#include <simgear/debug/logstream.hxx>
#include <simgear/timing/timestamp.hxx>
#include <simgear/scene/material/mat.hxx>
+#include <simgear/io/iochannel.hxx>
#include <Scenery/scenery.hxx>
#include <Main/globals.hxx>
// roundoff problems when we already have nearly accurate values.
// Only the speedup thing must be still handled here
int hz = fgGetInt("/sim/model-hz");
- int multiloop = SGMiscd::roundToInt(dt*hz);
- int speedup = fgGetInt("/sim/speed-up");
- return multiloop * speedup;
+ double speedup = fgGetDouble("/sim/speed-up");
+ double loops = dt * hz * speedup + delta_loops;
+ int iloops = SGMiscd::roundToInt(loops);
+ delta_loops = loops-iloops; // delta_loops required for speed-ups < 1 (to do one iteration every n-th step)
+ return iloops;
}
inited = false;
bound = false;
- d_cg_rp_body_v = SGVec3d::zeros();
- v_dot_local_v = SGVec3d::zeros();
- v_dot_body_v = SGVec3d::zeros();
- a_cg_body_v = SGVec3d::zeros();
- a_pilot_body_v = SGVec3d::zeros();
- n_cg_body_v = SGVec3d::zeros();
- v_local_v = SGVec3d::zeros();
- v_local_rel_ground_v = SGVec3d::zeros();
- v_local_airmass_v = SGVec3d::zeros();
- v_wind_body_v = SGVec3d::zeros();
- omega_body_v = SGVec3d::zeros();
- euler_rates_v = SGVec3d::zeros();
- geocentric_rates_v = SGVec3d::zeros();
- geodetic_position_v = SGGeod::fromRadM(0, 0, 0);
- cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
- geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
- euler_angles_v = SGVec3d::zeros();
+ _state.d_cg_rp_body_v = SGVec3d::zeros();
+ _state.v_dot_local_v = SGVec3d::zeros();
+ _state.v_dot_body_v = SGVec3d::zeros();
+ _state.a_cg_body_v = SGVec3d::zeros();
+ _state.a_pilot_body_v = SGVec3d::zeros();
+ _state.n_cg_body_v = SGVec3d::zeros();
+ _state.v_local_v = SGVec3d::zeros();
+ _state.v_local_rel_ground_v = SGVec3d::zeros();
+ _state.v_local_airmass_v = SGVec3d::zeros();
+ _state.v_wind_body_v = SGVec3d::zeros();
+ _state.omega_body_v = SGVec3d::zeros();
+ _state.euler_rates_v = SGVec3d::zeros();
+ _state.geocentric_rates_v = SGVec3d::zeros();
+ _state.geodetic_position_v = SGGeod::fromRadM(0, 0, 0);
+ _state.cartesian_position_v = SGVec3d::fromGeod(_state.geodetic_position_v);
+ _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
+ _state.euler_angles_v = SGVec3d::zeros();
- nlf=0;
- v_rel_wind=v_true_kts=0;
- v_ground_speed=v_equiv_kts=0;
- v_calibrated_kts=0;
- alpha=beta=0;
- gamma_vert_rad=0;
- density=mach_number=0;
- static_pressure=total_pressure=0;
- dynamic_pressure=0;
- static_temperature=total_temperature=0;
- sea_level_radius=earth_position_angle=0;
- runway_altitude=0;
- climb_rate=0;
- altitude_agl=0;
- track=0;
+ _state.nlf=0;
+ _state.v_rel_wind=_state.v_true_kts=0;
+ _state.v_ground_speed=_state.v_equiv_kts=0;
+ _state.v_calibrated_kts=0;
+ _state.alpha=_state.beta=0;
+ _state.gamma_vert_rad=0;
+ _state.density=_state.mach_number=0;
+ _state.static_pressure=_state.total_pressure=0;
+ _state.dynamic_pressure=0;
+ _state.static_temperature=_state.total_temperature=0;
+ _state.sea_level_radius=_state.earth_position_angle=0;
+ _state.runway_altitude=0;
+ _state.climb_rate=0;
+ _state.altitude_agl=0;
+ _state.track=0;
+
+ delta_loops = 0.0;
}
void
SG_LOG( SG_FLIGHT, SG_INFO, " lat = "
<< fgGetDouble("/sim/presets/latitude-deg")
<< " alt = " << get_Altitude() );
- double slr = SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v);
+ double slr = SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v);
_set_Sea_level_radius( slr * SG_METER_TO_FEET );
// Set initial Euler angles
if ( !fgHasNode("/sim/presets/speed-set") ) {
set_V_calibrated_kts(0.0);
} else {
- const string speedset = fgGetString("/sim/presets/speed-set");
+ const std::string speedset = fgGetString("/sim/presets/speed-set");
if ( speedset == "knots" || speedset == "KNOTS" ) {
