src/Environment/fgclouds.cxx

   1 // Build a cloud layer based on metar
   2 //
   3 // Written by Harald JOHNSEN, started April 2005.
   4 //
   5 // Copyright (C) 2005  Harald JOHNSEN - hjohnsen@evc.net
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 //
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include "config.h"
  25 #endif
  26
  27 #include <Main/fg_props.hxx>
  28
  29 #include <simgear/constants.h>
  30 #include <simgear/sound/soundmgr_openal.hxx>
  31 #include <simgear/scene/sky/sky.hxx>
  32 #include <simgear/environment/visual_enviro.hxx>
  33 #include <simgear/scene/sky/cloudfield.hxx>
  34 #include <simgear/scene/sky/newcloud.hxx>
  35 #include <simgear/math/sg_random.h>
  36 #include <simgear/props/props_io.hxx>
  37
  38 #include <Main/globals.hxx>
  39 #include <Airports/simple.hxx>
  40 #include <Main/util.hxx>
  41
  42 #include "environment_ctrl.hxx"
  43 #include "environment_mgr.hxx"
  44 #include "fgmetar.hxx"
  45 #include "fgclouds.hxx"
  46
  47 extern SGSky *thesky;
  48
  49
  50 FGClouds::FGClouds(FGEnvironmentCtrl * controller) :
  51         station_elevation_ft(0.0),
  52         _controller( controller ),
  53         snd_lightning(NULL),
  54     last_scenario( "unset" ),
  55     last_env_config( new SGPropertyNode() ),
  56     last_env_clouds( new SGPropertyNode() )
  57 {
  58         update_event = 0;
  59 }
  60 FGClouds::~FGClouds() {
  61 }
  62
  63 int FGClouds::get_update_event(void) const {
  64         return update_event;
  65 }
  66 void FGClouds::set_update_event(int count) {
  67         update_event = count;
  68         buildCloudLayers();
  69 }
  70
  71 void FGClouds::init(void) {
  72         if( snd_lightning == NULL ) {
  73                 snd_lightning = new SGSoundSample(globals->get_fg_root().c_str(), "Sounds/thunder.wav");
  74                 snd_lightning->set_max_dist(7000.0f);
  75                 snd_lightning->set_reference_dist(3000.0f);
  76                 SGSoundMgr *soundMgr = globals->get_soundmgr();
  77                 soundMgr->add( snd_lightning, "thunder" );
  78                 sgEnviro.set_soundMgr( soundMgr );
  79         }
  80 }
  81
  82 void FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode  *box_def_root, const string& name, sgVec3 pos, SGCloudField *layer) {
  83         SGPropertyNode *box_def=NULL;
  84         SGPropertyNode *cld_def=NULL;
  85
  86         SGPath texture_root = globals->get_fg_root();
  87         texture_root.append("Textures");
  88         texture_root.append("Sky");
  89
  90         box_def = box_def_root->getChild(name.c_str());
  91
  92         string base_name = name.substr(0,2);
  93         if( !box_def ) {
  94                 if( name[2] == '-' ) {
  95                         box_def = box_def_root->getChild(base_name.c_str());
  96                 }
  97                 if( !box_def )
  98                         return;
  99         }
 100
 101         for(int i = 0; i < box_def->nChildren() ; i++) {
 102                 SGPropertyNode *abox = box_def->getChild(i);
 103                 if( strcmp(abox->getName(), "box") == 0) {
 104                         double x = abox->getDoubleValue("x") + pos[0];
 105                         double y = abox->getDoubleValue("y") + pos[1];
 106                         double z = abox->getDoubleValue("z") + pos[2];
 107                         SGVec3f newpos = SGVec3f(x, z, y);
 108
 109                         string type = abox->getStringValue("type", "cu-small");
 110
 111                         cld_def = cloud_def_root->getChild(type.c_str());
 112                         if ( !cld_def ) return;
 113
 114                         double min_width = cld_def->getDoubleValue("min-cloud-width-m", 500.0);
 115                         double max_width = cld_def->getDoubleValue("max-cloud-width-m", 1000.0);
 116                         double min_height = cld_def->getDoubleValue("min-cloud-height-m", min_width);
 117                         double max_height = cld_def->getDoubleValue("max-cloud-height-m", max_width);
 118                         double min_sprite_width = cld_def->getDoubleValue("min-sprite-width-m", 200.0);
 119                         double max_sprite_width = cld_def->getDoubleValue("max-sprite-width-m", min_sprite_width);
 120                         double min_sprite_height = cld_def->getDoubleValue("min-sprite-height-m", min_sprite_width);
 121                         double max_sprite_height = cld_def->getDoubleValue("max-sprite-height-m", max_sprite_width);
 122                         int num_sprites = cld_def->getIntValue("num-sprites", 20);
 123                         int num_textures_x = cld_def->getIntValue("num-textures-x", 1);
 124                         int num_textures_y = cld_def->getIntValue("num-textures-y", 1);
 125                         double bottom_shade = cld_def->getDoubleValue("bottom-shade", 1.0);
 126                         string texture = cld_def->getStringValue("texture", "cl_cumulus.rgb");
