Hi Maik, Am Donnerstag, den 21.12.2006, 02:14 +0100 schrieb Maik Justus: > Hi > > here is a patch that YASim gears make use of the ground properties > (friction, bumpiness, etc). > It enhances the gears, that you can define different gears for "on > water" and for "not on water". > And you can define "inverse-speed-spring-is-doubled", with this the gear > extends with increasing speed which can be used for lifting the airplane > out of the water with increasing speed. The friction at this speed is > reduced by "reduce-friction-by-speed" to simulate (fake?) the reduced drag. > That's great news! I will continue to work on the Albatros Model and the JU-52 on floats is also within reach.
Thanks a lot! Detlef > This patch is tested only a very bit on default scenery with only one > aircraft. It is probably not ready for cvs. (all enhancements for water > aircrafts are fully untested...) I hope I find the time to test the > beaver in the next days. > > Maik > > Maik Justus schrieb am 20.12.2006 01:19: > > Hi Melchior, > > > > thanks for the info. I will try to make use of this with the yasim gears. > > > > Maik > > > > > > Melchior FRANZ schrieb am 20.12.2006 00:56: > > > >> * Maik Justus -- Wednesday 20 December 2006 00:47: > >> > >> > >>> does anyone know, how to access the ground properties by the FDM? > >>> > >>> > >> Looks like the groundcache provides this: > >> > >> bool > >> FGGroundCache::get_agl(double t, const SGVec3d& dpt, double max_altoff, > >> SGVec3d& contact, SGVec3d& normal, SGVec3d& vel, > >> int *type, const SGMaterial** material, double *agl) > >> > >> > >> The ground cache is already used by JSBSim and YASim for gear contact. > >> See simgear/scene/material/mat.hxx for SGMaterial. It has methods to > >> read friction/bumpiness/... > >> > >> m. > >> > >> > > > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of IT > > Join SourceForge.net's Techsay panel and you'll get the chance to share your > > opinions on IT & business topics through brief surveys - and earn cash > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > _______________________________________________ > > Flightgear-devel mailing list > > Flightgear-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > > > > > > einfaches Textdokument-Anlage (README.yasim.diff) > Index: README.yasim > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/data/Docs/README.yasim,v > retrieving revision 1.17 > diff -u -p -r1.17 README.yasim > --- README.yasim 10 Nov 2006 18:06:24 -0000 1.17 > +++ README.yasim 21 Dec 2006 00:58:14 -0000 > @@ -44,6 +44,15 @@ fuselage: This defines a tubelike struct > expressed as a fraction (0-1) of the width value. > midpoint: The location of the widest part of the fuselage, > expressed as a fraction of the distance between A and B. > + idrag: Multiplier for the "induced drag" generated by this > + object. Default is one. With idrag=0 the fuselage > + generates only drag. > + cx,cy,cz: Factors for the generated drag in the fuselages "local > + coordinate system" with x pointing from end to front, > + z perpendicular to x with y=0 in the aircraft coordinate > + system. E.g. for a fuselage of a height of 2 times the > + width you can define cy=2 and (due to the doubled front > + surface) cx=2. > > wing: This defines the main wing of the aircraft. You can have > only one (but see below about using vstab objects for extra > @@ -312,6 +321,23 @@ gear: Defines a landing gear. Accep > unstable. If you can't make the gear stop > bouncing with this number, try increasing the > compression length instead. > + only-on-water: if ths set to "1" the gear will be ignored if > + not on water. Defaults to "0" > + not-on-water: if ths set to "0" the gear will be ignored if > + on water. Defaults to "1" > + inverse-speed-spring-is-doubled: At this speed (the inverse of > + the speed must be given) the spring constant > + is doubled. The idea is, to use this on water to > + simulate the speed dependend lift of a float. > + Defaults to "0" > + reduce-friction-by-speed: at the speed given by the last tag the > + friction is reduced by this relative value. Can be > + used for simulating (fakeing) the reduced drag of > + a lifted float. E.g. if you secifiy this value to > + "0.2" the friction is reduced by 20% at the speed > + defined by the last tag and by 40% at the double > + speed. Defaults to "0" > + > > launchbar: Defines a catapult launchbar or strop. > x,y,z: The location of the mount point of the launch bar or > @@ -481,7 +507,6 @@ rotor: A rotor. Used for simulating h > A value stall gives the fraction of the rotor in stall > (weighted by the fraction the have on lift and drag > without stall). Use this for modifying the rotor-sound. > - The torque property has a bug. > x,y,z: The position of the rotor center > nx,ny,nz: The normal of the rotor (pointing upwards, will be > normalized by the computer) > @@ -555,11 +580,6 @@ rotor: A rotor. Used for simulating h > is stall. In the range between this incidences it is > interpolated linear. > > - The airfoil of the rotor can be described in two ways. First you > - can define the needed power for different pitch values and the > - total lift force at a user-defined pitch value. Don't use pitch > - values greater than the stall incidence. You could get strange > - results. > > pitch-a: > pitch-b: collective incidence angles, If you start flightgear > @@ -573,6 +593,7 @@ rotor: A rotor. Used for simulating h > coefficients instead (see below) and adjust the lift with > rotor-correction-factor. > > + The airfoil of the rotor is described as follows: > The way is to define the lift and drag coefficients directly. > Without stall the c-lift of the profile is assumed to be > sin(incidence-"airfoil-incidence-no-lift")*liftcoef; > @@ -688,7 +709,11 @@ rotorgear: If you are using one ore more > yasimliftfactor: the solver is not working with rotor-aircrafts. > Therefore you have to specify the results yourself. > 10 for drag and 140 for lift seem to be good starting > - values. > + values. Although the solve is not invoked for aircrafts > + with at least one rotor, you need to specifiy the cruise > + and the approach seetings. The approach speed is needed to > + calculate the gear springs. Use a speed of approx. > 50knots. > + They do not need to match any real value. > > The rotorgear needs a <control> subelement for the engine > (ROTORGEARENGINEON) and can have a <control> subelement for the > einfaches Textdokument-Anlage (gear.diff) > Index: flight.cxx > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/flight.cxx,v > retrieving revision 1.28 > diff -u -p -r1.28 flight.cxx > --- flight.cxx 26 Jul 2006 14:18:06 -0000 1.28 > +++ flight.cxx 21 Dec 2006 01:04:11 -0000 > @@ -870,6 +870,34 @@ FGInterface::get_agl_m(double t, const d > return ret; > } > > +bool > +FGInterface::get_agl_m(double t, const double pt[3], > + double contact[3], double normal[3], double vel[3], > + int *type, double *loadCapacity, > + double *frictionFactor, double *agl, > + double *rollingFritction, double *loadResistance, > + double *bumpiness, bool *isSolid) > +{ > + const SGMaterial* material; > + bool ret = ground_cache.get_agl(t, pt, 2.0, contact, normal, vel, type, > + &material, agl); > + if (material) { > + *loadCapacity = material->get_load_resistence(); > + *frictionFactor = material->get_friction_factor(); > + *rollingFritction = material->get_rolling_friction(); > + *loadResistance = material->get_load_resistence(); > + *bumpiness = material->get_bumpiness(); > + *isSolid = material->get_solid(); > + } else { > + *loadCapacity = DBL_MAX; > + *frictionFactor = 1.0; > + *rollingFritction = 0.02; > + *loadResistance = DBL_MAX; > + *bumpiness = 0.0; > + } > + return ret; > +} > + > // Legacy interface just kept because of JSBSim > bool > FGInterface::get_agl_ft(double t, const double pt[3], > Index: flight.hxx > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/flight.hxx,v > retrieving revision 1.13 > diff -u -p -r1.13 flight.hxx > --- flight.hxx 11 Jun 2006 13:34:19 -0000 1.13 > +++ flight.hxx 21 Dec 2006 01:04:16 -0000 > @@ -1128,6 +1128,12 @@ public: > double contact[3], double normal[3], double vel[3], > int *type, double *loadCapacity, > double *frictionFactor, double *agl); > + bool get_agl_m(double t, const double pt[3], > + double contact[3], double normal[3], double vel[3], > + int *type, double *loadCapacity, > + double *frictionFactor, double *agl, > + double *rollingFritction, double *loadResistance, > + double *bumpiness,bool *isSolid); > bool get_agl_ft(double t, const double pt[3], > double contact[3], double normal[3], double vel[3], > int *type, double *loadCapacity, > Index: YASim/FGFDM.cpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/FGFDM.cpp,v > retrieving revision 1.44.2.1 > diff -u -p -r1.44.2.1 FGFDM.cpp > --- YASim/FGFDM.cpp 18 Dec 2006 21:32:56 -0000 1.44.2.1 > +++ YASim/FGFDM.cpp 21 Dec 2006 01:04:32 -0000 > @@ -273,6 +273,10 @@ void FGFDM::startElement(const char* nam > g->setDynamicFriction(attrf(a, "dfric", 0.7)); > g->setSpring(attrf(a, "spring", 1)); > g->setDamping(attrf(a, "damp", 1)); > + if(attrb(a,"only-on-water"))g->setOnlyOnWater(1); > + if(attrb(a,"not-on-water"))g->setNotOnWater(1); > + g->setInverseSpeedSpringIsDoubled(attrf(a, > "inverse-speed-spring-is-doubled", 0)); > + g->setReduceFrictionBySpeed(attrf(a, "reduce-friction-by-speed", 0)); > _airplane.addGear(g); > } else if(eq(name, "hook")) { > Hook* h = new Hook(); > Index: YASim/FGGround.cpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/FGGround.cpp,v > retrieving revision 1.2 > diff -u -p -r1.2 FGGround.cpp > --- YASim/FGGround.cpp 18 Feb 2005 12:40:39 -0000 1.2 > +++ YASim/FGGround.cpp 21 Dec 2006 01:04:32 -0000 > @@ -35,6 +35,29 @@ void FGGround::getGroundPlane(const doub > for(int i=0; i<3; i++) vel[i] = dvel[i]; > } > > +void FGGround::getGroundPlane(const double pos[3], > + double plane[4], float vel[3], > + int *type, > + double *frictionFactor, > + double *rollingFriction, > + double *loadCapacity, > + double *loadResistance, > + double *bumpiness, > + bool *isSolid) > +{ > + // Return values for the callback. > + double agl; > + double cp[3], dvel[3]; > + _iface->get_agl_m(_toff, pos, cp, plane, dvel, > + type, loadCapacity, frictionFactor, &agl, > + rollingFriction,loadResistance,bumpiness,isSolid); > + > + // The plane below the actual contact point. > + plane[3] = plane[0]*cp[0] + plane[1]*cp[1] + plane[2]*cp[2]; > + > + for(int i=0; i<3; i++) vel[i] = dvel[i]; > +} > + > bool FGGround::caughtWire(const double pos[4][3]) > { > return _iface->caught_wire_m(_toff, pos); > Index: YASim/FGGround.hpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/FGGround.hpp,v > retrieving revision 1.1 > diff -u -p -r1.1 FGGround.hpp > --- YASim/FGGround.hpp 17 Feb 2005 10:37:26 -0000 1.1 > +++ YASim/FGGround.hpp 21 Dec 2006 01:04:32 -0000 > @@ -18,6 +18,16 @@ public: > virtual void getGroundPlane(const double pos[3], > double plane[4], float vel[3]); > > + virtual void FGGround::getGroundPlane(const double pos[3], > + double plane[4], float vel[3], > + int *type, > + double *frictionFactor, > + double *rollingFriction, > + double *loadCapacity, > + double *loadResistance, > + double *bumpiness, > + bool *isSolid); > + > virtual bool caughtWire(const double pos[4][3]); > > virtual bool getWire(double end[2][3], float vel[2][3]); > Index: YASim/Gear.cpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Gear.cpp,v > retrieving revision 1.7 > diff -u -p -r1.7 Gear.cpp > --- YASim/Gear.cpp 24 Nov 2005 17:35:42 -0000 1.7 > +++ YASim/Gear.cpp 21 Dec 2006 01:04:33 -0000 > @@ -4,6 +4,9 @@ > > #include "Gear.hpp" > namespace yasim { > +static const float YASIM_PI = 3.14159265358979323846; > +static const float maxGroundBumpAmplitude=0.5; > + //Amplitude can be positive and negative > > Gear::Gear() > { > @@ -19,6 +22,19 @@ Gear::Gear() > _extension = 1; > _castering = false; > _frac = 0; > + _ground_type = 0; > + _ground_frictionFactor = 1; > + _ground_rollingFriction = 0.02; > + _ground_loadCapacity = 1e30; > + _ground_loadResistance = 1e30; > + _ground_isSolid=1; > + _ground_bumpiness = 0; > + _onlyOnWater=0; > + _notOnWater=1; > + _global_x=0.0; > + _global_y=0.0; > + _inverseSpeedSpringIsDoubled=0; > + _reduceFrictionBySpeed=0; > > for(i=0; i<3; i++) > _global_ground[i] = _global_vel[i] = 0; > @@ -78,11 +94,46 @@ void Gear::setCastering(bool c) > _castering = c; > } > > -void Gear::setGlobalGround(double *global_ground, float* global_vel) > +void Gear::setOnlyOnWater(bool c) > +{ > + _onlyOnWater = c; > +} > + > +void Gear::setNotOnWater(bool c) > +{ > + _notOnWater = c; > +} > + > +void Gear::setInverseSpeedSpringIsDoubled(float s) > +{ > + _inverseSpeedSpringIsDoubled=s; > +} > + > +void Gear::setReduceFrictionBySpeed(float s) > +{ > + _reduceFrictionBySpeed=s; > +} > + > +void Gear::setGlobalGround(double *global_ground, float* global_vel, > + double globalX, double globalY, > + int type, double frictionFactor, > + double rollingFriction, double loadCapacity, > + double loadResistance, double bumpiness, > + bool isSolid) > { > int i; > for(i=0; i<4; i++) _global_ground[i] = global_ground[i]; > for(i=0; i<3; i++) _global_vel[i] = global_vel[i]; > + _ground_type = type; > + _ground_frictionFactor=frictionFactor; > + _ground_rollingFriction=rollingFriction; > + _ground_loadCapacity=loadCapacity; > + _ground_loadResistance=loadResistance; > + _ground_bumpiness=bumpiness; > + _ground_isSolid=isSolid; > + _global_x=globalX; > + _global_y=globalY; > + > } > > void Gear::getPosition(float* out) > @@ -159,6 +210,26 @@ bool Gear::getCastering() > return _castering; > } > > +float Gear::getBumbAltitude() > +{ > + if (_ground_bumpiness<0.001) return 0.0; > + double x = _global_x*10; > + double y = _global_y*10; > + x-=Math::floor(x); > + y-=Math::floor(y); > + x*=2*YASIM_PI; > + y*=2*YASIM_PI; > + //now x and y are in the range of 0..2pi > + //we need a function, that is periodically on 2pi and gives some > + //height. This is not very fast, but for a beginning. > + //maybe this should be done by interpolating between some precalculated > + //values > + float h= Math::sin(x)+Math::sin(7*x)+Math::sin(8*x)+Math::sin(13*x); > + h+= Math::sin(2*y)+Math::sin(5*y)+Math::sin(9*y*x)+Math::sin(17*y); > + > + return h *(1/8.)*_ground_bumpiness*maxGroundBumpAmplitude; > +} > + > void Gear::calcForce(RigidBody* body, State *s, float* v, float* rot) > { > // Init the return values > @@ -169,6 +240,15 @@ void Gear::calcForce(RigidBody* body, St > if(_extension < 1) > return; > > + if ((_onlyOnWater&&_ground_isSolid)||(_notOnWater&&!