src/AIModel/AIBallistic.cxx

   1 // FGAIBallistic - FGAIBase-derived class creates a ballistic object
   2 //
   3 // Written by David Culp, started November 2003.
   4 // - davidculp2@comcast.net
   5 //
   6 // With major additions by Mathias Froehlich & Vivian Meazza 2004-2008
   7 //
   8 // This program is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU General Public License as
  10 // published by the Free Software Foundation; either version 2 of the
  11 // License, or (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful, but
  14 // WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  21
  22 #ifdef HAVE_CONFIG_H
  23 #  include <config.h>
  24 #endif
  25
  26 #include <simgear/math/point3d.hxx>
  27 #include <simgear/math/sg_random.h>
  28 #include <simgear/math/sg_geodesy.hxx>
  29
  30 #include <Scenery/scenery.hxx>
  31
  32 #include "AIBallistic.hxx"
  33
  34 const double FGAIBallistic::slugs_to_kgs = 14.5939029372;
  35 const double FGAIBallistic::slugs_to_lbs = 32.1740485564;
  36
  37 FGAIBallistic::FGAIBallistic() :
  38     FGAIBase(otBallistic),
  39     _elevation(0),
  40     _aero_stabilised(false),
  41     _drag_area(0.007),
  42     _life_timer(0.0),
  43 _gravity(32.1740485564),
  44     _buoyancy(0),
  45     _random(false),
  46     _ht_agl_ft(0),
  47     _load_resistance(0),
  48     _solid(false),
  49     _report_collision(false),
  50     _report_impact(false),
  51 _wind(true),
  52     _impact_report_node(fgGetNode("/ai/models/model-impact", true)),
  53     _external_force(false)
  54
  55 {
  56     no_roll = false;
  57 }
  58
  59 FGAIBallistic::~FGAIBallistic() {
  60 }
  61
  62 void FGAIBallistic::readFromScenario(SGPropertyNode* scFileNode) {
  63     if (!scFileNode){
  64         return;
  65     }
  66
  67     FGAIBase::readFromScenario(scFileNode);
  68
  69     //setPath(scFileNode->getStringValue("model", "Models/Geometry/rocket.ac"));
  70     setAzimuth(scFileNode->getDoubleValue("azimuth", 0.0));
  71     setElevation(scFileNode->getDoubleValue("elevation", 0));
  72     setDragArea(scFileNode->getDoubleValue("eda", 0.007));
  73     setLife(scFileNode->getDoubleValue("life", 900.0));
  74     setBuoyancy(scFileNode->getDoubleValue("buoyancy", 0));
  75     setWind_from_east(scFileNode->getDoubleValue("wind_from_east", 0));
  76     setWind_from_north(scFileNode->getDoubleValue("wind_from_north", 0));
  77     setWind(scFileNode->getBoolValue("wind", false));
  78     setRoll(scFileNode->getDoubleValue("roll", 0.0));
  79     setCd(scFileNode->getDoubleValue("cd", 0.029));
  80     setMass(scFileNode->getDoubleValue("mass", 0.007));
  81     setStabilisation(scFileNode->getBoolValue("aero_stabilized", false));
  82     setNoRoll(scFileNode->getBoolValue("no-roll", false));
  83     setRandom(scFileNode->getBoolValue("random", false));
  84     setImpact(scFileNode->getBoolValue("impact", false));
  85     setImpactReportNode(scFileNode->getStringValue("impact-reports"));
  86     setName(scFileNode->getStringValue("name", "Rocket"));
  87     setFuseRange(scFileNode->getDoubleValue("fuse-range", 0.0));
  88     setSMPath(scFileNode->getStringValue("submodel-path", ""));
  89     setSubID(scFileNode->getIntValue("SubID", 0));
  90     setExternalForce(scFileNode->getBoolValue("external-force", false));
  91     setForcePath(scFileNode->getStringValue("force-path", ""));
  92     setForceStabilisation(scFileNode->getBoolValue("force_stabilized", false));
  93     setXOffset(scFileNode->getDoubleValue("x-offset", 0.0));
