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     clouds_3d_enabled(false),
  55     last_scenario( "unset" ),
  56     last_env_config( new SGPropertyNode() ),
  57     last_env_clouds( new SGPropertyNode() )
  58 {
  59         update_event = 0;
  60 }
  61 FGClouds::~FGClouds() {
  62 }
  63
  64 int FGClouds::get_update_event(void) const {
  65         return update_event;
  66 }
  67 void FGClouds::set_update_event(int count) {
  68         update_event = count;
  69         buildCloudLayers();
  70 }
  71
  72 void FGClouds::init(void) {
  73         if( snd_lightning == NULL ) {
  74                 snd_lightning = new SGSoundSample(globals->get_fg_root().c_str(), "Sounds/thunder.wav");
  75                 snd_lightning->set_max_dist(7000.0f);
  76                 snd_lightning->set_reference_dist(3000.0f);
  77                 SGSoundMgr *soundMgr = globals->get_soundmgr();
  78                 soundMgr->add( snd_lightning, "thunder" );
  79                 sgEnviro.set_soundMgr( soundMgr );
  80         }
  81 }
  82
  83 void FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode  *box_def_root, const string& name, sgVec3 pos, SGCloudField *layer) {
  84         SGPropertyNode *box_def=NULL;
  85         SGPropertyNode *cld_def=NULL;
  86
  87         SGPath texture_root = globals->get_fg_root();
  88         texture_root.append("Textures");
  89         texture_root.append("Sky");
  90
  91         box_def = box_def_root->getChild(name.c_str());
  92
  93         string base_name = name.substr(0,2);
  94         if( !box_def ) {
  95                 if( name[2] == '-' ) {
  96                         box_def = box_def_root->getChild(base_name.c_str());
  97                 }
  98                 if( !box_def )
  99                         return;
 100         }
 101
 102         for(int i = 0; i < box_def->nChildren() ; i++) {
 103                 SGPropertyNode *abox = box_def->getChild(i);
 104                 if( strcmp(abox->getName(), "box") == 0) {
 105                         double x = abox->getDoubleValue("x") + pos[0];
 106                         double y = abox->getDoubleValue("y") + pos[1];
 107                         double z = abox->getDoubleValue("z") + pos[2];
 108                         SGVec3f newpos = SGVec3f(x, z, y);
 109
 110                         string type = abox->getStringValue("type", "cu-small");
 111
 112                         cld_def = cloud_def_root->getChild(type.c_str());
 113                         if ( !cld_def ) return;
 114
 115                         double min_width = cld_def->getDoubleValue("min-cloud-width-m", 500.0);
 116                         double max_width = cld_def->getDoubleValue("max-cloud-width-m", 1000.0);
 117                         double min_height = cld_def->getDoubleValue("min-cloud-height-m", min_width);
 118                         double max_height = cld_def->getDoubleValue("max-cloud-height-m", max_width);
 119                         double min_sprite_width = cld_def->getDoubleValue("min-sprite-width-m", 200.0);
 120                         double max_sprite_width = cld_def->getDoubleValue("max-sprite-width-m", min_sprite_width);
 121                         double min_sprite_height = cld_def->getDoubleValue("min-sprite-height-m", min_sprite_width);
 122                         double max_sprite_height = cld_def->getDoubleValue("max-sprite-height-m", max_sprite_width);
 123                         int num_sprites = cld_def->getIntValue("num-sprites", 20);
 124                         int num_textures_x = cld_def->getIntValue("num-textures-x", 1);
 125                         int num_textures_y = cld_def->getIntValue("num-textures-y", 1);
 126                         double bottom_shade = cld_def->getDoubleValue("bottom-shade", 1.0);
 127                         string texture = cld_def->getStringValue("texture", "cl_cumulus.rgb");
 128
 129                         SGNewCloud *cld =
 130                                 new SGNewCloud(type,
 131                                                texture_root,
 132                                                texture,
 133                                                min_width,
 134                                                max_width,
 135                                                min_height,
 136                                                max_height,
 137                                                min_sprite_width,
 138                                                max_sprite_width,
 139                                                min_sprite_height,
 140                                                max_sprite_height,
 141                                                bottom_shade,
