj.get_wgs84_nodes(),
 160                          obj.get_normals(), color, obj.get_pts_v()[grp],
 161                          obj.get_pts_n()[grp]);
 162       } else if (materialName == "RWY_SEQUENCED_LIGHTS") {
 163         rabitLights.push_back(SGDirectionalLightBin());
 164         addPointGeometry(rabitLights.back(), obj.get_wgs84_nodes(),
 165                          obj.get_normals(), color, obj.get_pts_v()[grp],
 166                          obj.get_pts_n()[grp]);
 167       } else if (materialName == "RWY_ODALS_LIGHTS") {
 168         odalLights.push_back(SGLightBin());
 169         addPointGeometry(odalLights.back(), obj.get_wgs84_nodes(),
 170                          color, obj.get_pts_v()[grp]);
 171       } else if (materialName == "RWY_YELLOW_PULSE_LIGHTS") {
 172         holdshortLights.push_back(SGDirectionalLightBin());
 173         addPointGeometry(holdshortLights.back(), obj.get_wgs84_nodes(),
 174                          obj.get_normals(), color, obj.get_pts_v()[grp],
 175                          obj.get_pts_n()[grp]);
 176       } else if (materialName == "RWY_GUARD_LIGHTS") {
 177         guardLights.push_back(SGDirectionalLightBin());
 178         addPointGeometry(guardLights.back(), obj.get_wgs84_nodes(),
 179                          obj.get_normals(), color, obj.get_pts_v()[grp],
 180                          obj.get_pts_n()[grp]);
 181       } else if (materialName == "RWY_REIL_LIGHTS") {
 182         reilLights.push_back(SGDirectionalLightBin());
 183         addPointGeometry(reilLights.back(), obj.get_wgs84_nodes(),
 184                          obj.get_normals(), color, obj.get_pts_v()[grp],
 185                          obj.get_pts_n()[grp]);
 186       } else {
 187         // what is left must be runway lights
 188         addPointGeometry(runwayLights, obj.get_wgs84_nodes(),
 189                          obj.get_normals(), color, obj.get_pts_v()[grp],
 190                          obj.get_pts_n()[grp]);
 191       }
 192     }
 193
 194     return true;
 195   }
 196
 197
 198   static SGVec2f
 199   getTexCoord(const std::vector<SGVec2f>& texCoords, const int_list& tc,
 200               const SGVec2f& tcScale, unsigned i)
 201   {
 202     if (tc.empty())
 203       return tcScale;
 204     else if (tc.size() == 1)
 205       return mult(texCoords[tc[0]], tcScale);
 206     else
 207       return mult(texCoords[tc[i]], tcScale);
 208   }
 209
 210   static void
 211   addTriangleGeometry(SGTexturedTriangleBin& triangles,
 212                       const std::vector<SGVec3d>& vertices,
 213                       const std::vector<SGVec3f>& normals,
 214                       const std::vector<SGVec2f>& texCoords,
 215                       const int_list& tris_v,
 216                       const int_list& tris_n,
 217                       const int_list& tris_tc,
 218                       const SGVec2f& tcScale)
 219   {
 220     if (tris_v.size() != tris_n.size()) {
 221       // If the normal indices do not match, they should be inmplicitly
 222       // the same than the vertex indices. So just call ourselves again
 223       // with the matching index vector.
 224       addTriangleGeometry(triangles, vertices, normals, texCoords,
 225                           tris_v, tris_v, tris_tc, tcScale);
 226       return;
 227     }
 228
 229     for (unsigned i = 2; i < tris_v.size(); i += 3) {
 230       SGVertNormTex v0;
 231       v0.vertex = toVec3f(vertices[tris_v[i-2]]);
 232       v0.normal = normals[tris_n[i-2]];
 233       v0.texCoord = getTexCoord(texCoords, tris_tc, tcScale, i-2);
 234       SGVertNormTex v1;
 235       v1.vertex = toVec3f(vertices[tris_v[i-1]]);
 236       v1.normal = normals[tris_n[i-1]];
 237       v1.texCoord = getTexCoord(texCoords, tris_tc, tcScale, i-1);
 238       SGVertNormTex v2;
 239       v2.vertex = toVec3f(vertices[tris_v[i]]);
 240       v2.normal = normals[tris_n[i]];
 241       v2.texCoord = getTexCoord(texCoords, tris_tc, tcScale, i);
 242       triangles.insert(v0, v1, v2);
 243     }
 244   }
 245
 246   static void
 247   addStripGeometry(SGTexturedTriangleBin& triangles,
 248                    const std::vector<SGVec3d>& vertices,
 249                    const std::vector<SGVec3f>& normals,
 250                    const std::vector<SGVec2f>& texCoords,
 251                    const int_list& strips_v,
 252                    const int_list& strips_n,
 253                    const int_list& strips_tc,
 254                    const SGVec2f& tcScale)
 255   {
 256     if (strips_v.size() != strips_n.size()) {
 257       // If the normal indices do not match, they should be inmplicitly
 258       // the same than the vertex indices. So just call ourselves again
 259       // with the matching index vector.