 127
 128                         SGNewCloud *cld =
 129                                 new SGNewCloud(type,
 130                                                texture_root,
 131                                                texture,
 132                                                min_width,
 133                                                max_width,
 134                                                min_height,
 135                                                max_height,
 136                                                min_sprite_width,
 137                                                max_sprite_width,
 138                                                min_sprite_height,
 139                                                max_sprite_height,
 140                                                bottom_shade,
 141                                                num_sprites,
 142                                                num_textures_x,
 143                                                num_textures_y);
 144                         layer->addCloud(newpos, cld);
 145                 }
 146         }
 147 }
 148
 149 void FGClouds::buildLayer(int iLayer, const string& name, double alt, double coverage) {
 150         struct {
 151                 string name;
 152                 double count;
 153         } tCloudVariety[20];
 154         int CloudVarietyCount = 0;
 155         double totalCount = 0.0;
 156
 157         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 158         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 159         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 160         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 161         layer->clear();
 162
 163         // If we don't have the required properties, then render the cloud in 2D
 164         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 165             layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL)
 166         {
 167                 thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 168                 return;
 169         }
 170
 171         // If we can't find a definition for this cloud type, then render the cloud in 2D
 172         SGPropertyNode *layer_def=NULL;
 173         layer_def = layer_def_root->getChild(name.c_str());
 174         if( !layer_def ) {
 175                 if( name[2] == '-' ) {
 176                         string base_name = name.substr(0,2);
 177                         layer_def = layer_def_root->getChild(base_name.c_str());
 178                 }
 179                 if( !layer_def )
 180                 {
 181                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 182                         return;
 183                 }
 184         }
 185
 186         // At this point, we know we've got some 3D clouds to generate.
 187         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 188
 189         double grid_x_size = layer_def->getDoubleValue("grid-x-size", 1000.0);
 190         double grid_y_size = layer_def->getDoubleValue("grid-y-size", 1000.0);
 191         double grid_x_rand = layer_def->getDoubleValue("grid-x-rand", grid_x_size);
 192         double grid_y_rand = layer_def->getDoubleValue("grid-y-rand", grid_y_size);
 193         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 194
 195         for(int i = 0; i < layer_def->nChildren() ; i++) {
 196                 SGPropertyNode *acloud = layer_def->getChild(i);
 197                 if( strcmp(acloud->getName(), "cloud") == 0) {
 198                         string cloud_name = acloud->getStringValue("name");
 199                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 200                         double count = acloud->getDoubleValue("count", 1.0);
 201                         tCloudVariety[CloudVarietyCount].count = count;
 202                         int variety = 0;
 203                         cloud_name = cloud_name + "-%d";
 204                         char variety_name[50];
 205                         do {
 206                                 variety++;
 207                                 snprintf(variety_name, sizeof(variety_name), cloud_name.c_str(), variety);
 208                         } while( box_def_root->getChild(variety_name, 0, false) );
 209
 210                         totalCount += count;
 211                         if( CloudVarietyCount < 20 )
 212                                 CloudVarietyCount++;
 213                 }
 214         }
 215         totalCount = 1.0 / totalCount;
 216
 217         for(double px = 0.0; px < SGCloudField::fieldSize; px += grid_x_size) {
 218                 for(double py = 0.0; py < SGCloudField::fieldSize; py += grid_y_size) {
 219                         double x = px + grid_x_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 220                         double y = py + grid_y_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 221                         double z = grid_z_rand * (sg_random() - 0.5);