 142                                                num_sprites,
 143                                                num_textures_x,
 144                                                num_textures_y);
 145                         layer->addCloud(newpos, cld);
 146                 }
 147         }
 148 }
 149
 150 void FGClouds::buildLayer(int iLayer, const string& name, double alt, double coverage) {
 151         struct {
 152                 string name;
 153                 double count;
 154         } tCloudVariety[20];
 155         int CloudVarietyCount = 0;
 156         double totalCount = 0.0;
 157
 158         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 159         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 160         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 161         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 162         layer->clear();
 163
 164         // If we don't have the required properties, then render the cloud in 2D
 165         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 166             layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL)
 167         {
 168                 thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 169                 return;
 170         }
 171
 172         // If we can't find a definition for this cloud type, then render the cloud in 2D
 173         SGPropertyNode *layer_def=NULL;
 174         layer_def = layer_def_root->getChild(name.c_str());
 175         if( !layer_def ) {
 176                 if( name[2] == '-' ) {
 177                         string base_name = name.substr(0,2);
 178                         layer_def = layer_def_root->getChild(base_name.c_str());
 179                 }
 180                 if( !layer_def )
 181                 {
 182                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 183                         return;
 184                 }
 185         }
 186
 187         // At this point, we know we've got some 3D clouds to generate.
 188         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 189
 190         double grid_x_size = layer_def->getDoubleValue("grid-x-size", 1000.0);
 191         double grid_y_size = layer_def->getDoubleValue("grid-y-size", 1000.0);
 192         double grid_x_rand = layer_def->getDoubleValue("grid-x-rand", grid_x_size);
 193         double grid_y_rand = layer_def->getDoubleValue("grid-y-rand", grid_y_size);
 194         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 195
 196         for(int i = 0; i < layer_def->nChildren() ; i++) {
 197                 SGPropertyNode *acloud = layer_def->getChild(i);
 198                 if( strcmp(acloud->getName(), "cloud") == 0) {
 199                         string cloud_name = acloud->getStringValue("name");
 200                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 201                         double count = acloud->getDoubleValue("count", 1.0);
 202                         tCloudVariety[CloudVarietyCount].count = count;
 203                         int variety = 0;
 204                         cloud_name = cloud_name + "-%d";
 205                         char variety_name[50];
 206                         do {
 207                                 variety++;
 208                                 snprintf(variety_name, sizeof(variety_name), cloud_name.c_str(), variety);
 209                         } while( box_def_root->getChild(variety_name, 0, false) );
 210
 211                         totalCount += count;
 212                         if( CloudVarietyCount < 20 )
 213                                 CloudVarietyCount++;
 214                 }
 215         }
 216         totalCount = 1.0 / totalCount;
 217
 218         for(double px = 0.0; px < SGCloudField::fieldSize; px += grid_x_size) {
 219                 for(double py = 0.0; py < SGCloudField::fieldSize; py += grid_y_size) {
 220                         double x = px + grid_x_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 221                         double y = py + grid_y_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 222                         double z = grid_z_rand * (sg_random() - 0.5);
 223
 224                         if (sg_random() < coverage)
 225                         {
 226                             double choice = sg_random();
 227
 228                             for(int i = 0; i < CloudVarietyCount ; i ++) {
 229                                     choice -= tCloudVariety[i].count * totalCount;
 230                                     if( choice <= 0.0 ) {
 231                                             sgVec3 pos={x,z,y};
 232
 233                                             buildCloud(cloud_def_root,
 234                                                        box_def_root,