 260       addStripGeometry(triangles, vertices, normals, texCoords,
 261                        strips_v, strips_v, strips_tc, tcScale);
 262       return;
 263     }
 264
 265     for (unsigned i = 2; i < strips_v.size(); ++i) {
 266       SGVertNormTex v0;
 267       v0.vertex = toVec3f(vertices[strips_v[i-2]]);
 268       v0.normal = normals[strips_n[i-2]];
 269       v0.texCoord = getTexCoord(texCoords, strips_tc, tcScale, i-2);
 270       SGVertNormTex v1;
 271       v1.vertex = toVec3f(vertices[strips_v[i-1]]);
 272       v1.normal = normals[strips_n[i-1]];
 273       v1.texCoord = getTexCoord(texCoords, strips_tc, tcScale, i-1);
 274       SGVertNormTex v2;
 275       v2.vertex = toVec3f(vertices[strips_v[i]]);
 276       v2.normal = normals[strips_n[i]];
 277       v2.texCoord = getTexCoord(texCoords, strips_tc, tcScale, i);
 278       if (i%2)
 279         triangles.insert(v1, v0, v2);
 280       else
 281         triangles.insert(v0, v1, v2);
 282     }
 283   }
 284
 285   static void
 286   addFanGeometry(SGTexturedTriangleBin& triangles,
 287                  const std::vector<SGVec3d>& vertices,
 288                  const std::vector<SGVec3f>& normals,
 289                  const std::vector<SGVec2f>& texCoords,
 290                  const int_list& fans_v,
 291                  const int_list& fans_n,
 292                  const int_list& fans_tc,
 293                  const SGVec2f& tcScale)
 294   {
 295     if (fans_v.size() != fans_n.size()) {
 296       // If the normal indices do not match, they should be implicitly
 297       // the same than the vertex indices. So just call ourselves again
 298       // with the matching index vector.
 299       addFanGeometry(triangles, vertices, normals, texCoords,
 300                      fans_v, fans_v, fans_tc, tcScale);
 301       return;
 302     }
 303
 304     SGVertNormTex v0;
 305     v0.vertex = toVec3f(vertices[fans_v[0]]);
 306     v0.normal = normals[fans_n[0]];
 307     v0.texCoord = getTexCoord(texCoords, fans_tc, tcScale, 0);
 308     SGVertNormTex v1;
 309     v1.vertex = toVec3f(vertices[fans_v[1]]);
 310     v1.normal = normals[fans_n[1]];
 311     v1.texCoord = getTexCoord(texCoords, fans_tc, tcScale, 1);
 312     for (unsigned i = 2; i < fans_v.size(); ++i) {
 313       SGVertNormTex v2;
 314       v2.vertex = toVec3f(vertices[fans_v[i]]);
 315       v2.normal = normals[fans_n[i]];
 316       v2.texCoord = getTexCoord(texCoords, fans_tc, tcScale, i);
 317       triangles.insert(v0, v1, v2);
 318       v1 = v2;
 319     }
 320   }
 321
 322   SGVec2f getTexCoordScale(const std::string& name, SGMaterialLib* matlib)
 323   {
 324     if (!matlib)
 325       return SGVec2f(1, 1);
 326     SGMaterial* material = matlib->find(name);
 327     if (!material)
 328       return SGVec2f(1, 1);
 329
 330     return material->get_tex_coord_scale();
 331   }
 332
 333   bool
 334   insertSurfaceGeometry(const SGBinObject& obj, SGMaterialLib* matlib)
 335   {
 336     if (obj.get_tris_n().size() < obj.get_tris_v().size() ||
 337         obj.get_tris_tc().size() < obj.get_tris_v().size()) {
 338       SG_LOG(SG_TERRAIN, SG_ALERT,
 339              "Group list sizes for triangles do not match!");
 340       return false;
 341     }
 342
 343     for (unsigned grp = 0; grp < obj.get_tris_v().size(); ++grp) {
 344       std::string materialName = obj.get_tri_materials()[grp];
 345       SGVec2f tcScale = getTexCoordScale(materialName, matlib);
 346       addTriangleGeometry(materialTriangleMap[materialName],
 347                           obj.get_wgs84_nodes(), obj.get_normals(),
 348                           obj.get_texcoords(), obj.get_tris_v()[grp],
 349                           obj.get_tris_n()[grp], obj.get_tris_tc()[grp],
 350                           tcScale);
 351     }
 352
 353     if (obj.get_strips_n().size() < obj.get_strips_v().size() ||
 354         obj.get_strips_tc().size() < obj.get_strips_v().size()) {
 355       SG_LOG(SG_TERRAIN, SG_ALERT,
 356              "Group list sizes for strips do not match!");
 357       return false;
 358     }
 359     for (unsigned grp = 0; grp < obj.get_strips_v().size(); ++grp) {
 360       std::string materialName = obj.get_strip_materials()[grp];
 361       SGVec2f tcScale = getTexCoordScale(materialName, matlib);
 362       addStripGeometry(materialTriangleMap[materialName],
 363                        obj.get_wgs84_nodes(), obj.get_normals(),
 364                        obj.get_texcoords(), obj.get_strips_v()[grp],
 365                        obj.get_strips_n()[grp], obj.get_strips_tc()[grp],
 366                        tcScale);
 367     }
 368
 369     if (obj.get_fans_n().size() < obj.get_fans_v().size() ||
 370         obj.get_fans_tc().size() < obj.get_fans_v().size()) {
 371       SG_LOG(SG_TERRAIN, SG_ALERT,
 372              "Group list sizes for fans do not match!");
 373       return false;
 374     }
 375     for (unsigned grp = 0; grp < obj.get_fans_v().size(); ++grp) {
 376       std::string materialName = obj.get_fan_materials()[grp];
 377       SGVec2f tcScale = getTexCoordScale(materialName, matlib);
 378       addFanGeometry(materialTriangleMap[materialName],
 379                      obj.get_wgs84_nodes(), obj.get_normals(),
 380                      obj.get_texcoords(), obj.get_fans_v()[grp],
 381                      obj.get_fans_n()[grp], obj.get_fans_tc()[grp],
 382                      tcScale);
 383     }
 384     return true;
 385   }
 386
 387   osg::Node* getSurfaceGeometry(SGMaterialLib* matlib) const
 388   {
 389     if (materialTriangleMap.empty())