set_V_calibrated_kts( fgGetDouble("/sim/presets/airspeed-kt") );
} else if ( speedset == "mach" || speedset == "MACH" ) {
SG_LOG(SG_FLIGHT, SG_ALERT, "dummy update() ... SHOULDN'T BE CALLED!");
}
+bool FGInterface::readState(SGIOChannel* io)
+{
+ FlightState buf;
+ int length = sizeof(FlightState);
+
+ if ( io->get_type() == sgFileType ) {
+ if ( io->read( (char *)(& buf), length ) == length ) {
+ SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
+ } else {
+ return false;
+ }
+ } else {
+ while ( io->read( (char *)(& buf), length ) == length ) {
+ SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
+ }
+ }
+
+ _state = buf; // copy the read state over
+ return true;
+}
+
+bool FGInterface::writeState(SGIOChannel* io)
+{
+ if (!bound || !inited) {
+ return false;
+ }
+
+ int length = sizeof(FlightState);
+ if ( ! io->write( (char *)(& _state), length ) ) {
+ SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
+ return false;
+ }
+
+ return true;
+}
void FGInterface::_updatePositionM(const SGVec3d& cartPos)
{
- TrackComputer tracker( track, geodetic_position_v );
- cartesian_position_v = cartPos;
- geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
- geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
- _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ TrackComputer tracker( _state.track, _state.geodetic_position_v );
+ _state.cartesian_position_v = cartPos;
+ _state.geodetic_position_v = SGGeod::fromCart(_state.cartesian_position_v);
+ _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
_update_ground_elev_at_pos();
}
void FGInterface::_updatePosition(const SGGeod& geod)
{
- TrackComputer tracker( track, geodetic_position_v );
- geodetic_position_v = geod;
- cartesian_position_v = SGVec3d::fromGeod(geodetic_position_v);
- geocentric_position_v = SGGeoc::fromCart(cartesian_position_v);
+ TrackComputer tracker( _state.track, _state.geodetic_position_v );
+ _state.geodetic_position_v = geod;
+ _state.cartesian_position_v = SGVec3d::fromGeod(_state.geodetic_position_v);
+ _state.geocentric_position_v = SGGeoc::fromCart(_state.cartesian_position_v);
- _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
_update_ground_elev_at_pos();
}
void FGInterface::_updatePosition(const SGGeoc& geoc)
{
- TrackComputer tracker( track, geodetic_position_v );
- geocentric_position_v = geoc;
- cartesian_position_v = SGVec3d::fromGeoc(geocentric_position_v);
- geodetic_position_v = SGGeod::fromCart(cartesian_position_v);
+ TrackComputer tracker( _state.track, _state.geodetic_position_v );
+ _state.geocentric_position_v = geoc;
+ _state.cartesian_position_v = SGVec3d::fromGeoc(_state.geocentric_position_v);
+ _state.geodetic_position_v = SGGeod::fromCart(_state.cartesian_position_v);
- _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(geodetic_position_v)*SG_METER_TO_FEET );
+ _set_Sea_level_radius( SGGeodesy::SGGeodToSeaLevelRadius(_state.geodetic_position_v)*SG_METER_TO_FEET );
_update_ground_elev_at_pos();
}
}
void FGInterface::_update_ground_elev_at_pos( void ) {
- double groundlevel_m = get_groundlevel_m(geodetic_position_v);
+ double groundlevel_m = get_groundlevel_m(_state.geodetic_position_v);
_set_Runway_altitude( groundlevel_m * SG_METER_TO_FEET );
}
// Positions
void FGInterface::set_Latitude(double lat) {
- geodetic_position_v.setLatitudeRad(lat);
+ _state.geodetic_position_v.setLatitudeRad(lat);
}
void FGInterface::set_Longitude(double lon) {
- geodetic_position_v.setLongitudeRad(lon);
+ _state.geodetic_position_v.setLongitudeRad(lon);
}
void FGInterface::set_Altitude(double alt) {
- geodetic_position_v.setElevationFt(alt);
+ _state.geodetic_position_v.setElevationFt(alt);
}
void FGInterface::set_AltitudeAGL(double altagl) {
- altitude_agl=altagl;