  94     setYOffset(scFileNode->getDoubleValue("y-offset", 0.0));
  95     setZOffset(scFileNode->getDoubleValue("z-offset", 0.0));
  96 }
  97
  98 bool FGAIBallistic::init(bool search_in_AI_path) {
  99     FGAIBase::init(search_in_AI_path);
 100
 101     props->setStringValue("material/name", "");
 102     props->setStringValue("name", _name.c_str());
 103     props->setStringValue("submodels/path", _submodel.c_str());
 104
 105     // start with high value so that animations don't trigger yet
 106     _ht_agl_ft = 1e10;
 107     hdg = _azimuth;
 108     pitch = _elevation;
 109     roll = _rotation;
 110
 111     Transform();
 112
 113     return true;
 114 }
 115
 116 void FGAIBallistic::bind() {
 117     //    FGAIBase::bind();
 118     props->tie("sim/time/elapsed-sec",
 119         SGRawValueMethods<FGAIBallistic,double>(*this,
 120         &FGAIBallistic::_getTime));
 121     props->tie("material/load-resistance",
 122                 SGRawValuePointer<double>(&_load_resistance));
 123     props->tie("material/solid",
 124                 SGRawValuePointer<bool>(&_solid));
 125     props->tie("altitude-agl-ft",
 126                 SGRawValuePointer<double>(&_ht_agl_ft));
 127 }
 128
 129 void FGAIBallistic::unbind() {
 130     //    FGAIBase::unbind();
 131     props->untie("sim/time/elapsed-sec");
 132     props->untie("material/load-resistance");
 133     props->untie("material/solid");
 134     props->untie("altitude-agl-ft");
 135 }
 136
 137 void FGAIBallistic::update(double dt) {
 138     FGAIBase::update(dt);
 139     Run(dt);
 140     Transform();
 141 }
 142
 143 void FGAIBallistic::setAzimuth(double az) {
 144     hdg = _azimuth = az;
 145 }
 146
 147 void FGAIBallistic::setElevation(double el) {
 148     pitch = _elevation = el;
 149 }
 150
 151 void FGAIBallistic::setRoll(double rl) {
 152     _rotation = rl;
 153 }
 154
 155 void FGAIBallistic::setStabilisation(bool val) {
 156     _aero_stabilised = val;
 157 }
 158
 159 void FGAIBallistic::setForceStabilisation(bool val) {
 160     _force_stabilised = val;
 161 }
 162
 163 void FGAIBallistic::setNoRoll(bool nr) {
 164     no_roll = nr;
 165 }
 166
 167 void FGAIBallistic::setDragArea(double a) {
 168     _drag_area = a;
 169 }
 170
 171 void FGAIBallistic::setLife(double seconds) {
 172     life = seconds;
 173 }
 174
 175 void FGAIBallistic::setBuoyancy(double fpss) {
 176     _buoyancy = fpss;
 177 }
 178
 179 void FGAIBallistic::setWind_from_east(double fps) {
 180     _wind_from_east = fps;
 181 }
 182
 183 void FGAIBallistic::setWind_from_north(double fps) {
 184     _wind_from_north = fps;
 185 }
 186
 187 void FGAIBallistic::setWind(bool val) {
 188     _wind = val;
 189 }
 190
 191 void FGAIBallistic::setCd(double c) {
 192     _Cd = c;
 193 }
 194
 195 void FGAIBallistic::setMass(double m) {
 196     _mass = m;
 197 }
 198
 199 void FGAIBallistic::setRandom(bool r) {
 200     _random = r;
 201 }
 202
 203 void FGAIBallistic::setImpact(bool i) {
 204     _report_impact = i;
 205 }
 206
 207 void FGAIBallistic::setCollision(bool c) {
 208     _report_collision = c;
 209 }
 210
 211 void FGAIBallistic::setExternalForce(bool f) {
 212     _external_force = f;
 213 }
 214
 215 void FGAIBallistic::setImpactReportNode(const string& path) {
 216
 217     if (!path.empty())
 218         _impact_report_node = fgGetNode(path.c_str(), true);
 219 }
 220
 221 void FGAIBallistic::setName(const string& n) {
 222     _name = n;
 223 }
 224
 225 void FGAIBallistic::setSMPath(const string& s) {
 226     _submodel = s;
 227 }
 228