 390       return 0;
 391
 392     EffectGeode* eg = 0;
 393     osg::Group* group = (materialTriangleMap.size() > 1 ? new osg::Group : 0);
 394     //osg::Geode* geode = new osg::Geode;
 395     SGMaterialTriangleMap::const_iterator i;
 396     for (i = materialTriangleMap.begin(); i != materialTriangleMap.end(); ++i) {
 397       osg::Geometry* geometry = i->second.buildGeometry();
 398       SGMaterial *mat = 0;
 399       if (matlib)
 400         mat = matlib->find(i->first);
 401       eg = new EffectGeode;
 402       eg->setName("EffectGeode");
 403       if (mat)
 404         eg->setEffect(mat->get_effect(i->second));
 405       eg->addDrawable(geometry);
 406       eg->runGenerators(geometry);  // Generate extra data needed by effect
 407       if (group) {
 408         group->setName("surfaceGeometryGroup");
 409         group->addChild(eg);
 410       }
 411     }
 412     if (group)
 413         return group;
 414     else
 415         return eg;
 416   }
 417
 418   void computeRandomSurfaceLights(SGMaterialLib* matlib)
 419   {
 420     SGMaterialTriangleMap::iterator i;
 421
 422     // generate a repeatable random seed
 423     mt seed;
 424     mt_init(&seed, unsigned(123));
 425
 426     for (i = materialTriangleMap.begin(); i != materialTriangleMap.end(); ++i) {
 427       SGMaterial *mat = matlib->find(i->first);
 428       if (!mat)
 429         continue;
 430
 431       float coverage = mat->get_light_coverage();
 432       if (coverage <= 0)
 433         continue;
 434       if (coverage < 10000.0) {
 435         SG_LOG(SG_INPUT, SG_ALERT, "Light coverage is "
 436                << coverage << ", pushing up to 10000");
 437         coverage = 10000;
 438       }
 439
 440       std::vector<SGVec3f> randomPoints;
 441       i->second.addRandomSurfacePoints(coverage, 3, mat->get_object_mask(i->second), randomPoints);
 442       std::vector<SGVec3f>::iterator j;
 443       for (j = randomPoints.begin(); j != randomPoints.end(); ++j) {
 444         float zombie = mt_rand(&seed);
 445         // factor = sg_random() ^ 2, range = 0 .. 1 concentrated towards 0
 446         float factor = mt_rand(&seed);
 447         factor *= factor;
 448
 449         float bright = 1;
 450         SGVec4f color;
 451         if ( zombie > 0.5 ) {
 452           // 50% chance of yellowish
 453           color = SGVec4f(0.9f, 0.9f, 0.3f, bright - factor * 0.2f);
 454         } else if (zombie > 0.15f) {
 455           // 35% chance of whitish
 456           color = SGVec4f(0.9, 0.9f, 0.8f, bright - factor * 0.2f);
 457         } else if (zombie > 0.05f) {
 458           // 10% chance of orangish
 459           color = SGVec4f(0.9f, 0.6f, 0.2f, bright - factor * 0.2f);
 460         } else {
 461           // 5% chance of redish
 462           color = SGVec4f(0.9f, 0.2f, 0.2f, bright - factor * 0.2f);
 463         }
 464         randomTileLights.insert(*j, color);
 465       }
 466     }
 467   }
 468
 469   void computeRandomObjectsAndBuildings(
 470     SGMaterialLib* matlib,
 471     float building_density,
 472     bool use_random_objects,
 473     bool use_random_buildings)
 474   {
 475     SGMaterialTriangleMap::iterator i;
 476
 477     // generate a repeatable random seed
 478     mt seed;
 479     mt_init(&seed, unsigned(123));
 480
 481     for (i = materialTriangleMap.begin(); i != materialTriangleMap.end(); ++i) {
 482       SGMaterial *mat = matlib->find(i->first);
 483       SGTexturedTriangleBin triangleBin = i->second;
 484
 485       if (!mat)
 486         continue;
 487
 488       osg::Texture2D* object_mask  = mat->get_object_mask(triangleBin);
 489       int   group_count            = mat->get_object_group_count();
 490       float building_coverage      = mat->get_building_coverage();
 491       float cos_zero_density_angle = mat->get_cos_object_zero_density_slope_angle();
 492       float cos_max_density_angle  = mat->get_cos_object_max_density_slope_angle();
 493
 494       bool found = false;
 495       SGBuildingBin* bin = NULL;
 496
 497       if (building_coverage > 0) {
 498         BOOST_FOREACH(bin, randomBuildings)
 499         {
 500           if (bin->getMaterialName() == mat->get_names()[0]) {
 501               found = true;
 502               break;
 503           }
 504         }
 505
 506         if (!found) {
 507           bin = new SGBuildingBin(mat);
 508           randomBuildings.push_back(bin);
 509         }
 510       }
 511
 512       unsigned num = i->second.getNumTriangles();
 513       int random_dropped = 0;
 514       int mask_dropped = 0;
 515       int building_dropped = 0;
 516       int triangle_dropped = 0;
 517
 518       for (unsigned i = 0; i < num; ++i) {
 519         SGTexturedTriangleBin::triangle_ref triangleRef = triangleBin.getTriangleRef(i);
 520
 521         SGVec3f vorigin = triangleBin.getVertex(triangleRef[0]).vertex;
 522         SGVec3f v0 = triangleBin.getVertex(triangleRef[1]).vertex - vorigin;
 523         SGVec3f v1 = triangleBin.getVertex(triangleRef[2]).vertex - vorigin;
 524         SGVec2f torigin = triangleBin.getVertex(triangleRef[0]).texCoord;
 525         SGVec2f t0 = triangleBin.getVertex(triangleRef[1]).texCoord - torigin;
 526         SGVec2f t1 = triangleBin.getVertex(triangleRef[2]).texCoord - torigin;
 527         SGVec3f normal = cross(v0, v1);
 528
 529         // Ensure the slope isn't too steep by checking the
 530         // cos of the angle between the slope normal and the
 531         // vertical (conveniently the z-component of the normalized
 532         // normal) and values passed in.