 235                                                        tCloudVariety[i].name,
 236                                                        pos,
 237                                                        layer);
 238                                             break;
 239                                     }
 240                             }
 241                         }
 242                 }
 243         }
 244
 245         // Now we've built any clouds, enable them and set the density (coverage)
 246         //layer->setCoverage(coverage);
 247         //layer->applyCoverage();
 248         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 249 }
 250
 251 void FGClouds::buildCloudLayers(void) {
 252         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 253
 254         double wind_speed_kt     = metar_root->getDoubleValue("wind-speed-kt");
 255         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 256         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 257         double pressure_mb              = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 258
 259         double dewp = pow(10.0, 7.5 * dewpoint_degc / (237.7 + dewpoint_degc));
 260         double temp = pow(10.0, 7.5 * temperature_degc / (237.7 + temperature_degc));
 261         double rel_humidity = dewp * 100 / temp;
 262
 263         // formule d'Epsy, base d'un cumulus
 264         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 265         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 266
 267         bool cu_seen = false;
 268
 269         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 270                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 271
 272                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 273                 double alt_m = alt_ft * SG_FEET_TO_METER;
 274                 string coverage = cloud_root->getStringValue("coverage");
 275
 276
 277                 double coverage_norm = 0.0;
 278                 if( coverage == "few" )
 279                         coverage_norm = 2.0/8.0;        // <1-2
 280                 else if( coverage == "scattered" )
 281                         coverage_norm = 4.0/8.0;        // 3-4
 282                 else if( coverage == "broken" )
 283                         coverage_norm = 6.0/8.0;        // 5-7
 284                 else if( coverage == "overcast" )
 285                         coverage_norm = 8.0/8.0;        // 8
 286
 287                 string layer_type = "nn";
 288                 if( coverage == "cirrus" ) {
 289                         layer_type = "ci";
 290                 } else if( alt_ft > 16500 ) {
 291 //                      layer_type = "ci|cs|cc";
 292                         layer_type = "ci";
 293                 } else if( alt_ft > 6500 ) {
 294 //                      layer_type = "as|ac|ns";
 295                         layer_type = "ac";
 296                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 297                                 layer_type = "ns";
 298                 } else {
 299 //                      layer_type = "st|cu|cb|sc";
 300                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 301                                 // +/- 20% from cumulus probable base
 302                                 layer_type = "cu";
 303                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 304                                 // +/- 20% from stratus probable base
 305                                 layer_type = "st";
 306                         } else {
 307                                 // above formulae is far from perfect
 308                                 if ( alt_ft < 2000 )
 309                                         layer_type = "st";
 310                                 else if( alt_ft < 4500 )
 311                                         layer_type = "cu";
 312                                 else
 313                                         layer_type = "sc";
 314                         }
 315                 }
 316
 317                 buildLayer(iLayer, layer_type, alt_m, coverage_norm);
 318         }
 319 }
 320
 321 // copy from FGMetarEnvironmentCtrl until better
 322 void
 323 FGClouds::update_metar_properties( const FGMetar *m )
 324 {
 325     int i;
 326     int j;
 327     double d;
 328     char s[128];
 329
 330     fgSetString("/environment/metar/station-id", m->getId());
 331     fgSetDouble("/environment/metar/min-visibility-m",
 332                 m->getMinVisibility().getVisibility_m() );
 333     fgSetDouble("/environment/metar/max-visibility-m",
 334                 m->getMaxVisibility().getVisibility_m() );
 335
 336     const SGMetarVisibility *dirvis = m->getDirVisibility();