_ground_isSolid)) { > + _wow = 0; > + _frac = 0; > + _compressDist = 0; > + _rollSpeed = 0; > + _casterAngle = 0; > + return; > + } > + > // The ground plane transformed to the local frame. > float ground[4]; > s->planeGlobalToLocal(_global_ground, ground); > @@ -180,6 +260,12 @@ void Gear::calcForce(RigidBody* body, St > // First off, make sure that the gear "tip" is below the ground. > // If it's not, there's no force. > float a = ground[3] - Math::dot3(_pos, ground); > + float BumbAltitude=0; > + if (a<maxGroundBumpAmplitude) > + { > + BumbAltitude=getBumbAltitude(); > + a+=BumbAltitude; > + } > _compressDist = -a; > if(a > 0) { > _wow = 0; > @@ -196,7 +282,7 @@ void Gear::calcForce(RigidBody* body, St > // above ground is negative. > float tmp[3]; > Math::add3(_cmpr, _pos, tmp); > - float b = ground[3] - Math::dot3(tmp, ground); > + float b = ground[3] - Math::dot3(tmp, ground)+BumbAltitude; > > // Calculate the point of ground _contact. > _frac = a/(a-b); > @@ -219,7 +305,11 @@ void Gear::calcForce(RigidBody* body, St > // compression. (note the clamping of _frac to 1): > _frac = (_frac > 1) ? 1 : _frac; > float fmag = _frac*clen*_spring; > - > + float inversespeed_multiplied_by_speed=0; > + if (_inverseSpeedSpringIsDoubled>0.0000001) { > + > inversespeed_multiplied_by_speed=Math::mag3(cv)*_inverseSpeedSpringIsDoubled; > + fmag*=1+inversespeed_multiplied_by_speed; > + } > // Then the damping. Use the only the velocity into the ground > // (projection along "ground") projected along the compression > // axis. So Vdamp = ground*(ground dot cv) dot cmpr > @@ -285,10 +375,18 @@ void Gear::calcForce(RigidBody* body, St > _casterAngle = _rot; > } > > - float fsteer = _brake * calcFriction(wgt, vsteer); > - float fskid = calcFriction(wgt, vskid); > + float fsteer = (_brake * _ground_frictionFactor > + +(1-_brake)*_ground_rollingFriction > + )*calcFriction(wgt, vsteer); > + float fskid = calcFriction(wgt, vskid)*_ground_frictionFactor; > if(vsteer > 0) fsteer = -fsteer; > if(vskid > 0) fskid = -fskid; > + > + //reduce friction if wanted by _reduceFrictionBySpeed > + float factor = 1-inversespeed_multiplied_by_speed*_reduceFrictionBySpeed; > + factor=Math::clamp(factor,0,1); > + fsteer*=factor; > + fskid*=factor; > > // Phoo! All done. Add it up and get out of here. > Math::mul3(fsteer, steer, tmp); > Index: YASim/Gear.hpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Gear.hpp,v > retrieving revision 1.5 > diff -u -p -r1.5 Gear.hpp > --- YASim/Gear.hpp 24 Nov 2005 17:35:42 -0000 1.5 > +++ YASim/Gear.hpp 21 Dec 2006 01:04:33 -0000 > @@ -39,8 +39,15 @@ public: > void setRotation(float rotation); > void setExtension(float extension); > void setCastering(bool castering); > - void setGlobalGround(double* global_ground, float* global_vel); > - > + void setOnlyOnWater(bool c); > + void setNotOnWater(bool c); > + void setInverseSpeedSpringIsDoubled(float s); > + void setReduceFrictionBySpeed(float s); > + void setGlobalGround(double* global_ground, float* global_vel, > + double globalX, double globalY, > + int type, double frictionFactor,double rollingFriction, > + double loadCapacity, double loadResistance, double bumpiness, > + bool isSolid); > void getPosition(float* out); > void getCompression(float* out); > void getGlobalGround(double* global_ground); > @@ -54,6 +61,8 @@ public: > bool getCastering(); > float getCasterAngle() { return _casterAngle; } > float getRollSpeed() { return _rollSpeed; } > + float getBumbAltitude(); > + > > // Takes a velocity of