+ _state.altitude_agl=altagl;
}
// Velocities
void FGInterface::set_V_calibrated_kts(double vc) {
- v_calibrated_kts = vc;
+ _state.v_calibrated_kts = vc;
}
void FGInterface::set_Mach_number(double mach) {
- mach_number = mach;
+ _state.mach_number = mach;
}
void FGInterface::set_Velocities_Local( double north,
double east,
double down ){
- v_local_v[0] = north;
- v_local_v[1] = east;
- v_local_v[2] = down;
+ _state.v_local_v[0] = north;
+ _state.v_local_v[1] = east;
+ _state.v_local_v[2] = down;
}
void FGInterface::set_Velocities_Wind_Body( double u,
double v,
double w){
- v_wind_body_v[0] = u;
- v_wind_body_v[1] = v;
- v_wind_body_v[2] = w;
+ _state.v_wind_body_v[0] = u;
+ _state.v_wind_body_v[1] = v;
+ _state.v_wind_body_v[2] = w;
}
// Euler angles
void FGInterface::set_Euler_Angles( double phi,
double theta,
double psi ) {
- euler_angles_v[0] = phi;
- euler_angles_v[1] = theta;
- euler_angles_v[2] = psi;
+ _state.euler_angles_v[0] = phi;
+ _state.euler_angles_v[1] = theta;
+ _state.euler_angles_v[2] = psi;
}
// Flight Path
void FGInterface::set_Climb_Rate( double roc) {
- climb_rate = roc;
+ _state.climb_rate = roc;
}
void FGInterface::set_Gamma_vert_rad( double gamma) {
- gamma_vert_rad = gamma;
+ _state.gamma_vert_rad = gamma;
}
-void FGInterface::set_Static_pressure(double p) { static_pressure = p; }
-void FGInterface::set_Static_temperature(double T) { static_temperature = T; }
-void FGInterface::set_Density(double rho) { density = rho; }
+void FGInterface::set_Static_pressure(double p) { _state.static_pressure = p; }
+void FGInterface::set_Static_temperature(double T) { _state.static_temperature = T; }
+void FGInterface::set_Density(double rho) { _state.density = rho; }
void FGInterface::set_Velocities_Local_Airmass (double wnorth,
double weast,
double wdown ) {
- v_local_airmass_v[0] = wnorth;
- v_local_airmass_v[1] = weast;
- v_local_airmass_v[2] = wdown;
+ _state.v_local_airmass_v[0] = wnorth;
+ _state.v_local_airmass_v[1] = weast;
+ _state.v_local_airmass_v[2] = wdown;
}
void FGInterface::_busdump(void)
{
- SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rp_body_v: " << d_cg_rp_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_local_v: " << v_dot_local_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_body_v: " << v_dot_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"a_cg_body_v: " << a_cg_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"a_pilot_body_v: " << a_pilot_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"n_cg_body_v: " << n_cg_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_local_v: " << v_local_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_ground_v: " << v_local_rel_ground_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_local_airmass_v: " << v_local_airmass_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"v_wind_body_v: " << v_wind_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"omega_body_v: " << omega_body_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"euler_rates_v: " << euler_rates_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_rates_v: " << geocentric_rates_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_position_v: " << geocentric_position_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"geodetic_position_v: " << geodetic_position_v);
- SG_LOG(SG_FLIGHT,SG_INFO,"euler_angles_v: " << euler_angles_v);
-
- SG_LOG(SG_FLIGHT,SG_INFO,"nlf: " << nlf );
- SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_wind: " << v_rel_wind );
- SG_LOG(SG_FLIGHT,SG_INFO,"v_true_kts: " << v_true_kts );
- SG_LOG(SG_FLIGHT,SG_INFO,"v_ground_speed: " << v_ground_speed );
- SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv_kts: " << v_equiv_kts );
- SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated_kts: " << v_calibrated_kts );