 337     for (i = 0; i < 8; i++, dirvis++) {
 338         const char *min = "/environment/metar/visibility[%d]/min-m";
 339         const char *max = "/environment/metar/visibility[%d]/max-m";
 340
 341         d = dirvis->getVisibility_m();
 342
 343         snprintf(s, 128, min, i);
 344         fgSetDouble(s, d);
 345         snprintf(s, 128, max, i);
 346         fgSetDouble(s, d);
 347     }
 348
 349     fgSetInt("/environment/metar/base-wind-range-from",
 350              m->getWindRangeFrom() );
 351     fgSetInt("/environment/metar/base-wind-range-to",
 352              m->getWindRangeTo() );
 353     fgSetDouble("/environment/metar/base-wind-speed-kt",
 354                 m->getWindSpeed_kt() );
 355     fgSetDouble("/environment/metar/gust-wind-speed-kt",
 356                 m->getGustSpeed_kt() );
 357     fgSetDouble("/environment/metar/temperature-degc",
 358                 m->getTemperature_C() );
 359     fgSetDouble("/environment/metar/dewpoint-degc",
 360                 m->getDewpoint_C() );
 361     fgSetDouble("/environment/metar/rel-humidity-norm",
 362                 m->getRelHumidity() );
 363     fgSetDouble("/environment/metar/pressure-inhg",
 364                 m->getPressure_inHg() );
 365
 366     vector<SGMetarCloud> cv = m->getClouds();
 367     vector<SGMetarCloud>::const_iterator cloud;
 368
 369     // Load into both the METAR and environment properties to stop interpolation
 370     const char *cl[] = {"/environment/metar/clouds/layer[%i]",
 371                         "/environment/clouds/layer[%i]"};
 372
 373     for (j = 0; j < 2; j++)
 374     {
 375         for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
 376             const char *coverage_string[5] =
 377                 { "clear", "few", "scattered", "broken", "overcast" };
 378             const double thickness[5] = { 0, 65, 600,750, 1000};
 379             int q;
 380
 381             snprintf(s, 128, cl[j], i);
 382             strncat(s, "/coverage", 128);
 383             q = cloud->getCoverage();
 384             fgSetString(s, coverage_string[q] );
 385
 386             snprintf(s, 128, cl[j], i);
 387             strncat(s, "/elevation-ft", 128);
 388             fgSetDouble(s, cloud->getAltitude_ft() + station_elevation_ft);
 389
 390             snprintf(s, 128, cl[j], i);
 391             strncat(s, "/thickness-ft", 128);
 392             fgSetDouble(s, thickness[q]);
 393
 394             snprintf(s, 128, cl[j], i);
 395             strncat(s, "/span-m", 128);
 396             fgSetDouble(s, 40000.0);
 397         }
 398
 399         for (; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 400
 401
 402             snprintf(s, 128, cl[j], i);
 403             strncat(s, "/coverage", 128);
 404             fgSetString(s, "clear");
 405
 406             snprintf(s, 128, cl[j], i);
 407             strncat(s, "/elevation-ft", 128);
 408             fgSetDouble(s, -9999);
 409
 410             snprintf(s, 128, cl[j], i);
 411             strncat(s, "/thickness-ft", 128);
 412             fgSetDouble(s, 0);
 413
 414             snprintf(s, 128, cl[j], i);
 415             strncat(s, "/span-m", 128);
 416             fgSetDouble(s, 40000.0);
 417         }
 418     }
 419
 420     fgSetDouble("/environment/metar/rain-norm", m->getRain());
 421     fgSetDouble("/environment/metar/hail-norm", m->getHail());
 422     fgSetDouble("/environment/metar/snow-norm", m->getSnow());
 423     fgSetBool("/environment/metar/snow-cover", m->getSnowCover());
 424 }
 425
 426 void
 427 FGClouds::update_env_config ()
 428 {
 429     fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
 430                  fgGetDouble("/environment/metar/base-wind-range-to"),
 431                  fgGetDouble("/environment/metar/base-wind-speed-kt"),
 432                  fgGetDouble("/environment/metar/gust-wind-speed-kt") );
 433
 434     fgDefaultWeatherValue( "visibility-m",
 435                            fgGetDouble("/environment/metar/min-visibility-m") );
 436 #if 0
 437     set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
 438                           station_elevation_ft );
 439     set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
 440                               station_elevation_ft );
 441 #endif
 442     fgDefaultWeatherValue( "pressure-sea-level-inhg",
 443                            fgGetDouble("/environment/metar/pressure-inhg") );
 444 }
 445
 446 void FGClouds::setLayer( int iLayer, float alt_ft, const string& coverage, const string& layer_type ) {
 447         double coverage_norm = 0.0;
 448         if( coverage == "few" )
 449                 coverage_norm = 2.0/8.0;        // <1-2
 450         else if( coverage == "scattered" )