 222
 223                         if (sg_random() < coverage)
 224                         {
 225                             double choice = sg_random();
 226
 227                             for(int i = 0; i < CloudVarietyCount ; i ++) {
 228                                     choice -= tCloudVariety[i].count * totalCount;
 229                                     if( choice <= 0.0 ) {
 230                                             sgVec3 pos={x,z,y};
 231
 232                                             buildCloud(cloud_def_root,
 233                                                        box_def_root,
 234                                                        tCloudVariety[i].name,
 235                                                        pos,
 236                                                        layer);
 237                                             break;
 238                                     }
 239                             }
 240                         }
 241                 }
 242         }
 243
 244         // Now we've built any clouds, enable them and set the density (coverage)
 245         //layer->setCoverage(coverage);
 246         //layer->applyCoverage();
 247         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 248 }
 249
 250 void FGClouds::buildCloudLayers(void) {
 251         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 252
 253         double wind_speed_kt     = metar_root->getDoubleValue("wind-speed-kt");
 254         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 255         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 256         double pressure_mb              = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 257
 258         double dewp = pow(10.0, 7.5 * dewpoint_degc / (237.7 + dewpoint_degc));
 259         double temp = pow(10.0, 7.5 * temperature_degc / (237.7 + temperature_degc));
 260         double rel_humidity = dewp * 100 / temp;
 261
 262         // formule d'Epsy, base d'un cumulus
 263         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 264         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 265
 266         bool cu_seen = false;
 267
 268         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 269                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 270
 271                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 272                 double alt_m = alt_ft * SG_FEET_TO_METER;
 273                 string coverage = cloud_root->getStringValue("coverage");
 274
 275
 276                 double coverage_norm = 0.0;
 277                 if( coverage == "few" )
 278                         coverage_norm = 2.0/8.0;        // <1-2
 279                 else if( coverage == "scattered" )
 280                         coverage_norm = 4.0/8.0;        // 3-4
 281                 else if( coverage == "broken" )
 282                         coverage_norm = 6.0/8.0;        // 5-7
 283                 else if( coverage == "overcast" )
 284                         coverage_norm = 8.0/8.0;        // 8
 285
 286                 string layer_type = "nn";
 287                 if( coverage == "cirrus" ) {
 288                         layer_type = "ci";
 289                 } else if( alt_ft > 16500 ) {
 290 //                      layer_type = "ci|cs|cc";
 291                         layer_type = "ci";
 292                 } else if( alt_ft > 6500 ) {
 293 //                      layer_type = "as|ac|ns";
 294                         layer_type = "ac";
 295                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 296                                 layer_type = "ns";
 297                 } else {
 298 //                      layer_type = "st|cu|cb|sc";
 299                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 300                                 // +/- 20% from cumulus probable base
 301                                 layer_type = "cu";
 302                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 303                                 // +/- 20% from stratus probable base
 304                                 layer_type = "st";
 305                         } else {
 306                                 // above formulae is far from perfect
 307                                 if ( alt_ft < 2000 )
 308                                         layer_type = "st";
 309                                 else if( alt_ft < 4500 )
 310                                         layer_type = "cu";
 311                                 else
 312                                         layer_type = "sc";
 313                         }
 314                 }
 315
 316                 buildLayer(iLayer, layer_type, alt_m, coverage_norm);
 317         }
 318 }
 319
 320 // copy from FGMetarEnvironmentCtrl until better
 321 void
 322 FGClouds::update_metar_properties( const FGMetar *m )
