Vivian Meazza:

I've added another parameter to the submodel - wind.

It's activated by the entry <wind>true</wind> in the ../submodel.xml file.
If true, the submodel is affected by the local wind, otherwise not. The
parameter defaults to false. This is useful for exhausts and smoke, and
possibly all objects.

src/AIModel/AIBallistic.cxx

@@ -34,6 +34,7 @@ FGAIBallistic::FGAIBallistic(FGAIManager* mgr) {
     drag_area = 0.007;
     life_timer = 0.0;
 	gravity = 32;
+//	buoyancy = 64;
 	}
 
 FGAIBallistic::~FGAIBallistic() {
@@ -91,7 +92,17 @@ void FGAIBallistic::setBuoyancy(double fpss) {
    buoyancy = fpss;
 }
 
+void FGAIBallistic::setWind_from_east(double fps) {
+   wind_from_east = fps;
+}
 
+void FGAIBallistic::setWind_from_north(double fps) {
+   wind_from_north = fps;
+}
+
+void FGAIBallistic::setWind(bool val) {
+   wind = val;
+}
 void FGAIBallistic::Run(double dt) {
 
    life_timer += dt;
@@ -99,6 +110,8 @@ void FGAIBallistic::Run(double dt) {
 
    double speed_north_deg_sec;
    double speed_east_deg_sec;
+   double wind_speed_from_north_deg_sec;
+   double wind_speed_from_east_deg_sec;
       
    // the two drag calculations below assume sea-level density, 
    // mass of 0.03 slugs,  drag coeff of 0.295
@@ -112,9 +125,26 @@ void FGAIBallistic::Run(double dt) {
    speed_north_deg_sec = cos(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lat;
    speed_east_deg_sec  = sin(hdg / SG_RADIANS_TO_DEGREES) * hs / ft_per_deg_lon;
    
+   // convert wind speed (fps) to degrees per second
+   
+   if (!wind){
+      wind_from_north = 0;
+      wind_from_east = 0;
+	  }
+
+   wind_speed_from_north_deg_sec = wind_from_north / ft_per_deg_lat;
+   wind_speed_from_east_deg_sec  = wind_from_east / ft_per_deg_lon;
+   
+ 
    // set new position
-   pos.setlat( pos.lat() + speed_north_deg_sec * dt);
+//   pos.setlat( pos.lat() + (speed_north_deg_sec * dt)  );
-   pos.setlon( pos.lon() + speed_east_deg_sec * dt); 
+//   pos.setlon( pos.lon() + (speed_east_deg_sec * dt)  ); 
+ 
+ 
+   // set new position
+   
+   pos.setlat( pos.lat() + (speed_north_deg_sec - wind_speed_from_north_deg_sec) * dt );
+   pos.setlon( pos.lon() + (speed_east_deg_sec - wind_speed_from_east_deg_sec) * dt ); 
 
    // adjust vertical speed for acceleration of gravity
    vs -= (gravity - buoyancy) * dt;

src/AIModel/AIBallistic.hxx

@@ -41,7 +41,10 @@ public:
     void setStabilization( bool val );
     void setDragArea( double a );
     void setLife( double seconds );
-    void setBuoyancy( double fps2 );
+    void setBuoyancy( double fpss );
+	void setWind_from_east( double fps );
+	void setWind_from_north( double fps );
+	void setWind( bool val );
 	
 private:
 
@@ -53,6 +56,9 @@ private:
     double life_timer;      // seconds
 	double gravity;         // fps2
 	double buoyancy;        // fps2
+	double wind_from_east;  // fps
+	double wind_from_north; // fps
+	bool wind;              // if true, local wind will be applied to object
 		
     void Run(double dt);
 };

src/AIModel/AIManager.cxx

@@ -253,7 +253,8 @@ int FGAIManager::createShip( string path, FGAIFlightPlan* flightplan ) {
 
 int FGAIManager::createBallistic( string path, double latitude, double longitude,
                                   double altitude, double azimuth, double elevation,
-                                  double speed, double eda, double life, double buoyancy ) {
+                                  double speed, double eda, double life, double buoyancy,
+								  double wind_from_east, double wind_from_north, bool wind ) {
 
         FGAIBallistic* ai_ballistic = new FGAIBallistic(this);
         ai_list.push_back(ai_ballistic);
@@ -269,6 +270,9 @@ int FGAIManager::createBallistic( string path, double latitude, double longitude
         ai_ballistic->setDragArea(eda);
         ai_ballistic->setLife(life);
         ai_ballistic->setBuoyancy(buoyancy);
+		ai_ballistic->setWind_from_east(wind_from_east);
+		ai_ballistic->setWind_from_north(wind_from_north);
+		ai_ballistic->setWind(wind);
         ai_ballistic->init();
         ai_ballistic->bind();
         return ai_ballistic->getID();
@@ -308,7 +312,6 @@ int FGAIManager::createThermal( double latitude, double longitude,
         return ai_thermal->getID();
 }
 
-
 void FGAIManager::destroyObject( int ID ) {
         ai_list_itr = ai_list.begin();
         while(ai_list_itr != ai_list.end()) {
@@ -387,7 +390,8 @@ void FGAIManager::processScenario( string filename ) {
       } else if (en->aitype == "ballistic"){
         createBallistic( en->model_path, en->latitude, en->longitude,
                          en->altitude, en->azimuth, en->elevation, en->speed,
-                         en->eda, en->life, en->buoyancy );
+                         en->eda, en->life, en->buoyancy, en->wind_from_east,
+						 en-> wind_from_north, en->wind);
       }      
     }
   }

src/AIModel/AIManager.hxx

@@ -100,7 +100,10 @@ public:
                          double speed,          // in feet per second
                          double eda,            // equivalent drag area, ft2
                          double life,           // life span in seconds
-                         double buoyancy    // acceleration in ft per second2
+                         double buoyancy,       // acceleration due to buoyancy feet per second2
+                         double wind_from_east, // in feet per second
+						 double wind_from_north,  // in feet per second
+						 bool wind               // val
 						 );
      
     int createStorm( string path,        // path to exterior model
@@ -115,6 +118,18 @@ public:
                        double strength,    // in feet per second
                        double diameter );  // in feet
 