 533         float cos = normalize(normal).z();
 534         float slope_density = 1.0;
 535         if (cos < cos_zero_density_angle) continue; // Too steep for any objects
 536         if (cos < cos_max_density_angle) {
 537           slope_density =
 538             (cos - cos_zero_density_angle) /
 539             (cos_max_density_angle - cos_zero_density_angle);
 540         }
 541
 542         // Containers to hold the random buildings and objects generated
 543         // for this triangle for collision detection purposes.
 544         std::vector< std::pair< SGVec3f, float> > triangleObjectsList;
 545         std::vector< std::pair< SGVec3f, float> > triangleBuildingList;
 546
 547         // Compute the area
 548         float area = 0.5f*length(normal);
 549         if (area <= SGLimitsf::min())
 550           continue;
 551
 552         // Generate any random objects
 553         if (use_random_objects && (group_count > 0))
 554         {
 555           for (int j = 0; j < group_count; j++)
 556           {
 557             SGMatModelGroup *object_group =  mat->get_object_group(j);
 558             int nObjects = object_group->get_object_count();
 559
 560             if (nObjects == 0) continue;
 561
 562             // For each of the random models in the group, determine an appropriate
 563             // number of random placements and insert them.
 564             for (int k = 0; k < nObjects; k++) {
 565               SGMatModel * object = object_group->get_object(k);
 566
 567               // Determine the number of objecst to place, taking into account
 568               // the slope density factor.
 569               double n = slope_density * area / object->get_coverage_m2();
 570
 571               // Use the zombie door method to determine fractional object placement.
 572               n = n + mt_rand(&seed);
 573
 574               // place an object each unit of area
 575               while ( n > 1.0 ) {
 576                 float a = mt_rand(&seed);
 577                 float b = mt_rand(&seed);
 578                 if ( a + b > 1 ) {
 579                   a = 1 - a;
 580                   b = 1 - b;
 581                 }
 582
 583                 SGVec3f randomPoint = vorigin + a*v0 + b*v1;
 584                 float rotation = static_cast<float>(mt_rand(&seed));
 585
 586                 // Check that the point is sufficiently far from
 587                 // the edge of the triangle by measuring the distance
 588                 // from the three lines that make up the triangle.
 589                 float spacing = object->get_spacing_m();
 590
 591                 SGVec3f p = randomPoint - vorigin;
 592                 float edges[] = { length(cross(p     , p - v0)) / length(v0),
 593                                   length(cross(p - v0, p - v1)) / length(v1 - v0),
 594                                   length(cross(p - v1, p     )) / length(v1)      };
 595                 float edge_dist = *std::min_element(edges, edges + 3);
 596
 597                 if (edge_dist < spacing) {
 598                   n -= 1.0;
 599                   continue;
 600                 }
 601
 602                 if (object_mask != NULL) {
 603                   SGVec2f texCoord = torigin + a*t0 + b*t1;
 604
 605                   // Check this random point against the object mask
 606                   // blue (for buildings) channel.
 607                   osg::Image* img = object_mask->getImage();
 608                   unsigned int x = (int) (img->s() * texCoord.x()) % img->s();
 609                   unsigned int y = (int) (img->t() * texCoord.y()) % img->t();
 610
 611                   if (mt_rand(&seed) > img->getColor(x, y).b()) {
 612                     // Failed object mask check
 613                     n -= 1.0;
 614                     continue;
 615                   }
 616
 617                   rotation = img->getColor(x,y).r();
 618                 }
 619
 620                 bool close = false;
 621
 622                 // Check it isn't too close to any other random objects in the triangle
 623                 std::vector<std::pair<SGVec3f, float> >::iterator l;
 624                 for (l = triangleObjectsList.begin(); l != triangleObjectsList.end(); ++l) {
 625                   float min_dist2 = (l->second + object->get_spacing_m()) *
 626                                     (l->second + object->get_spacing_m());
 627
 628                   if (distSqr(l->first, randomPoint) > min_dist2) {
 629                     close = true;
 630                     continue;
 631                   }
 632                 }
 633
 634                 if (!close) {
 635                     triangleObjectsList.push_back(std::make_pair(randomPoint, object->get_spacing_m()));
 636                     randomModels.insert(randomPoint,
 637                                         object,
 638                                         (int)object->get_randomized_range_m(&seed),
 639                                         rotation);
 640                 }
 641
 642                 n -= 1.0;
 643               }
 644             }
 645           }
 646         }
 647
 648         // Random objects now generated.  Now generate the random buildings (if any);
 649         if (use_random_buildings && (building_coverage > 0) && (building_density > 0)) {
 650
 651           // Calculate the number of buildings, taking into account building density (which is linear)
 652           // and the slope density factor.
 653           double num = building_density * building_density * slope_density * area / building_coverage;
 654
 655           // For partial units of area, use a zombie door method to
 656           // create the proper random chance of an object being created
 657           // for this triangle.
 658           num = num + mt_rand(&seed);
 659
 660           if (num < 1.0f) {
 661             continue;
 662           }
 663
 664           // Cosine of the angle between the two vectors.
 665           float cosine = (dot(v0, v1) / (length(v0) * length(v1)));
 666
 667           // Determine a grid spacing in each vector such that the correct
 668           // coverage will result.
 669           float stepv0 = (sqrtf(building_coverage) / building_density) / length(v0) / sqrtf(1 - cosine * cosine);
 670           float stepv1 = (sqrtf(building_coverage) / building_density) / length(v1);
 671
 672           stepv0 = std::min(stepv0, 1.0f);
 673           stepv1 = std::min(stepv1, 1.0f);
 674
 675           // Start at a random point. a will be immediately incremented below.
 676           float a = -mt_rand(&seed) * stepv0;
 677           float b = mt_rand(&seed) * stepv1;
 678
 679           // Place an object each unit of area
 680           while (num > 1.0) {
 681
 682             // Set the next location to place a building
 683             a += stepv0;
 684
 685             if ((a + b) > 1.0f) {
 686               // Reached the end of the scan-line on v0. Reset and increment
 687               // scan-line on v1
 688               a = mt_rand(&seed) * stepv0;
 689               b += stepv1;
 690             }
 691
 692             if (b > 1.0f) {
 693               // In a degenerate case of a single point, we might be outside the
 694               // scanline.  Note that we need to still ensure that a+b < 1.