 323 {
 324     int i;
 325     int j;
 326     double d;
 327     char s[128];
 328
 329     fgSetString("/environment/metar/station-id", m->getId());
 330     fgSetDouble("/environment/metar/min-visibility-m",
 331                 m->getMinVisibility().getVisibility_m() );
 332     fgSetDouble("/environment/metar/max-visibility-m",
 333                 m->getMaxVisibility().getVisibility_m() );
 334
 335     const SGMetarVisibility *dirvis = m->getDirVisibility();
 336     for (i = 0; i < 8; i++, dirvis++) {
 337         const char *min = "/environment/metar/visibility[%d]/min-m";
 338         const char *max = "/environment/metar/visibility[%d]/max-m";
 339
 340         d = dirvis->getVisibility_m();
 341
 342         snprintf(s, 128, min, i);
 343         fgSetDouble(s, d);
 344         snprintf(s, 128, max, i);
 345         fgSetDouble(s, d);
 346     }
 347
 348     fgSetInt("/environment/metar/base-wind-range-from",
 349              m->getWindRangeFrom() );
 350     fgSetInt("/environment/metar/base-wind-range-to",
 351              m->getWindRangeTo() );
 352     fgSetDouble("/environment/metar/base-wind-speed-kt",
 353                 m->getWindSpeed_kt() );
 354     fgSetDouble("/environment/metar/gust-wind-speed-kt",
 355                 m->getGustSpeed_kt() );
 356     fgSetDouble("/environment/metar/temperature-degc",
 357                 m->getTemperature_C() );
 358     fgSetDouble("/environment/metar/dewpoint-degc",
 359                 m->getDewpoint_C() );
 360     fgSetDouble("/environment/metar/rel-humidity-norm",
 361                 m->getRelHumidity() );
 362     fgSetDouble("/environment/metar/pressure-inhg",
 363                 m->getPressure_inHg() );
 364
 365     vector<SGMetarCloud> cv = m->getClouds();
 366     vector<SGMetarCloud>::const_iterator cloud;
 367
 368     // Load into both the METAR and environment properties to stop interpolation
 369     const char *cl[] = {"/environment/metar/clouds/layer[%i]",
 370                         "/environment/clouds/layer[%i]"};
 371
 372     for (j = 0; j < 2; j++)
 373     {
 374         for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
 375             const char *coverage_string[5] =
 376                 { "clear", "few", "scattered", "broken", "overcast" };
 377             const double thickness[5] = { 0, 65, 600,750, 1000};
 378             int q;
 379
 380             snprintf(s, 128, cl[j], i);
 381             strncat(s, "/coverage", 128);
 382             q = cloud->getCoverage();
 383             fgSetString(s, coverage_string[q] );
 384
 385             snprintf(s, 128, cl[j], i);
 386             strncat(s, "/elevation-ft", 128);
 387             fgSetDouble(s, cloud->getAltitude_ft() + station_elevation_ft);
 388
 389             snprintf(s, 128, cl[j], i);
 390             strncat(s, "/thickness-ft", 128);
 391             fgSetDouble(s, thickness[q]);
 392
 393             snprintf(s, 128, cl[j], i);
 394             strncat(s, "/span-m", 128);
 395             fgSetDouble(s, 40000.0);
 396         }
 397
 398         for (; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 399
 400
 401             snprintf(s, 128, cl[j], i);
 402             strncat(s, "/coverage", 128);
 403             fgSetString(s, "clear");
 404
 405             snprintf(s, 128, cl[j], i);
 406             strncat(s, "/elevation-ft", 128);
 407             fgSetDouble(s, -9999);
 408
 409             snprintf(s, 128, cl[j], i);
 410             strncat(s, "/thickness-ft", 128);
 411             fgSetDouble(s, 0);
 412
 413             snprintf(s, 128, cl[j], i);
 414             strncat(s, "/span-m", 128);
 415             fgSetDouble(s, 40000.0);
 416         }
 417     }
 418
 419     fgSetDouble("/environment/metar/rain-norm", m->getRain());
 420     fgSetDouble("/environment/metar/hail-norm", m->getHail());
 421     fgSetDouble("/environment/metar/snow-norm", m->getSnow());
 422     fgSetBool("/environment/metar/snow-cover", m->getSnowCover());
 423 }
 424
 425 void
 426 FGClouds::update_env_config ()
 427 {
 428     fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
 429                  fgGetDouble("/environment/metar/base-wind-range-to"),
 430                  fgGetDouble("/environment/metar/base-wind-speed-kt"),
 431                  fgGetDouble("/environment/metar/gust-wind-speed-kt") );
 432
 433     fgDefaultWeatherValue( "visibility-m",
 434                            fgGetDouble("/environment/metar/min-visibility-m") );
 435 #if 0
 436     set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
 437                           station_elevation_ft );
 438     set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
 439                               station_elevation_ft );
 440 #endif
 441     fgDefaultWeatherValue( "pressure-sea-level-inhg",
 442                            fgGetDouble("/environment/metar/pressure-inhg") );
 443 }
 444
 445 void FGClouds::setLayer( int iLayer, float alt_ft, const string& coverage, const string& layer_type ) {
