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A couple small tweaks to the airport generator to try to eliminate

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surface artifacts.
This commit is contained in:
curt 2004-05-12 20:08:55 +00:00
parent ae939e2e44
commit 80a1b1ef23
4 changed files with 61 additions and 227 deletions
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232
src/Airports/GenAirports/apt_surface.cxx
View file

@ -40,133 +40,58 @@
SG_USING_NAMESPACE( PLib );
#if 0
// fix node elevations. Offset is added to the final elevation,
// returns average of all points.
static double calc_elevations( const string &root, const string_list elev_src,
Matrix_Point3Dd &Pts ) {
bool done = false;
int i, j;
TGArray array;
static bool limit_slope( Matrix_Point3Dd &Pts, int i1, int j1, int i2, int j2,
double average_elev_m )
{
bool slope_error = false;
// just bail if no work to do
if ( Pts.rows() == 0 || Pts.cols() == 0 ) {
return 0.0;
}
Point3Dd p1, p2;
p1 = Pts(j1,i1);
p2 = Pts(j2,i2);
// set all elevations to -9999
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
p.z() = -9999.0;
}
}
double az1, az2, dist;
double slope;
while ( !done ) {
// find first node with -9999 elevation
Point3Dd first;
bool found_one = false;
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
if ( p.z() < -9000.0 && !found_one ) {
first = p;
found_one = true;
}
}
}
geo_inverse_wgs_84( 0, p1.y(), p1.x(), p2.y(), p2.x(),
&az1, &az2, &dist );
slope = (p2.z() - p1.z()) / dist;
if ( found_one ) {
SGBucket b( first.x(), first.y() );
string base = b.gen_base_path();
if ( fabs(slope) > (slope_max + slope_eps) ) {
// need to throttle slope, let's move the point
// furthest away from average towards the center.
// try the various elevation sources
j = 0;
bool found_file = false;
while ( !found_file && j < (int)elev_src.size() ) {
string array_path = root + "/" + elev_src[j] + "/" + base
+ "/" + b.gen_index_str();
if ( array.open(array_path) ) {
found_file = true;
SG_LOG(SG_GENERAL, SG_DEBUG, "Using array_path = " << array_path);
}
j++;
}
slope_error = true;
// this will fill in a zero structure if no array data
// found/opened
array.parse( b );
SG_LOG( SG_GENERAL, SG_DEBUG, " (a) detected slope of "
<< slope << " dist = " << dist );
// this will do a hasty job of removing voids by inserting
// data from the nearest neighbor (sort of)
array.remove_voids();
double e1 = fabs(average_elev_m - p1.z());
double e2 = fabs(average_elev_m - p2.z());
// cout << " z1 = " << p1.z() << " z2 = " << p2.z() << endl;
// cout << " e1 = " << e1 << " e2 = " << e2 << endl;
// update all the non-updated elevations that are inside
// this array file
double elev;
done = true;
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
if ( p.z() < -9000.0 ) {
done = false;
elev = array.altitude_from_grid( p.x() * 3600.0,
p.y() * 3600.0 );
if ( elev > -9000 ) {
p.z() = elev;
Pts(j,i) = p;
// cout << "interpolating for " << p << endl;
// cout << p.x() << " " << p.y() << " " << p.z()
// << endl;
}
}
}
}
array.close();
if ( e1 > e2 ) {
// cout << " p1 error larger" << endl;
if ( slope > 0 ) {
p1.z() = p2.z() - (dist * slope_max);
} else {
done = true;
p1.z() = p2.z() + (dist * slope_max);
}
Pts(j1,i1) = p1;
} else {
// cout << " p2 error larger" << endl;
if ( slope > 0 ) {
p2.z() = p1.z() + (dist * slope_max);
} else {
p2.z() = p1.z() - (dist * slope_max);
}
Pts(j2,i2) = p2;
}
// cout << " z1 = " << p1.z() << " z2 = " << p2.z() << endl;
}
// do some post processing for sanity's sake
// find the average height of the queried points
double total = 0.0;
int count = 0;
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
total += p.z();
count++;
return slope_error;
}
}
double average = total / (double) count;
SG_LOG(SG_GENERAL, SG_DEBUG, "Average surface height = " << average);
// now go through the elevations and clamp them all to within
// +/-50m (164') of the average.
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
if ( p.z() < average - max_clamp ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average - max_clamp );
p.z() = average - max_clamp;
Pts(j,i) = p;
}
if ( p.z() > average + max_clamp ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average + max_clamp );
p.z() = average + max_clamp;
Pts(j,i) = p;
}
}
}
return average;
}
#endif
// Constructor, specify min and max coordinates of desired area in
@ -226,7 +151,7 @@ TGAptSurface::TGAptSurface( const string& path,
}
// Lookup the elevations of all the grid points
tgCalcElevations( path, elev_src, dPts );
tgCalcElevations( path, elev_src, dPts, 0.0 );
// Clamp the elevations against the externally provided average
// elevation.
@ -273,83 +198,14 @@ TGAptSurface::TGAptSurface( const string& path,
// Add some "slope" sanity to the resulting surface grid points
for ( int i = 0; i < Pts.cols() - 1; ++i ) {
for ( int j = 0; j < Pts.rows() - 1; ++j ) {
Point3Dd p1, p2;
double az1, az2, dist;
double slope;
p1 = Pts(j,i);
p2 = Pts(j,i+1);
geo_inverse_wgs_84( 0, p1.y(), p1.x(), p2.y(), p2.x(),
&az1, &az2, &dist );
slope = (p2.z() - p1.z()) / dist;
if ( fabs(slope) > (slope_max + slope_eps) ) {
// need to throttle slope, let's move the point
// furthest away from average towards the center.
if ( limit_slope( Pts, i, j, i+1, j, average_elev_m ) ) {
slope_error = true;
SG_LOG( SG_GENERAL, SG_DEBUG, " (a) detected slope of "
<< slope << " dist = " << dist );
double e1 = average_elev_m - p1.z();
double e2 = average_elev_m - p2.z();
// cout << " z1 = " << p1.z() << " z2 = " << p2.z() << endl;
// cout << " e1 = " << e1 << " e2 = " << e2 << endl;
if ( fabs(e1) > fabs(e2) ) {
// cout << " p1 error larger" << endl;
if ( slope > 0 ) {
p1.z() = p2.z() - (dist * slope_max);
} else {
p1.z() = p2.z() + (dist * slope_max);
}
Pts(j,i) = p1;
} else {
// cout << " p2 error larger" << endl;
if ( slope > 0 ) {
p2.z() = p1.z() + (dist * slope_max);
} else {
p2.z() = p1.z() - (dist * slope_max);
}
Pts(j,i+1) = p2;
}
// cout << " z1 = " << p1.z() << " z2 = " << p2.z() << endl;
}
p1 = Pts(j,i);
p2 = Pts(j+1,i);
geo_inverse_wgs_84( 0, p1.y(), p1.x(), p2.y(), p2.x(),
&az1, &az2, &dist );
slope = ( p2.z() - p1.z() ) / dist;
if ( fabs(slope) > (slope_max+slope_eps) ) {
// need to throttle slope, let's move the point
// furthest away from average towards the center.
if ( limit_slope( Pts, i, j, i, j+1, average_elev_m ) ) {
slope_error = true;
SG_LOG( SG_GENERAL, SG_DEBUG, " (b) detected slope of "
<< slope << " dist = " << dist );
double e1 = average_elev_m - p1.z();
double e2 = average_elev_m - p2.z();
if ( fabs(e1) > fabs(e2) ) {
if ( slope > 0 ) {
p1.z() = p2.z() - (dist * slope_max);
} else {
p1.z() = p2.z() + (dist * slope_max);
}
Pts(j,i) = p1;
} else {
if ( slope > 0 ) {
p2.z() = p1.z() + (dist * slope_max);
} else {
p2.z() = p1.z() - (dist * slope_max);
}
Pts(j+1,i) = p2;
}
if ( limit_slope( Pts, i, j, i+1, j+1, average_elev_m ) ) {
slope_error = true;
}
}
}