- SG_LOG(SG_FLIGHT,SG_INFO,"alpha: " << alpha );
- SG_LOG(SG_FLIGHT,SG_INFO,"beta: " << beta );
- SG_LOG(SG_FLIGHT,SG_INFO,"gamma_vert_rad: " << gamma_vert_rad );
- SG_LOG(SG_FLIGHT,SG_INFO,"density: " << density );
- SG_LOG(SG_FLIGHT,SG_INFO,"mach_number: " << mach_number );
- SG_LOG(SG_FLIGHT,SG_INFO,"static_pressure: " << static_pressure );
- SG_LOG(SG_FLIGHT,SG_INFO,"total_pressure: " << total_pressure );
- SG_LOG(SG_FLIGHT,SG_INFO,"dynamic_pressure: " << dynamic_pressure );
- SG_LOG(SG_FLIGHT,SG_INFO,"static_temperature: " << static_temperature );
- SG_LOG(SG_FLIGHT,SG_INFO,"total_temperature: " << total_temperature );
- SG_LOG(SG_FLIGHT,SG_INFO,"sea_level_radius: " << sea_level_radius );
- SG_LOG(SG_FLIGHT,SG_INFO,"earth_position_angle: " << earth_position_angle );
- SG_LOG(SG_FLIGHT,SG_INFO,"runway_altitude: " << runway_altitude );
- SG_LOG(SG_FLIGHT,SG_INFO,"climb_rate: " << climb_rate );
- SG_LOG(SG_FLIGHT,SG_INFO,"altitude_agl: " << altitude_agl );
+ SG_LOG(SG_FLIGHT,SG_INFO,"d_cg_rp_body_v: " << _state.d_cg_rp_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_local_v: " << _state.v_dot_local_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_dot_body_v: " << _state.v_dot_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"a_cg_body_v: " << _state.a_cg_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"a_pilot_body_v: " << _state.a_pilot_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"n_cg_body_v: " << _state.n_cg_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_local_v: " << _state.v_local_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_local_rel_ground_v: " << _state.v_local_rel_ground_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_local_airmass_v: " << _state.v_local_airmass_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_wind_body_v: " << _state.v_wind_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"omega_body_v: " << _state.omega_body_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"euler_rates_v: " << _state.euler_rates_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_rates_v: " << _state.geocentric_rates_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"geocentric_position_v: " << _state.geocentric_position_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"geodetic_position_v: " << _state.geodetic_position_v);
+ SG_LOG(SG_FLIGHT,SG_INFO,"euler_angles_v: " << _state.euler_angles_v);
+
+ SG_LOG(SG_FLIGHT,SG_INFO,"nlf: " << _state.nlf );
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_rel_wind: " << _state.v_rel_wind );
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_true_kts: " << _state.v_true_kts );
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_ground_speed: " << _state.v_ground_speed );
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_equiv_kts: " << _state.v_equiv_kts );
+ SG_LOG(SG_FLIGHT,SG_INFO,"v_calibrated_kts: " << _state.v_calibrated_kts );
+ SG_LOG(SG_FLIGHT,SG_INFO,"alpha: " << _state.alpha );
+ SG_LOG(SG_FLIGHT,SG_INFO,"beta: " << _state.beta );
+ SG_LOG(SG_FLIGHT,SG_INFO,"gamma_vert_rad: " << _state.gamma_vert_rad );
+ SG_LOG(SG_FLIGHT,SG_INFO,"density: " << _state.density );
+ SG_LOG(SG_FLIGHT,SG_INFO,"mach_number: " << _state.mach_number );
+ SG_LOG(SG_FLIGHT,SG_INFO,"static_pressure: " << _state.static_pressure );
+ SG_LOG(SG_FLIGHT,SG_INFO,"total_pressure: " << _state.total_pressure );
+ SG_LOG(SG_FLIGHT,SG_INFO,"dynamic_pressure: " << _state.dynamic_pressure );
+ SG_LOG(SG_FLIGHT,SG_INFO,"static_temperature: " << _state.static_temperature );
+ SG_LOG(SG_FLIGHT,SG_INFO,"total_temperature: " << _state.total_temperature );
+ SG_LOG(SG_FLIGHT,SG_INFO,"sea_level_radius: " << _state.sea_level_radius );
+ SG_LOG(SG_FLIGHT,SG_INFO,"earth_position_angle: " << _state.earth_position_angle );