 446         double coverage_norm = 0.0;
 447         if( coverage == "few" )
 448                 coverage_norm = 2.0/8.0;        // <1-2
 449         else if( coverage == "scattered" )
 450                 coverage_norm = 4.0/8.0;        // 3-4
 451         else if( coverage == "broken" )
 452                 coverage_norm = 6.0/8.0;        // 5-7
 453         else if( coverage == "overcast" )
 454                 coverage_norm = 8.0/8.0;        // 8
 455
 456         buildLayer(iLayer, layer_type, station_elevation_ft + alt_ft * SG_FEET_TO_METER, coverage_norm);
 457 }
 458
 459 void FGClouds::buildScenario( const string& scenario ) {
 460         string fakeMetar="";
 461         string station = fgGetString("/environment/metar/station-id", "XXXX");
 462
 463         // fetch station elevation if exists
 464         if( station == "XXXX" )
 465             station_elevation_ft = fgGetDouble("/position/ground-elev-m", 0.0);
 466         else {
 467             const FGAirport* a = FGAirport::findByIdent(station);
 468             station_elevation_ft = (a ? a->getElevation() : 0.0);
 469         }
 470
 471         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 472             thesky->get_cloud_layer(iLayer)
 473                 ->setCoverage(SGCloudLayer::SG_CLOUD_CLEAR);
 474             thesky->get_cloud_layer(iLayer)->get_layer3D()->clear();
 475         }
 476
 477         station += " 011000Z ";
 478         if( scenario == "Fair weather" ) {
 479                 fakeMetar = "15003KT 12SM SCT041 FEW200 20/08 Q1015 NOSIG";
 480                 //setLayer(0, 3300.0, "scattered", "cu");
 481         } else if( scenario == "Thunderstorm" ) {
 482                 fakeMetar = "15012KT 08SM TSRA SCT040 BKN070 20/12 Q0995";
 483                 setLayer(0, 4000.0, "scattered", "cb");
 484                 setLayer(1, 7000.0, "scattered", "ns");
 485         } else
 486                 return;
 487         FGMetar *m = new FGMetar( station + fakeMetar );
 488         update_metar_properties( m );
 489         update_env_config();
 490         // propagate aloft tables
 491         //_controller->reinit();
 492
 493         fgSetString("/environment/metar/last-metar", m->getData());
 494         // TODO:de-activate real metar updates
 495         if( scenario == "Fair weather" ) {
 496                 fgSetString("/environment/clouds/layer[1]/coverage", "cirrus");
 497         }
 498 }
 499
 500 void FGClouds::set_scenario(const char * sc) {
 501
 502         scenario = string(sc);
 503
 504 //        if(!rebuild_required && (scenario == last_scenario))
 505 //            return;
 506
 507         if( last_scenario == "none" ) {
 508         // save clouds and weather conditions
 509             SGPropertyNode *param = fgGetNode("/environment/config", true);
 510             copyProperties( param, last_env_config );
 511             param = fgGetNode("/environment/clouds", true);
 512             copyProperties( param, last_env_clouds );
 513         }
 514
 515         if( scenario == "METAR" ) {
 516             string realMetar = fgGetString("/environment/metar/real-metar", "");
 517
 518             if( realMetar != "" ) {
 519                 fgSetString("/environment/metar/last-metar", realMetar.c_str());
 520                 FGMetar *m = new FGMetar( realMetar );
 521                 update_metar_properties( m );
 522                 update_env_config();
 523                         // propagate aloft tables
 524                 _controller->reinit();
 525                 buildCloudLayers();
 526             }
 527         }
 528         else if( scenario == "none" ) {
 529         // restore clouds and weather conditions
 530             SGPropertyNode *param = fgGetNode("/environment/config", true);
 531             copyProperties( last_env_config, param );
 532             param = fgGetNode("/environment/clouds", true);
 533             copyProperties( last_env_clouds, param );
 534             fgSetDouble("/environment/metar/rain-norm", 0.0);
 535             fgSetDouble("/environment/metar/snow-norm", 0.0);
 536 //          update_env_config();
 537             // propagate aloft tables
 538             _controller->reinit();
 539             buildCloudLayers();
 540         }
 541         else {
 542             buildScenario( scenario );
 543             _controller->reinit();
 544             buildCloudLayers();
 545         }
 546
 547         last_scenario = scenario;
 548
 549         if( snd_lightning == NULL )
 550             init();
 551 }
 552
 553 const char * FGClouds::get_scenario(void) const
 554 {
 555     return scenario.c_str();
 556 }
 557
 558 void FGClouds::set_3dClouds(bool enable)
 559 {
 560     if (enable != clouds_3d_enabled) {
 561         clouds_3d_enabled = enable;
 562         buildCloudLayers();
 563     }
 564 }
 565
 566 bool FGClouds::get_3dClouds() const {
 567     return clouds_3d_enabled;
 568 }
 569