 229 void FGAIBallistic::setFuseRange(double f) {
 230     _fuse_range = f;
 231 }
 232
 233 void FGAIBallistic::setXOffset(double x) {
 234     _x_offset = x;
 235 }
 236
 237 void FGAIBallistic::setYOffset(double y) {
 238     _y_offset = y;
 239 }
 240
 241 void FGAIBallistic::setZOffset(double z) {
 242     _z_offset = z;
 243 }
 244
 245 void FGAIBallistic::setSubID(int i) {
 246     _subID = i;
 247     //cout << "sub id " << _subID << " name " << _name << endl;
 248 }
 249
 250 void FGAIBallistic::setSubmodel(const string& s) {
 251     _submodel = s;
 252 }
 253
 254 void FGAIBallistic::setForcePath(const string& p) {
 255     _force_path = p;
 256     if (!_force_path.empty()) {
 257         SGPropertyNode *fnode = fgGetNode(_force_path.c_str(), 0, true );
 258         _force_node = fnode->getChild("force-lb", 0, true);
 259         _force_azimuth_node = fnode->getChild("force-azimuth-deg", 0, true);
 260         _force_elevation_node = fnode->getChild("force-elevation-deg", 0, true);
 261     }
 262 }
 263
 264 bool FGAIBallistic::getHtAGL(){
 265
 266     if (globals->get_scenery()->get_elevation_m(pos.getLatitudeDeg(), pos.getLongitudeDeg(),
 267         10000.0, _elevation_m, &_material)){
 268             _ht_agl_ft = pos.getElevationFt() - _elevation_m * SG_METER_TO_FEET;
 269             if (_material) {
 270                 const vector<string>& names = _material->get_names();
 271
 272                 _solid = _material->get_solid();
 273                 _load_resistance = _material->get_load_resistance();
 274                 _frictionFactor =_material->get_friction_factor();
 275                 if (!names.empty())
 276                     props->setStringValue("material/name", names[0].c_str());
 277                 else
 278                     props->setStringValue("material/name", "");
 279                 /*cout << "material " << mat_name
 280                 << " solid " << _solid
 281                 << " load " << _load_resistance
 282                 << " frictionFactor " << frictionFactor
 283                 << endl;*/
 284             }
 285             return true;
 286     } else {
 287         return false;
 288     }
 289
 290 }
 291
 292 double FGAIBallistic::getRecip(double az){
 293     // calculate the reciprocal of the input azimuth
 294     if(az - 180 < 0){
 295         return az + 180;
 296     } else {
 297         return az - 180;
 298     }
 299 }
 300
 301 void FGAIBallistic::setPitch(double e, double dt, double coeff){
 302     double c = dt / (coeff + dt);
 303     pitch = (e * c) + (pitch * (1 - c));
 304 }
 305
 306 void FGAIBallistic::setHdg(double dt, double coeff){
 307     double recip = getRecip(hdg);
 308     double c = dt / (coeff + dt);
 309     //we need to ensure that we turn the short way to the new hdg
 310     if (_azimuth < recip && _azimuth < hdg && hdg > 180) {
 311         hdg = ((_azimuth + 360) * c) + (hdg * (1 - c));
 312     } else if (_azimuth > recip && _azimuth > hdg && hdg <= 180){
 313         hdg = ((_azimuth - 360) * c) + (hdg * (1 - c));
 314     } else {
 315         hdg = (_azimuth * c) + (hdg * (1 - c));
 316     }
 317 }
 318
 319 void FGAIBallistic::Run(double dt) {
 320     _life_timer += dt;
 321
 322     if (_life_timer > life && life != -1)
 323         setDie(true);
 324
 325     //randomise Cd by +- 5%
 326     if (_random)
 327         _Cd = _Cd * 0.95 + (0.05 * sg_random());
 328
 329     // Adjust Cd by Mach number. The equations are based on curves
 330     // for a conventional shell/bullet (no boat-tail).