+ SG_LOG(SG_FLIGHT,SG_INFO,"runway_altitude: " << _state.runway_altitude );
+ SG_LOG(SG_FLIGHT,SG_INFO,"climb_rate: " << _state.climb_rate );
+ SG_LOG(SG_FLIGHT,SG_INFO,"altitude_agl: " << _state.altitude_agl );
}
bool
FGInterface::get_agl_m(double t, const double pt[3], double max_altoff,
double contact[3], double normal[3],
double linearVel[3], double angularVel[3],
- SGMaterial const*& material, simgear::BVHNode::Id& id)
+ simgear::BVHMaterial const*& material, simgear::BVHNode::Id& id)
{
SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
SGVec3d _contact, _normal, _linearVel, _angularVel;
- const simgear::BVHMaterial* m = 0;
+ material = 0;
bool ret = ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
- _angularVel, id, m);
+ _angularVel, id, material);
// correct the linear velocity, since the line intersector delivers
// values for the start point and the get_agl function should
// traditionally deliver for the contact point
assign(normal, _normal);
assign(linearVel, _linearVel);
assign(angularVel, _angularVel);
- material = dynamic_cast<const SGMaterial*>(m);
return ret;
}
FGInterface::get_agl_ft(double t, const double pt[3], double max_altoff,
double contact[3], double normal[3],
double linearVel[3], double angularVel[3],
- SGMaterial const*& material, simgear::BVHNode::Id& id)
+ simgear::BVHMaterial const*& material, simgear::BVHNode::Id& id)
{
// Convert units and do the real work.
SGVec3d pt_m = SGVec3d(pt) - max_altoff*ground_cache.get_down();
pt_m *= SG_FEET_TO_METER;
SGVec3d _contact, _normal, _linearVel, _angularVel;
- const simgear::BVHMaterial* m = 0;
+ material = 0;
bool ret = ground_cache.get_agl(t, pt_m, _contact, _normal, _linearVel,
- _angularVel, id, m);
+ _angularVel, id, material);
// correct the linear velocity, since the line intersector delivers
// values for the start point and the get_agl function should
// traditionally deliver for the contact point
assign( normal, _normal );
assign( linearVel, SG_METER_TO_FEET*_linearVel );
assign( angularVel, _angularVel );
- material = dynamic_cast<const SGMaterial*>(m);
return ret;
}
FGInterface::get_nearest_m(double t, const double pt[3], double maxDist,
double contact[3], double normal[3],
double linearVel[3], double angularVel[3],
- SGMaterial const*& material,
+ simgear::BVHMaterial const*& material,
simgear::BVHNode::Id& id)
{
SGVec3d _contact, _linearVel, _angularVel;
- const simgear::BVHMaterial* m = 0;
+ material = 0;
if (!ground_cache.get_nearest(t, SGVec3d(pt), maxDist, _contact, _linearVel,
- _angularVel, id, m))
+ _angularVel, id, material))
return false;
assign(contact, _contact);
assign(linearVel, _linearVel);
assign(angularVel, _angularVel);
- material = dynamic_cast<const SGMaterial*>(m);
return true;
}
FGInterface::get_nearest_ft(double t, const double pt[3], double maxDist,
double contact[3], double normal[3],
double linearVel[3], double angularVel[3],
- SGMaterial const*& material,
+ simgear::BVHMaterial const*& material,
simgear::BVHNode::Id& id)
{
SGVec3d _contact, _linearVel, _angularVel;
- const simgear::BVHMaterial* m = 0;
+ material = 0;
if (!ground_cache.get_nearest(t, SG_FEET_TO_METER*SGVec3d(pt),
SG_FEET_TO_METER*maxDist, _contact, _linearVel,
- _angularVel, id, m))
+ _angularVel, id, material))
return false;
assign(contact, SG_METER_TO_FEET*_contact);
assign(linearVel, SG_METER_TO_FEET*_linearVel);
assign(angularVel, _angularVel);
- material = dynamic_cast<const SGMaterial*>(m);
return true;
}
}
double contact[3], normal[3], vel[3], angvel[3];
- const SGMaterial* material;
+ const simgear::BVHMaterial* material;
simgear::BVHNode::Id id;
// Ignore the return value here, since it just tells us if
// the returns stem from the groundcache or from the coarse