+    int createSmoke     ( string path,       // path to exterior model
+                         double latitude,   // in degrees -90 to 90
+                         double longitude,  // in degrees -180 to 180
+                         double altitude,   // in feet
+                         double azimuth,    // in degrees (same as heading)
+                         double elevation,  // in degrees (same as pitch)
+                         double speed,      // in feet per second
+                         double eda,        // equivalent drag area, ft2
+                        double life,        // life span in seconds
+                        double buoyancy    // acceleration due to buoyancy feet per second2
+                         );
+
                  
     void destroyObject( int ID );
 

src/AIModel/AIScenario.cxx

@@ -72,6 +72,9 @@ FGAIScenario::FGAIScenario(string filename)
      en->eda            = entry_node->getDoubleValue("eda", 0.007);
      en->life           = entry_node->getDoubleValue("life", 900.0);
 	 en->buoyancy       = entry_node->getDoubleValue("buoyancy", 0);
+	 en->wind_from_east = entry_node->getDoubleValue("wind_from_east", 0);
+	 en->wind_from_north = entry_node->getDoubleValue("wind_from_north", 0);
+	 en->wind            = entry_node->getBoolValue("wind", false);
    }
 
   entry_iterator = entries.begin();

src/AIModel/AIScenario.hxx

@@ -51,6 +51,9 @@ public:
    double eda;                // used by ballistic objects
    double life;               // life span in seconds
    double buoyancy;           // acceleration in ft per sec2
+   double wind_from_east;     // in feet per second
+   double wind_from_north;    // in feet per second
+   bool wind;
   } entry;
 
    FGAIScenario(string filename);

src/Systems/submodel.cxx

@@ -42,6 +42,8 @@ SubmodelSystem::init ()
 
     _user_speed_node = fgGetNode("/velocities/uBody-fps", true);
 
+    _user_wind_from_east_node  = fgGetNode("/environment/wind-from-east-fps",true);
+    _user_wind_from_north_node = fgGetNode("/environment/wind-from-north-fps",true);
 
     ai = (FGAIManager*)globals->get_subsystem("ai_model");
 }
@@ -86,12 +88,15 @@ SubmodelSystem::release (submodel* sm, double dt)
   if (sm->timer < sm->delay) return false;
   sm->timer = 0.0;
 
-  transform(sm);  // calculate submodel's initial conditions in world-coordinates
+  // calculate submodel's initial conditions in world-coordinates
+  transform(sm);
 
   //cout << "Creating a submodel." << endl; 
   int rval = ai->createBallistic( sm->model, IC.lat, IC.lon, IC.alt, IC.azimuth,
-                                  IC.elevation, IC.speed, sm->drag_area, sm->life,
+                                  IC.elevation, IC.speed, 
-				  sm-> buoyancy );
+				  sm->drag_area, sm->life,
+				  sm->buoyancy,
+				  IC.wind_from_east, IC.wind_from_north, sm->wind);
   //cout << "Submodel created." << endl;
   if (sm->count > 0) (sm->count)--; 
 
@@ -141,6 +146,7 @@ SubmodelSystem::load ()
      sm->drag_area      = entry_node->getDoubleValue("eda", 0.007);
      sm->life           = entry_node->getDoubleValue("life", 900.0);
      sm->buoyancy       = entry_node->getDoubleValue("buoyancy", 0);
+     sm->wind           = entry_node->getBoolValue  ("wind", false); 
 
      sm->trigger->setBoolValue(false);
      sm->timer = sm->delay;
@@ -165,9 +171,12 @@ SubmodelSystem::transform( submodel* sm)
   IC.azimuth =         _user_heading_node->getDoubleValue() + sm->yaw_offset;
   IC.elevation =       _user_pitch_node->getDoubleValue() + sm->pitch_offset;
   IC.speed =           _user_speed_node->getDoubleValue() + sm->speed;
+  IC.wind_from_east =  _user_wind_from_east_node->getDoubleValue();
+  IC.wind_from_north = _user_wind_from_north_node->getDoubleValue();
+//  IC.wind_from_east =  4;
+//   IC.wind_from_north = 5;
 
 }
 
-
 // end of submodel.cxx
 

src/Systems/submodel.hxx

@@ -44,6 +44,7 @@ public:
   double             drag_area; 
   double             life;
   double             buoyancy;
+  bool               wind;
     
  } submodel; 
 
@@ -54,6 +55,8 @@ public:
   double     azimuth;
   double     elevation;
   double     speed;
+  double     wind_from_east;
+  double     wind_from_north;
   
  } IC_struct;  
 
@@ -89,7 +92,8 @@ private:
     SGPropertyNode_ptr _user_roll_node;
     SGPropertyNode_ptr _user_yaw_node;
     SGPropertyNode_ptr _user_speed_node;
-
+	SGPropertyNode_ptr _user_wind_from_east_node;
+    SGPropertyNode_ptr _user_wind_from_north_node;
     FGAIManager* ai;
     IC_struct  IC;
 };