 695               b = mt_rand(&seed) * stepv1 * (1.0f - a);
 696             }
 697
 698             if ((a + b) > 1.0f ) {
 699               // Truly degenerate case - simply choose a random point guaranteed
 700               // to fulfil the constraing of a+b < 1.
 701               a = mt_rand(&seed);
 702               b = mt_rand(&seed) * (1.0f - a);
 703             }
 704
 705             SGVec3f randomPoint = vorigin + a*v0 + b*v1;
 706             float rotation = mt_rand(&seed);
 707
 708             if (object_mask != NULL) {
 709               SGVec2f texCoord = torigin + a*t0 + b*t1;
 710               osg::Image* img = object_mask->getImage();
 711               int x = (int) (img->s() * texCoord.x()) % img->s();
 712               int y = (int) (img->t() * texCoord.y()) % img->t();
 713
 714               // In some degenerate cases x or y can be < 1, in which case the mod operand fails
 715               while (x < 0) x += img->s();
 716               while (y < 0) y += img->t();
 717
 718               if (mt_rand(&seed) < img->getColor(x, y).b()) {
 719                 // Object passes mask. Rotation is taken from the red channel
 720                 rotation = img->getColor(x,y).r();
 721               } else {
 722                 // Fails mask test - try again.
 723                 mask_dropped++;
 724                 num -= 1.0;
 725                 continue;
 726               }
 727             }
 728
 729             // Check building isn't too close to the triangle edge.
 730             float type_roll = mt_rand(&seed);
 731             SGBuildingBin::BuildingType buildingtype = bin->getBuildingType(type_roll);
 732             float radius = bin->getBuildingMaxRadius(buildingtype);
 733
 734             // Determine the actual center of the building, by shifting from the
 735             // center of the front face to the true center.
 736             osg::Matrix rotationMat = osg::Matrix::rotate(- rotation * M_PI * 2,
 737                                                  osg::Vec3f(0.0, 0.0, 1.0));
 738             SGVec3f buildingCenter = randomPoint + toSG(osg::Vec3f(-0.5 * bin->getBuildingMaxDepth(buildingtype), 0.0, 0.0) * rotationMat);
 739
 740             SGVec3f p = buildingCenter - vorigin;
 741             float edges[] = { length(cross(p     , p - v0)) / length(v0),
 742                               length(cross(p - v0, p - v1)) / length(v1 - v0),
 743                               length(cross(p - v1, p     )) / length(v1)      };
 744             float edge_dist = *std::min_element(edges, edges + 3);
 745
 746             if (edge_dist < radius) {
 747               num -= 1.0;
 748               triangle_dropped++;
 749               continue;
 750             }
 751
 752             // Check building isn't too close to random objects and other buildings.
 753             bool close = false;
 754             std::vector<std::pair<SGVec3f, float> >::iterator iter;
 755
 756             for (iter = triangleBuildingList.begin(); iter != triangleBuildingList.end(); ++iter) {
 757               float min_dist = iter->second + radius;
 758               if (distSqr(iter->first, buildingCenter) < min_dist * min_dist) {
 759                 close = true;
 760                 continue;
 761               }
 762             }
 763
 764             if (close) {
 765               num -= 1.0;
 766               building_dropped++;
 767               continue;
 768             }
 769
 770             for (iter = triangleObjectsList.begin(); iter != triangleObjectsList.end(); ++iter) {
 771               float min_dist = iter->second + radius;
 772               if (distSqr(iter->first, buildingCenter) < min_dist * min_dist) {
 773                 close = true;
 774                 continue;
 775               }
 776             }
 777
 778             if (close) {
 779               num -= 1.0;
 780               random_dropped++;
 781               continue;
 782             }
 783
 784             std::pair<SGVec3f, float> pt = std::make_pair(buildingCenter, radius);
 785             triangleBuildingList.push_back(pt);
 786             bin->insert(randomPoint, rotation, buildingtype);
 787             num -= 1.0;
 788           }
 789         }
 790
 791         triangleObjectsList.clear();
 792         triangleBuildingList.clear();
 793       }
 794
 795       SG_LOG(SG_TERRAIN, SG_DEBUG, "Random Buildings: " << ((bin) ? bin->getNumBuildings() : 0));
 796       SG_LOG(SG_TERRAIN, SG_DEBUG, "  Dropped due to mask: " << mask_dropped);
 797       SG_LOG(SG_TERRAIN, SG_DEBUG, "  Dropped due to random object: " << random_dropped);
 798       SG_LOG(SG_TERRAIN, SG_DEBUG, "  Dropped due to other buildings: " << building_dropped);
 799     }
 800   }
 801
 802   void computeRandomForest(SGMaterialLib* matlib, float vegetation_density)
 803   {
 804     SGMaterialTriangleMap::iterator i;
 805
 806     // generate a repeatable random seed
 807     mt seed;
 808
 809     mt_init(&seed, unsigned(586));
 810
 811     for (i = materialTriangleMap.begin(); i != materialTriangleMap.end(); ++i) {
 812       SGMaterial *mat = matlib->find(i->first);
 813       if (!mat)
 814         continue;
 815
 816       float wood_coverage = mat->get_wood_coverage();
 817       if ((wood_coverage <= 0) || (vegetation_density <= 0))
 818         continue;
 819
 820       // Attributes that don't vary by tree but do vary by material
 821       bool found = false;
 822       TreeBin* bin = NULL;
 823
 824       BOOST_FOREACH(bin, randomForest)
 825       {
 826         if ((bin->texture           == mat->get_tree_texture()  ) &&
 827             (bin->texture_varieties == mat->get_tree_varieties()) &&
 828             (bin->range             == mat->get_tree_range()    ) &&
 829             (bin->width             == mat->get_tree_width()    ) &&
 830             (bin->height            == mat->get_tree_height()   )   ) {
 831             found = true;
 832             break;
 833         }
 834       }
 835
 836       if (!found) {
 837         bin = new TreeBin();
 838         bin->texture = mat->get_tree_texture();
 839           SG_LOG(SG_INPUT, SG_DEBUG, "Tree texture " << bin->texture);