 331     double Cdm;
 332
 333     if (Mach < 0.7)
 334         Cdm = 0.0125 * Mach + _Cd;
 335     else if (Mach < 1.2 )
 336         Cdm = 0.3742 * pow(Mach, 2) - 0.252 * Mach + 0.0021 + _Cd;
 337     else
 338         Cdm = 0.2965 * pow(Mach, -1.1506) + _Cd;
 339
 340     //cout << " Mach , " << Mach << " , Cdm , " << Cdm << " ballistic speed kts //"<< speed <<  endl;
 341
 342     // drag = Cd * 0.5 * rho * speed * speed * drag_area;
 343     // rho is adjusted for altitude in void FGAIBase::update,
 344     // using Standard Atmosphere (sealevel temperature 15C)
 345     // acceleration = drag/mass;
 346     // adjust speed by drag
 347     speed -= (Cdm * 0.5 * rho * speed * speed * _drag_area/_mass) * dt;
 348
 349     // don't let speed become negative
 350     if ( speed < 0.0 )
 351         speed = 0.0;
 352
 353     double speed_fps = speed * SG_KT_TO_FPS;
 354     double hs;
 355
 356     // calculate vertical and horizontal speed components
 357     if (speed == 0.0) {
 358         hs = vs = 0.0;
 359     } else {
 360         vs = sin( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
 361         hs = cos( _elevation * SG_DEGREES_TO_RADIANS ) * speed_fps;
 362     }
 363
 364     //resolve horizontal speed into north and east components:
 365     double speed_north_fps = cos(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
 366     double speed_east_fps = sin(_azimuth / SG_RADIANS_TO_DEGREES) * hs;
 367
 368     // convert horizontal speed (fps) to degrees per second
 369     double speed_north_deg_sec = speed_north_fps / ft_per_deg_lat;
 370     double speed_east_deg_sec  = speed_east_fps / ft_per_deg_lon;
 371
 372     // if wind not required, set to zero
 373     if (!_wind) {
 374         _wind_from_north = 0;
 375         _wind_from_east = 0;
 376     } else {
 377         _wind_from_north = manager->get_wind_from_north();
 378         _wind_from_east = manager->get_wind_from_east();
 379     }
 380
 381     //calculate velocity due to external force
 382     double force_speed_north_deg_sec = 0;
 383     double force_speed_east_deg_sec = 0;
 384     double vs_force_fps = 0;
 385     double hs_force_fps = 0;
 386     double v_force_acc_fpss = 0;
 387     double force_speed_north_fps = 0;
 388     double force_speed_east_fps = 0;
 389     double h_force_lbs = 0;
 390     double normal_force_lbs = 0;
 391     double normal_force_fpss = 0;
 392     double static_friction_force_lbs = 0;
 393     double dynamic_friction_force_lbs = 0;
 394     double friction_force_speed_north_fps = 0;
 395     double friction_force_speed_east_fps = 0;
 396     double friction_force_speed_north_deg_sec = 0;
 397     double friction_force_speed_east_deg_sec = 0;
 398     double force_elevation_deg = 0;
 399
 400     if (_external_force) {
 401         SGPropertyNode *n = fgGetNode(_force_path.c_str(), true);
 402         double force_lbs            = n->getChild("force-lb", 0, true)->getDoubleValue();
 403         force_elevation_deg         = n->getChild("force-elevation-deg", 0, true)->getDoubleValue();
 404         double force_azimuth_deg    = n->getChild("force-azimuth-deg", 0, true)->getDoubleValue();
 405
 406         //resolve force into vertical and horizontal components:
 407         double v_force_lbs = force_lbs * sin( force_elevation_deg * SG_DEGREES_TO_RADIANS );
 408         h_force_lbs = force_lbs * cos( force_elevation_deg * SG_DEGREES_TO_RADIANS );
 409
 410         //ground interaction
 411
 412         if (getHtAGL()){
 413             double deadzone = 0.1;
 414
 415             if ( _ht_agl_ft <= (0 + _z_offset + deadzone) && _solid){
 416                 normal_force_lbs = (_mass * slugs_to_lbs) - v_force_lbs;
 417                 pos.setElevationFt((_elevation_m * SG_METER_TO_FEET) + _z_offset);
 418                 vs = 0;
 419
