David Culp:

Here are some things I've added to the submodel code.

First, I added a first_time value that is true when the trigger is pressed and
false when the trigger is released.  The true value is also made false after
the first pass through release().  Release() then uses this to force the
first dt (per salvo) to be zero.  I was hoping this would make the submodel
appear closer to the airplane, but I don't notice a difference with the
tracers.  In a prior test I found that the first dt is about 2.5 times larger
than subsequent ones.  Maybe this will be effective with slower submodels,
like smoke, contrails, etc.

Secondly, I updated the IC.elevation and IC.azimuth calcs to correctly add in
the yaw and pitch offsets, corrected for bank angle.  Actually this is still
an estimation.  A proper calculation will sum the submodels vector with the
airplane's vector.  Until that's done only models which are fired forward
will have proper IC.

diff --git a/src/Systems/submodel.cxx b/src/Systems/submodel.cxx
index 28b7bc61cfc13f7ce99ce3ca290fd737cf79315f..3b012e54c4b61152f45fc073d4064ddb0a6bd908 100644 (file)
--- a/src/Systems/submodel.cxx
+++ b/src/Systems/submodel.cxx
@@ -43,6 +43,7 @@ SubmodelSystem::init ()
     _user_pitch_node =   fgGetNode("/orientation/pitch-deg", true);
     _user_roll_node =    fgGetNode("/orientation/roll-deg", true);
     _user_yaw_node =     fgGetNode("/orientation/yaw-deg", true);
+    _user_alpha_node =   fgGetNode("/orientation/alpha-deg", true);
 
     _user_speed_node = fgGetNode("/velocities/uBody-fps", true);
 
@@ -81,7 +82,9 @@ SubmodelSystem::update (double dt)
         if ((*submodel_iterator)->count != 0) {
           release( (*submodel_iterator), dt);
         } 
-    } 
+    } else {
+      (*submodel_iterator)->first_time = true;
+    }  
     ++submodel_iterator;
   }
    
@@ -94,9 +97,13 @@ SubmodelSystem::release (submodel* sm, double dt)
   if (sm->timer < sm->delay) return false;
   sm->timer = 0.0;
 
+  if (sm->first_time) {
+    dt = 0.0;
+    sm->first_time = false;
+  }
+
   transform(sm);  // calculate submodel's initial conditions in world-coordinates
 
-  //cout << "Creating a submodel." << endl; 
   FGAIModelEntity entity;
 
   entity.path = sm->model.c_str();
@@ -113,8 +120,7 @@ SubmodelSystem::release (submodel* sm, double dt)
   entity.wind_from_north = IC.wind_from_north;
   entity.wind = sm->wind;
   ai->createBallistic( &entity );
-
-  //cout << "Submodel created." << endl;
+ 
   if (sm->count > 0) (sm->count)--; 
 
   return true;                    
@@ -164,6 +170,7 @@ SubmodelSystem::load ()
      sm->life           = entry_node->getDoubleValue("life", 900.0);
      sm->buoyancy       = entry_node->getDoubleValue("buoyancy", 0);
      sm->wind           = entry_node->getBoolValue  ("wind", false); 
+     sm->first_time     = false;
 
      sm->trigger->setBoolValue(false);
      sm->timer = sm->delay;
@@ -171,16 +178,11 @@ SubmodelSystem::load ()
      sm->prop = fgGetNode("/systems/submodels/submodel", i, true);
      sm->prop->tie("count", SGRawValuePointer<int>(&(sm->count)));
 
-//      in[0] = sm->x_offset;
-//      in[1] = sm->y_offset;
-//      in[2] = sm->z_offset; 
- 
-
      submodels.push_back( sm );
    }
 
   submodel_iterator = submodels.begin();
-  // cout << submodels.size() << " submodels read." << endl;
+  
 }
 
 
@@ -193,19 +195,17 @@ SubmodelSystem::transform( submodel* sm)
   IC.lat =        _user_lat_node->getDoubleValue();    
   IC.lon =        _user_lon_node->getDoubleValue();       
   IC.alt =        _user_alt_node->getDoubleValue();    
-  IC.roll =      - _user_roll_node->getDoubleValue();   // rotation about x axis
-  IC.elevation =  _user_pitch_node->getDoubleValue();  // rotation about y axis
+  IC.roll =     - _user_roll_node->getDoubleValue();    // rotation about x axis
+  IC.elevation =  _user_pitch_node->getDoubleValue();   // rotation about y axis
   IC.azimuth =    _user_heading_node->getDoubleValue(); // rotation about z axis
   
-  IC.speed =           _user_speed_node->getDoubleValue() + sm->speed;
+  IC.speed =           _user_speed_node->getDoubleValue();
   IC.wind_from_east =  _user_wind_from_east_node->getDoubleValue();
   IC.wind_from_north = _user_wind_from_north_node->getDoubleValue();
   
   in[0] = sm->x_offset;
   in[1] = sm->y_offset;
   in[2] = sm->z_offset; 
-  
- 
 
 // pre-process the trig functions
 
@@ -216,49 +216,50 @@ SubmodelSystem::transform( submodel* sm)
     cosRz = cos(IC.azimuth * SG_DEGREES_TO_RADIANS);
     sinRz = sin(IC.azimuth * SG_DEGREES_TO_RADIANS);
 