 840         bin->range   = mat->get_tree_range();
 841         bin->width   = mat->get_tree_width();
 842         bin->height  = mat->get_tree_height();
 843         bin->texture_varieties = mat->get_tree_varieties();
 844         randomForest.push_back(bin);
 845       }
 846
 847       std::vector<SGVec3f> randomPoints;
 848       i->second.addRandomTreePoints(wood_coverage,
 849                                     mat->get_object_mask(i->second),
 850                                     vegetation_density,
 851                                     mat->get_cos_tree_max_density_slope_angle(),
 852                                     mat->get_cos_tree_zero_density_slope_angle(),
 853                                     randomPoints);
 854
 855       std::vector<SGVec3f>::iterator k;
 856       for (k = randomPoints.begin(); k != randomPoints.end(); ++k) {
 857         bin->insert(*k);
 858       }
 859     }
 860   }
 861
 862   bool insertBinObj(const SGBinObject& obj, SGMaterialLib* matlib)
 863   {
 864     if (!insertPtGeometry(obj, matlib))
 865       return false;
 866     if (!insertSurfaceGeometry(obj, matlib))
 867       return false;
 868     return true;
 869   }
 870 };
 871
 872 typedef std::pair<osg::Node*, int> ModelLOD;
 873 struct MakeQuadLeaf {
 874     osg::LOD* operator() () const { return new osg::LOD; }
 875 };
 876 struct AddModelLOD {
 877     void operator() (osg::LOD* leaf, ModelLOD& mlod) const
 878     {
 879         leaf->addChild(mlod.first, 0, mlod.second);
 880     }
 881 };
 882 struct GetModelLODCoord {
 883     GetModelLODCoord() {}
 884     GetModelLODCoord(const GetModelLODCoord& rhs)
 885     {}
 886     osg::Vec3 operator() (const ModelLOD& mlod) const
 887     {
 888         return mlod.first->getBound().center();
 889     }
 890 };
 891
 892 typedef QuadTreeBuilder<osg::LOD*, ModelLOD, MakeQuadLeaf, AddModelLOD,
 893                         GetModelLODCoord>  RandomObjectsQuadtree;
 894
 895 osg::Node*
 896 SGLoadBTG(const std::string& path, const simgear::SGReaderWriterOptions* options)
 897 {
 898   SGBinObject tile;
 899   if (!tile.read_bin(path))
 900     return NULL;
 901
 902   SGMaterialLib* matlib = 0;
 903   bool use_random_objects = false;
 904   bool use_random_vegetation = false;
 905   bool use_random_buildings = false;
 906   float vegetation_density = 1.0f;
 907   float building_density = 1.0f;
 908   if (options) {
 909     matlib = options->getMaterialLib();
 910     SGPropertyNode* propertyNode = options->getPropertyNode().get();
 911     if (propertyNode) {
 912         use_random_objects
 913             = propertyNode->getBoolValue("/sim/rendering/random-objects",
 914                                          use_random_objects);
 915         use_random_vegetation
 916             = propertyNode->getBoolValue("/sim/rendering/random-vegetation",
 917                                          use_random_vegetation);
 918         vegetation_density
 919             = propertyNode->getFloatValue("/sim/rendering/vegetation-density",
 920                                           vegetation_density);
 921         use_random_buildings
 922             = propertyNode->getBoolValue("/sim/rendering/random-buildings",
 923                                          use_random_buildings);
 924         building_density
 925             = propertyNode->getFloatValue("/sim/rendering/building-density",
 926                                           building_density);
 927     }
 928   }
 929
 930   SGVec3d center = tile.get_gbs_center();
 931   SGGeod geodPos = SGGeod::fromCart(center);
 932   SGQuatd hlOr = SGQuatd::fromLonLat(geodPos)*SGQuatd::fromEulerDeg(0, 0, 180);
 933
 934   // rotate the tiles so that the bounding boxes get nearly axis aligned.
 935   // this will help the collision tree's bounding boxes a bit ...
 936   std::vector<SGVec3d> nodes = tile.get_wgs84_nodes();
 937   for (unsigned i = 0; i < nodes.size(); ++i)
 938     nodes[i] = hlOr.transform(nodes[i]);
 939   tile.set_wgs84_nodes(nodes);
 940
 941   SGQuatf hlOrf(hlOr[0], hlOr[1], hlOr[2], hlOr[3]);
 942   std::vector<SGVec3f> normals = tile.get_normals();
 943   for (unsigned i = 0; i < normals.size(); ++i)
 944     normals[i] = hlOrf.transform(normals[i]);
 945   tile.set_normals(normals);
 946
 947   SGTileGeometryBin tileGeometryBin;
 948   if (!tileGeometryBin.insertBinObj(tile, matlib))
 949     return NULL;
 950
 951   SGVec3f up(0, 0, 1);
 952   GroundLightManager* lightManager = GroundLightManager::instance();
 953
 954   osg::ref_ptr<osg::Group> lightGroup = new SGOffsetTransform(0.94);
 955   osg::ref_ptr<osg::Group> randomObjects;
 956   osg::ref_ptr<osg::Group> forestNode;
 957   osg::ref_ptr<osg::Group> buildingNode;
 958   osg::Group* terrainGroup = new osg::Group;
 959   terrainGroup->setName("BTGTerrainGroup");
 960
 961   osg::Node* node = tileGeometryBin.getSurfaceGeometry(matlib);
 962   if (node)
 963     terrainGroup->addChild(node);
 964
 965   if (matlib && (use_random_objects || use_random_buildings)) {
 966     tileGeometryBin.computeRandomObjectsAndBuildings(matlib,
 967                                                      building_density,
 968                                                      use_random_objects,
 969                                                      use_random_buildings);
 970   }
 971
 972   if (tileGeometryBin.randomModels.getNumModels() > 0) {
 973     // Generate a repeatable random seed
 974     mt seed;
 975     mt_init(&seed, unsigned(123));
 976
 977     std::vector<ModelLOD> models;
 978     for (unsigned int i = 0;
 979          i < tileGeometryBin.randomModels.getNumModels(); i++) {
 980       SGMatModelBin::MatModel obj
 981         = tileGeometryBin.randomModels.getMatModel(i);
 982
 983       SGPropertyNode* root = options->getPropertyNode()->getRootNode();
 984       osg::Node* node = obj.model->get_random_model(root, &seed);
 985
 986       // Create a matrix to place the object in the correct
 987       // location, and then apply the rotation matrix created
 988       // above, with an additional random (or taken from
 989       // the object mask) heading rotation if appropriate.