 420                 // calculate friction
 421                 // we assume a static Coefficient of Friction (mu) of 0.62 (wood on concrete)
 422                 double mu = 0.62;
 423
 424                 static_friction_force_lbs = mu * normal_force_lbs * _frictionFactor;
 425
 426                 //adjust horizontal force
 427                 if (h_force_lbs <= static_friction_force_lbs && hs <= 0.1)
 428                     h_force_lbs = hs = 0;
 429                 else
 430                     dynamic_friction_force_lbs = (static_friction_force_lbs * 0.75);
 431
 432                 //ignore wind when on the ground for now
 433                 //TODO fix this
 434                 _wind_from_north = 0;
 435                 _wind_from_east = 0;
 436
 437             }
 438
 439         }
 440
 441         //acceleration = (force(lbsf)/mass(slugs))
 442         v_force_acc_fpss = v_force_lbs/_mass;
 443         normal_force_fpss = normal_force_lbs/_mass;
 444         double h_force_acc_fpss = h_force_lbs/_mass;
 445         double dynamic_friction_acc_fpss = dynamic_friction_force_lbs/_mass;
 446
 447         // velocity = acceleration * dt
 448         hs_force_fps = h_force_acc_fpss * dt;
 449         double friction_force_fps = dynamic_friction_acc_fpss * dt;
 450
 451         //resolve horizontal speeds into north and east components:
 452         force_speed_north_fps   = cos(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
 453         force_speed_east_fps    = sin(force_azimuth_deg * SG_DEGREES_TO_RADIANS) * hs_force_fps;
 454
 455         double friction_force_speed_north_fps = cos(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
 456         double friction_force_speed_east_fps  = sin(getRecip(hdg) * SG_DEGREES_TO_RADIANS) * friction_force_fps;
 457
 458         // convert horizontal speed (fps) to degrees per second
 459         force_speed_north_deg_sec = force_speed_north_fps / ft_per_deg_lat;
 460         force_speed_east_deg_sec  = force_speed_east_fps / ft_per_deg_lon;
 461
 462         friction_force_speed_north_deg_sec = friction_force_speed_north_fps / ft_per_deg_lat;
 463         friction_force_speed_east_deg_sec  = friction_force_speed_east_fps / ft_per_deg_lon;
 464     }
 465
 466     // convert wind speed (fps) to degrees lat/lon per second
 467     double wind_speed_from_north_deg_sec = _wind_from_north / ft_per_deg_lat;
 468     double wind_speed_from_east_deg_sec  = _wind_from_east / ft_per_deg_lon;
 469
 470     // set new position
 471     pos.setLatitudeDeg( pos.getLatitudeDeg()
 472         + (speed_north_deg_sec - wind_speed_from_north_deg_sec
 473         + force_speed_north_deg_sec + friction_force_speed_north_deg_sec) * dt );
 474     pos.setLongitudeDeg( pos.getLongitudeDeg()
 475         + (speed_east_deg_sec - wind_speed_from_east_deg_sec
 476         + force_speed_east_deg_sec + friction_force_speed_east_deg_sec) * dt );
 477
 478     //recombine the horizontal velocity components
 479     hs = sqrt(((speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps)
 480         * (speed_north_fps + force_speed_north_fps + friction_force_speed_north_fps))
 481         + ((speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)
 482         * (speed_east_fps + force_speed_east_fps + friction_force_speed_east_fps)));
 483
 484     if (hs <= 0.00001)
 485         hs = 0;
 486
 487     // adjust vertical speed for acceleration of gravity, buoyancy, and vertical force
 488     vs -= (_gravity - _buoyancy - v_force_acc_fpss - normal_force_fpss) * dt;
 489
 490     if (vs <= 0.00001 && vs >= -0.00001)
 491         vs = 0;
 492
 493     // adjust altitude (feet) and set new elevation
 494     altitude_ft = pos.getElevationFt();
 495     altitude_ft += vs * dt;
 496     pos.setElevationFt(altitude_ft);
 497
 498     // recalculate total speed