 451                 coverage_norm = 4.0/8.0;        // 3-4
 452         else if( coverage == "broken" )
 453                 coverage_norm = 6.0/8.0;        // 5-7
 454         else if( coverage == "overcast" )
 455                 coverage_norm = 8.0/8.0;        // 8
 456
 457         buildLayer(iLayer, layer_type, station_elevation_ft + alt_ft * SG_FEET_TO_METER, coverage_norm);
 458 }
 459
 460 void FGClouds::buildScenario( const string& scenario ) {
 461         string fakeMetar="";
 462         string station = fgGetString("/environment/metar/station-id", "XXXX");
 463
 464         // fetch station elevation if exists
 465         if( station == "XXXX" )
 466             station_elevation_ft = fgGetDouble("/position/ground-elev-m", 0.0);
 467         else {
 468             const FGAirport* a = FGAirport::findByIdent(station);
 469             station_elevation_ft = (a ? a->getElevation() : 0.0);
 470         }
 471
 472         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 473             thesky->get_cloud_layer(iLayer)
 474                 ->setCoverage(SGCloudLayer::SG_CLOUD_CLEAR);
 475             thesky->get_cloud_layer(iLayer)->get_layer3D()->clear();
 476         }
 477
 478         station += " 011000Z ";
 479         if( scenario == "Fair weather" ) {
 480                 fakeMetar = "15003KT 12SM SCT041 FEW200 20/08 Q1015 NOSIG";
 481                 //setLayer(0, 3300.0, "scattered", "cu");
 482         } else if( scenario == "Thunderstorm" ) {
 483                 fakeMetar = "15012KT 08SM TSRA SCT040 BKN070 20/12 Q0995";
 484                 setLayer(0, 4000.0, "scattered", "cb");
 485                 setLayer(1, 7000.0, "scattered", "ns");
 486         } else
 487                 return;
 488         FGMetar *m = new FGMetar( station + fakeMetar );
 489         update_metar_properties( m );
 490         update_env_config();
 491         // propagate aloft tables
 492         //_controller->reinit();
 493
 494         fgSetString("/environment/metar/last-metar", m->getData());
 495         // TODO:de-activate real metar updates
 496         if( scenario == "Fair weather" ) {
 497                 fgSetString("/environment/clouds/layer[1]/coverage", "cirrus");
 498         }
 499 }
 500
 501 void FGClouds::set_scenario(const char * sc) {
 502
 503         scenario = string(sc);
 504
 505 //        if(!rebuild_required && (scenario == last_scenario))
 506 //            return;
 507
 508         if( last_scenario == "none" ) {
 509         // save clouds and weather conditions
 510             SGPropertyNode *param = fgGetNode("/environment/config", true);
 511             copyProperties( param, last_env_config );
 512             param = fgGetNode("/environment/clouds", true);
 513             copyProperties( param, last_env_clouds );
 514         }
 515
 516         if( scenario == "METAR" ) {
 517             string realMetar = fgGetString("/environment/metar/real-metar", "");
 518
 519             if( realMetar != "" ) {
 520                 fgSetString("/environment/metar/last-metar", realMetar.c_str());
 521                 FGMetar *m = new FGMetar( realMetar );
 522                 update_metar_properties( m );
 523                 update_env_config();
 524                         // propagate aloft tables
 525                 _controller->reinit();
 526                 buildCloudLayers();
 527             }
 528         }
 529         else if( scenario == "none" ) {
 530         // restore clouds and weather conditions
 531             SGPropertyNode *param = fgGetNode("/environment/config", true);
 532             copyProperties( last_env_config, param );
 533             param = fgGetNode("/environment/clouds", true);
 534             copyProperties( last_env_clouds, param );
 535             fgSetDouble("/environment/metar/rain-norm", 0.0);
 536             fgSetDouble("/environment/metar/snow-norm", 0.0);
 537 //          update_env_config();
 538             // propagate aloft tables
 539             _controller->reinit();
 540             buildCloudLayers();
 541         }
 542         else {
 543             buildScenario( scenario );
 544             _controller->reinit();
 545             buildCloudLayers();
 546         }
 547
 548         last_scenario = scenario;
 549
 550         if( snd_lightning == NULL )
 551             init();
 552 }
 553
 554 const char * FGClouds::get_scenario(void) const
 555 {
 556     return scenario.c_str();
 557 }
 558
 559 void FGClouds::set_3dClouds(bool enable)
 560 {
 561     if (enable != clouds_3d_enabled) {
 562         clouds_3d_enabled = enable;
 563         buildCloudLayers();
 564     }
 565 }
 566
 567 bool FGClouds::get_3dClouds() const {
 568     return clouds_3d_enabled;
 569 }
 570