32
src/Airports/GenAirports/elevations.cxx
View file

@ -141,15 +141,15 @@ double tgAverageElevation( const string &root, const string_list elev_src,
// lookup node elevations for each point in the specified nurbs++
// matrix. Returns average of all points.
double tgCalcElevations( const string &root, const string_list elev_src,
Matrix_Point3Dd &Pts ) {
void tgCalcElevations( const string &root, const string_list elev_src,
Matrix_Point3Dd &Pts, const double average ) {
bool done = false;
int i, j;
TGArray array;
// just bail if no work to do
if ( Pts.rows() == 0 || Pts.cols() == 0 ) {
return 0.0;
return;
}
// set all elevations to -9999
@ -240,31 +240,9 @@ double tgCalcElevations( const string &root, const string_list elev_src,
count++;
}
}
double average = total / (double) count;
double grid_average = total / (double) count;
SG_LOG(SG_GENERAL, SG_DEBUG, "Average surface height of nurbs matrix = "
<< average);
// now go through the elevations and clamp them all to within
// +/-50m (164') of the average.
for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.rows(); ++j ) {
Point3Dd p = Pts(j,i);
if ( p.z() < average - max_clamp ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average - max_clamp );
p.z() = average - max_clamp;
Pts(j,i) = p;
}
if ( p.z() > average + max_clamp ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average + max_clamp );
p.z() = average + max_clamp;
Pts(j,i) = p;
}
}
}
return average;
<< grid_average);
}

6
src/Airports/GenAirports/elevations.hxx
View file

@ -45,9 +45,9 @@ double tgAverageElevation( const string &root, const string_list elev_src,
const point_list points_source );
// lookup node elevations for each point in the specified nurbs++
// matrix. Returns average of all points.
double tgCalcElevations( const string &root, const string_list elev_src,
Matrix_Point3Dd &Pts );
// matrix.
void tgCalcElevations( const string &root, const string_list elev_src,
Matrix_Point3Dd &Pts, double average );
// clamp all elevations to the specified range
void tgClampElevations( Matrix_Point3Dd &Pts,

2
src/Airports/GenAirports/global.hxx
View file

@ -36,7 +36,7 @@ const double coarse_grid = 700.0;
const double max_clamp = 100.0;
// maximum slope (rise/run) allowed on an airport surface
const double slope_max = 0.01;
const double slope_max = 0.009;
const double slope_eps = 0.00001;
#endif // _GEN_AIRPORT_GLOBAL_HXX