 990       osg::Matrix transformMat;
 991       transformMat = osg::Matrix::translate(toOsg(obj.position));
 992       if (obj.model->get_heading_type() == SGMatModel::HEADING_RANDOM) {
 993         // Rotate the object around the z axis.
 994         double hdg = mt_rand(&seed) * M_PI * 2;
 995         transformMat.preMult(osg::Matrix::rotate(hdg,
 996                                                  osg::Vec3d(0.0, 0.0, 1.0)));
 997       }
 998
 999       if (obj.model->get_heading_type() == SGMatModel::HEADING_MASK) {
1000         // Rotate the object around the z axis.
1001         double hdg =  - obj.rotation * M_PI * 2;
1002         transformMat.preMult(osg::Matrix::rotate(hdg,
1003                                                  osg::Vec3d(0.0, 0.0, 1.0)));
1004       }
1005
1006       osg::MatrixTransform* position =
1007         new osg::MatrixTransform(transformMat);
1008       position->setName("positionRandomeModel");
1009       position->addChild(node);
1010       models.push_back(ModelLOD(position, obj.lod));
1011     }
1012     RandomObjectsQuadtree quadtree((GetModelLODCoord()), (AddModelLOD()));
1013     quadtree.buildQuadTree(models.begin(), models.end());
1014     randomObjects = quadtree.getRoot();
1015     randomObjects->setName("Random objects");
1016   }
1017
1018   if (! tileGeometryBin.randomBuildings.empty()) {
1019     buildingNode = createRandomBuildings(tileGeometryBin.randomBuildings, osg::Matrix::identity(),
1020                                 options);
1021     buildingNode->setName("Random buildings");
1022   }
1023
1024   if (use_random_vegetation && matlib) {
1025     // Now add some random forest.
1026     tileGeometryBin.computeRandomForest(matlib, vegetation_density);
1027
1028     if (! tileGeometryBin.randomForest.empty()) {
1029       forestNode = createForest(tileGeometryBin.randomForest, osg::Matrix::identity(),
1030                                 options);
1031       forestNode->setName("Random trees");
1032     }
1033   }
1034
1035   // FIXME: ugly, has a side effect
1036   if (matlib)
1037     tileGeometryBin.computeRandomSurfaceLights(matlib);
1038
1039   if (tileGeometryBin.tileLights.getNumLights() > 0
1040       || tileGeometryBin.randomTileLights.getNumLights() > 0) {
1041     osg::Group* groundLights0 = new osg::Group;
1042     groundLights0->setStateSet(lightManager->getGroundLightStateSet());
1043     groundLights0->setNodeMask(GROUNDLIGHTS0_BIT);
1044     osg::Geode* geode = new osg::Geode;
1045     geode->addDrawable(SGLightFactory::getLights(tileGeometryBin.tileLights));
1046     geode->addDrawable(SGLightFactory::getLights(tileGeometryBin.randomTileLights, 4, -0.3f));
1047     groundLights0->addChild(geode);
1048     lightGroup->addChild(groundLights0);
1049   }
1050
1051   if (tileGeometryBin.randomTileLights.getNumLights() > 0) {
1052     osg::Group* groundLights1 = new osg::Group;
1053     groundLights1->setStateSet(lightManager->getGroundLightStateSet());
1054     groundLights1->setNodeMask(GROUNDLIGHTS1_BIT);
1055     osg::Group* groundLights2 = new osg::Group;
1056     groundLights2->setStateSet(lightManager->getGroundLightStateSet());
1057     groundLights2->setNodeMask(GROUNDLIGHTS2_BIT);
1058     osg::Geode* geode = new osg::Geode;
1059     geode->addDrawable(SGLightFactory::getLights(tileGeometryBin.randomTileLights, 2, -0.15f));
1060     groundLights1->addChild(geode);
1061     lightGroup->addChild(groundLights1);
1062     geode = new osg::Geode;
1063     geode->addDrawable(SGLightFactory::getLights(tileGeometryBin.randomTileLights));
1064     groundLights2->addChild(geode);
1065     lightGroup->addChild(groundLights2);
1066   }
1067
1068   if (!tileGeometryBin.vasiLights.empty()) {
1069     EffectGeode* vasiGeode = new EffectGeode;
1070     Effect* vasiEffect
1071         = getLightEffect(24, osg::Vec3(1, 0.0001, 0.000001), 1, 24, true);
1072     vasiGeode->setEffect(vasiEffect);
1073     SGVec4f red(1, 0, 0, 1);
1074     SGMaterial* mat = 0;
1075     if (matlib)
1076       mat = matlib->find("RWY_RED_LIGHTS");
1077     if (mat)
1078       red = mat->get_light_color();
1079     SGVec4f white(1, 1, 1, 1);
1080     mat = 0;
1081     if (matlib)
1082       mat = matlib->find("RWY_WHITE_LIGHTS");
1083     if (mat)
1084       white = mat->get_light_color();
1085     SGDirectionalLightListBin::const_iterator i;
1086     for (i = tileGeometryBin.vasiLights.begin();
1087          i != tileGeometryBin.vasiLights.end(); ++i) {