 499     if ( vs == 0 && hs == 0)
 500         speed = 0;
 501     else
 502         speed = sqrt( vs * vs + hs * hs) / SG_KT_TO_FPS;
 503
 504     // recalculate elevation and azimuth (velocity vectors)
 505     _elevation = atan2( vs, hs ) * SG_RADIANS_TO_DEGREES;
 506     _azimuth =  atan2((speed_east_fps + force_speed_east_fps),
 507         (speed_north_fps + force_speed_north_fps)) * SG_RADIANS_TO_DEGREES;
 508
 509     // rationalise azimuth
 510     if (_azimuth < 0)
 511         _azimuth += 360;
 512
 513     if (_aero_stabilised) { // we simulate rotational moment of inertia by using a filter
 514         const double coeff = 0.9;
 515
 516         // we assume a symetrical MI about the pitch and yaw axis
 517         setPitch(_elevation, dt, coeff);
 518         setHdg(dt, coeff);
 519
 520     } else if (_force_stabilised) { // we simulate rotational moment of inertia by using a filter
 521         const double coeff = 0.9;
 522         double ratio = h_force_lbs/(_mass * slugs_to_lbs);
 523
 524         double force_pitch = acos(ratio) * SG_RADIANS_TO_DEGREES;
 525
 526         if (force_pitch <= force_elevation_deg)
 527             force_pitch = force_elevation_deg;
 528
 529         // we assume a symetrical MI about the pitch and yaw axis
 530         setPitch(force_pitch,dt, coeff);
 531         setHdg(dt, coeff);
 532     }
 533
 534     //do impacts and collisions
 535     if (_report_impact && !_impact_reported)
 536         handle_impact();
 537
 538     if (_report_collision && !_collision_reported)
 539         handle_collision();
 540
 541     // set destruction flag if altitude less than sea level -1000
 542     if (altitude_ft < -1000.0)
 543         setDie(true);
 544
 545 }  // end Run
 546
 547 double FGAIBallistic::_getTime() const {
 548     return _life_timer;
 549 }
 550
 551 void FGAIBallistic::handle_impact() {
 552
 553     // try terrain intersection
 554     if(!getHtAGL())
 555         return;
 556
 557     if (_ht_agl_ft <= 0) {
 558         SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: terrain impact");
 559         report_impact(_elevation_m);
 560         _impact_reported = true;
 561
 562         // kill the AIObject if there is no subsubmodel
 563         if (_subID == 0)
 564             setDie(true);
 565     }
 566 }
 567
 568 void FGAIBallistic::handle_collision()
 569 {
 570     const FGAIBase *object = manager->calcCollision(pos.getElevationFt(),
 571             pos.getLatitudeDeg(),pos.getLongitudeDeg(), _fuse_range);
 572
 573     if (object) {
 574         SG_LOG(SG_GENERAL, SG_DEBUG, "AIBallistic: object hit");
 575         report_impact(pos.getElevationM(), object);
 576         _collision_reported = true;
 577     }
 578 }
 579
 580 void FGAIBallistic::report_impact(double elevation, const FGAIBase *object)
 581 {
 582     _impact_lat    = pos.getLatitudeDeg();
 583     _impact_lon    = pos.getLongitudeDeg();
 584     _impact_elev   = elevation;
 585     _impact_speed  = speed * SG_KT_TO_MPS;
 586     _impact_hdg    = hdg;
 587     _impact_pitch  = pitch;
 588     _impact_roll   = roll;
 589
 590     SGPropertyNode *n = props->getNode("impact", true);
 591     if (object)
 592         n->setStringValue("type", object->getTypeString());
 593     else
 594         n->setStringValue("type", "terrain");
 595
 596     n->setDoubleValue("longitude-deg", _impact_lon);
 597     n->setDoubleValue("latitude-deg", _impact_lat);
 598     n->setDoubleValue("elevation-m", _impact_elev);
 599     n->setDoubleValue("heading-deg", _impact_hdg);
 600     n->setDoubleValue("pitch-deg", _impact_pitch);
 601     n->setDoubleValue("roll-deg", _impact_roll);
 602     n->setDoubleValue("speed-mps", _impact_speed);
 603
 604     _impact_report_node->setStringValue(props->getPath());
 605 }
 606
 607 // end AIBallistic
 608