-
 // set up the transform matrix
 
-    trans[0][0] =      cosRy * cosRz;
-    trans[0][1] =      -1 * cosRx * sinRz + sinRx * sinRy * cosRz ;
-    trans[0][2] =      sinRx * sinRz + cosRx * sinRy * cosRz;
+    trans[0][0] =  cosRy * cosRz;
+    trans[0][1] =  -1 * cosRx * sinRz + sinRx * sinRy * cosRz ;
+    trans[0][2] =  sinRx * sinRz + cosRx * sinRy * cosRz;
 
-    trans[1][0] =      cosRy * sinRz;
-    trans[1][1] =      cosRx * cosRz + sinRx * sinRy * sinRz;
-    trans[1][2] =      -1 * sinRx * cosRx + cosRx * sinRy * sinRz;
+    trans[1][0] =  cosRy * sinRz;
+    trans[1][1] =  cosRx * cosRz + sinRx * sinRy * sinRz;
+    trans[1][2] =  -1 * sinRx * cosRx + cosRx * sinRy * sinRz;
 
-    trans[2][0] =      -1 * sinRy;
-    trans[2][1] =      sinRx * cosRy;
-    trans[2][2] =   cosRx * cosRy;
+    trans[2][0] =  -1 * sinRy;
+    trans[2][1] =  sinRx * cosRy;
+    trans[2][2] =  cosRx * cosRy;
 
 
 // multiply the input and transform matrices
 
-//     for( int i=0; i<4; i++) {
-//             for( int j=0; j<4; j++ ) {
-//                     out[i] += in[j] * trans[i][j];
-//             }
-//     }
-
-out[0] = in[0] * trans[0][0] + in[1] * trans[0][1] + in[2] * trans[0][2];
-out[1] = in[0] * trans[1][0] + in[1] * trans[1][1] + in[2] * trans[1][2];
-out[2] = in[0] * trans[2][0] + in[1] * trans[2][1] + in[2] * trans[2][2];
-
-// convert ft to degrees of latitude
+   out[0] = in[0] * trans[0][0] + in[1] * trans[0][1] + in[2] * trans[0][2];
+   out[1] = in[0] * trans[1][0] + in[1] * trans[1][1] + in[2] * trans[1][2];
+   out[2] = in[0] * trans[2][0] + in[1] * trans[2][1] + in[2] * trans[2][2];
 
-    out[0] = out[0] /(366468.96 - 3717.12 * cos(IC.lat * SG_DEGREES_TO_RADIANS));
+   // convert ft to degrees of latitude
+   out[0] = out[0] /(366468.96 - 3717.12 * cos(IC.lat * SG_DEGREES_TO_RADIANS));
 
-// convert ft to degrees of longitude
+   // convert ft to degrees of longitude
+   out[1] = out[1] /(365228.16 * cos(IC.lat * SG_DEGREES_TO_RADIANS));
 
-    out[1] = out[1] /(365228.16 * cos(IC.lat * SG_DEGREES_TO_RADIANS));
-
-
-    IC.lat += out[0];
-    IC.lon += out[1];
-    IC.alt += out[2];
-    IC.elevation += sm->pitch_offset;
-    IC.azimuth   += sm->yaw_offset;
+   // set submodel initial position
+   IC.lat += out[0];
+   IC.lon += out[1];
+   IC.alt += out[2];
 
+   // get aircraft velocity vector angles in XZ and XY planes
+    //double alpha = _user_alpha_node->getDoubleValue();
+    //double velXZ = IC.elevation - alpha * cosRx;
+    //double velXY = IC.azimuth - (IC.elevation - alpha * sinRx);
+   
+   // Get submodel initial velocity vector angles in XZ and XY planes.
+   // This needs to be fixed. This vector should be added to aircraft's vector. 
+   IC.elevation += (sm->pitch_offset * cosRx) + (sm->yaw_offset * sinRx);
+   IC.azimuth   += (sm->yaw_offset * cosRx) - (sm->pitch_offset * sinRx);
+ 
+   // For now assume vector is close to airplane's vector.  This needs to be fixed.
+   IC.speed += sm->speed; 
 
 }
 

diff --git a/src/Systems/submodel.hxx b/src/Systems/submodel.hxx
index 8acb6b47ce207f6fb89e012e95a75b11ea4cc68b..499eb00494eae3c90b8d242abaa2c5b2746e6ae6 100644 (file)
--- a/src/Systems/submodel.hxx
+++ b/src/Systems/submodel.hxx
@@ -46,7 +46,7 @@ public:
   double             life;
   double             buoyancy;
   bool               wind;
-    
+  bool               first_time;
  } submodel; 
 
  typedef struct {
@@ -59,7 +59,6 @@ public:
   double     speed;
   double     wind_from_east;
   double     wind_from_north;
-  
  } IC_struct;  
 
     SubmodelSystem ();
@@ -108,11 +107,13 @@ private:
     SGPropertyNode* _user_pitch_node;
     SGPropertyNode* _user_roll_node;
     SGPropertyNode* _user_yaw_node;
+    SGPropertyNode* _user_alpha_node;
     SGPropertyNode* _user_speed_node;
     SGPropertyNode* _user_wind_from_east_node;
     SGPropertyNode* _user_wind_from_north_node;
     FGAIManager* ai;
     IC_struct  IC;
+
 };
 
 #endif // __SYSTEMS_SUBMODEL_HXX