1088       vasiGeode->addDrawable(SGLightFactory::getVasi(up, *i, red, white));
1089     }
1090     vasiGeode->setStateSet(lightManager->getRunwayLightStateSet());
1091     lightGroup->addChild(vasiGeode);
1092   }
1093
1094   Effect* runwayEffect = 0;
1095   if (tileGeometryBin.runwayLights.getNumLights() > 0
1096       || !tileGeometryBin.rabitLights.empty()
1097       || !tileGeometryBin.reilLights.empty()
1098       || !tileGeometryBin.odalLights.empty()
1099       || tileGeometryBin.taxiLights.getNumLights() > 0)
1100       runwayEffect = getLightEffect(16, osg::Vec3(1, 0.001, 0.0002), 1, 16, true);
1101   if (tileGeometryBin.runwayLights.getNumLights() > 0
1102       || !tileGeometryBin.rabitLights.empty()
1103       || !tileGeometryBin.reilLights.empty()
1104       || !tileGeometryBin.odalLights.empty()
1105       || !tileGeometryBin.holdshortLights.empty()
1106       || !tileGeometryBin.guardLights.empty()) {
1107     osg::Group* rwyLights = new osg::Group;
1108     rwyLights->setStateSet(lightManager->getRunwayLightStateSet());
1109     rwyLights->setNodeMask(RUNWAYLIGHTS_BIT);
1110     if (tileGeometryBin.runwayLights.getNumLights() != 0) {
1111       EffectGeode* geode = new EffectGeode;
1112       geode->setEffect(runwayEffect);
1113       geode->addDrawable(SGLightFactory::getLights(tileGeometryBin
1114                                                    .runwayLights));
1115       rwyLights->addChild(geode);
1116     }
1117     SGDirectionalLightListBin::const_iterator i;
1118     for (i = tileGeometryBin.rabitLights.begin();
1119          i != tileGeometryBin.rabitLights.end(); ++i) {
1120       rwyLights->addChild(SGLightFactory::getSequenced(*i));
1121     }
1122     for (i = tileGeometryBin.reilLights.begin();
1123          i != tileGeometryBin.reilLights.end(); ++i) {
1124       rwyLights->addChild(SGLightFactory::getSequenced(*i));
1125     }
1126     for (i = tileGeometryBin.holdshortLights.begin();
1127          i != tileGeometryBin.holdshortLights.end(); ++i) {
1128       rwyLights->addChild(SGLightFactory::getHoldShort(*i));
1129     }
1130     for (i = tileGeometryBin.guardLights.begin();
1131          i != tileGeometryBin.guardLights.end(); ++i) {
1132       rwyLights->addChild(SGLightFactory::getGuard(*i));
1133     }
1134     SGLightListBin::const_iterator j;
1135     for (j = tileGeometryBin.odalLights.begin();
1136          j != tileGeometryBin.odalLights.end(); ++j) {
1137       rwyLights->addChild(SGLightFactory::getOdal(*j));
1138     }
1139     lightGroup->addChild(rwyLights);
1140   }
1141
1142   if (tileGeometryBin.taxiLights.getNumLights() > 0) {
1143     osg::Group* taxiLights = new osg::Group;
1144     taxiLights->setStateSet(lightManager->getTaxiLightStateSet());
1145     taxiLights->setNodeMask(RUNWAYLIGHTS_BIT);
1146     EffectGeode* geode = new EffectGeode;
1147     geode->setEffect(runwayEffect);
1148     geode->addDrawable(SGLightFactory::getLights(tileGeometryBin.taxiLights));
1149     taxiLights->addChild(geode);
1150     lightGroup->addChild(taxiLights);
1151   }
1152
1153   // The toplevel transform for that tile.
1154   osg::MatrixTransform* transform = new osg::MatrixTransform;
1155   transform->setName(path);
1156   transform->setMatrix(osg::Matrix::rotate(toOsg(hlOr))*
1157                        osg::Matrix::translate(toOsg(center)));
1158   transform->addChild(terrainGroup);
1159   if (lightGroup->getNumChildren() > 0) {
1160     osg::LOD* lightLOD = new osg::LOD;
1161     lightLOD->addChild(lightGroup.get(), 0, 60000);
1162     // VASI is always on, so doesn't use light bits.
1163     lightLOD->setNodeMask(LIGHTS_BITS | MODEL_BIT | PERMANENTLIGHT_BIT);
1164     transform->addChild(lightLOD);
1165   }
1166
1167   if (randomObjects.valid() || forestNode.valid() || buildingNode.valid()) {
1168
1169     // Add a LoD node, so we don't try to display anything when the tile center
1170     // is more than 20km away.
1171     osg::LOD* objectLOD = new osg::LOD;
1172
1173     if (randomObjects.valid()) objectLOD->addChild(randomObjects.get(), 0, 20000);
1174     if (forestNode.valid())  objectLOD->addChild(forestNode.get(), 0, 20000);
1175     if (buildingNode.valid()) objectLOD->addChild(buildingNode.get(), 0, 20000);
1176
1177     unsigned nodeMask = SG_NODEMASK_CASTSHADOW_BIT | SG_NODEMASK_RECEIVESHADOW_BIT | SG_NODEMASK_TERRAIN_BIT;
1178     objectLOD->setNodeMask(nodeMask);
1179     transform->addChild(objectLOD);
1180   }
1181   transform->setNodeMask( ~simgear::MODELLIGHT_BIT );
1182
1183   return transform;
1184 }