the aircraft relative to ground, a rotation > // vector, and a ground plane (all specified in local coordinates) > @@ -90,6 +99,19 @@ private: > float _global_vel[3]; > float _casterAngle; > float _rollSpeed; > + int _ground_type; > + double _ground_frictionFactor; > + double _ground_rollingFriction; > + double _ground_loadCapacity; > + double _ground_loadResistance; > + double _ground_bumpiness; > + bool _ground_isSolid; > + bool _onlyOnWater; > + bool _notOnWater; > + float _inverseSpeedSpringIsDoubled; > + float _reduceFrictionBySpeed; > + double _global_x; > + double _global_y; > }; > > }; // namespace yasim > Index: YASim/Ground.cpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Ground.cpp,v > retrieving revision 1.1 > diff -u -p -r1.1 Ground.cpp > --- YASim/Ground.cpp 17 Feb 2005 10:37:26 -0000 1.1 > +++ YASim/Ground.cpp 21 Dec 2006 01:04:34 -0000 > @@ -28,6 +28,19 @@ void Ground::getGroundPlane(const double > vel[2] = 0.0; > } > > +void Ground::getGroundPlane(const double pos[3], > + double plane[4], float vel[3], > + int *type, > + double *frictionFactor, > + double *rollingFriction, > + double *loadCapacity, > + double *loadResistance, > + double *bumpiness, > + bool *isSolid) > +{ > + getGroundPlane(pos,plane,vel); > +} > + > bool Ground::caughtWire(const double pos[4][3]) > { > return false; > Index: YASim/Ground.hpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Ground.hpp,v > retrieving revision 1.1 > diff -u -p -r1.1 Ground.hpp > --- YASim/Ground.hpp 17 Feb 2005 10:37:26 -0000 1.1 > +++ YASim/Ground.hpp 21 Dec 2006 01:04:34 -0000 > @@ -11,6 +11,16 @@ public: > virtual void getGroundPlane(const double pos[3], > double plane[4], float vel[3]); > > + virtual void getGroundPlane(const double pos[3], > + double plane[4], float vel[3], > + int *type, > + double *frictionFactor, > + double *rollingFriction, > + double *loadCapacity, > + double *loadResistance, > + double *bumpiness, > + bool *isSolid); > + > virtual bool caughtWire(const double pos[4][3]); > > virtual bool getWire(double end[2][3], float vel[2][3]); > Index: YASim/Model.cpp > =================================================================== > RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Model.cpp,v > retrieving revision 1.13 > diff -u -p -r1.13 Model.cpp > --- YASim/Model.cpp 14 Sep 2006 18:18:33 -0000 1.13 > +++ YASim/Model.cpp 21 Dec 2006 01:04:36 -0000 > @@ -307,8 +307,26 @@ void Model::updateGround(State* s) > // Ask for the ground plane in the global coordinate system > double global_ground[4]; > float global_vel[3]; > - _ground_cb->getGroundPlane(pt, global_ground, global_vel); > - g->setGlobalGround(global_ground, global_vel); > + int type; > + double frictionFactor, rollingFriction, loadCapacity, > + loadResistance, bumpiness; > + bool isSolid; > + //_ground_cb->getGroundPlane(pt, global_ground, global_vel); > + _ground_cb->getGroundPlane(pt, global_ground, global_vel, > + &type,&frictionFactor, &rollingFriction, > + &loadCapacity, > &loadResistance,&bumpiness,&isSolid); > + static int h=0; > + /* > + if (h++>100) > + { > + cout<<"t:"<<type<<"fF:"<<frictionFactor<<"rF:"<<rollingFriction > + <<"lC:"<<loadCapacity<<"lR"<<loadResistance<<"b:"<<bumpiness<<" > \r"; > + h=0; > + } > + */ > + g->setGlobalGround(global_ground, global_vel, pt[0], pt[1],type, > + frictionFactor, rollingFriction, loadCapacity, loadResistance, > + bumpiness,isSolid); > } > for(i=0; i<_rotorgear.getRotors()->size(); i++) { > Rotor* r = (Rotor*)_rotorgear.getRotors()->get(i); > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys - and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
