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Towards better airport surface simplification and smoothing. There were

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several bugs in the previous try.  These changes should correct them.
This commit is contained in:
curt 2004-04-06 22:50:00 +00:00
parent c75fa83c15
commit c8ded2eda1
1 changed files with 150 additions and 36 deletions
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186
src/Airports/GenAirports/apt_surface.cxx
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@ -57,9 +57,9 @@ static void calc_elevations( const string &root, const string_list elev_src,
} }
// set all elevations to -9999 // set all elevations to -9999
for ( i = 0; i < Pts.rows(); ++i ) { for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.cols(); ++j ) { for ( j = 0; j < Pts.rows(); ++j ) {
Point3Df p = Pts(i,j); Point3Df p = Pts(j,i);
p.z() = -9999.0; p.z() = -9999.0;
} }
} }
@ -68,9 +68,9 @@ static void calc_elevations( const string &root, const string_list elev_src,
// find first node with -9999 elevation // find first node with -9999 elevation
Point3Df first; Point3Df first;
bool found_one = false; bool found_one = false;
for ( i = 0; i < Pts.rows(); ++i ) { for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.cols(); ++j ) { for ( j = 0; j < Pts.rows(); ++j ) {
Point3Df p = Pts(i,j); Point3Df p = Pts(j,i);
if ( p.z() < -9000.0 && !found_one ) { if ( p.z() < -9000.0 && !found_one ) {
first = p; first = p;
found_one = true; found_one = true;
@ -107,17 +107,19 @@ static void calc_elevations( const string &root, const string_list elev_src,
// this array file // this array file
double elev; double elev;
done = true; done = true;
for ( i = 0; i < Pts.rows(); ++i ) { for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.cols(); ++j ) { for ( j = 0; j < Pts.rows(); ++j ) {
Point3Df p = Pts(i,j); Point3Df p = Pts(j,i);
if ( p.z() < -9000.0 ) { if ( p.z() < -9000.0 ) {
done = false; done = false;
elev = array.altitude_from_grid( p.x() * 3600.0, elev = array.altitude_from_grid( p.x() * 3600.0,
p.y() * 3600.0 ); p.y() * 3600.0 );
if ( elev > -9000 ) { if ( elev > -9000 ) {
p.z() = elev; p.z() = elev;
Pts(i,j) = p; Pts(j,i) = p;
// cout << "interpolating for " << p << endl; // cout << "interpolating for " << p << endl;
// cout << p.x() << " " << p.y() << " " << p.z()
// << endl;
} }
} }
} }
@ -134,9 +136,9 @@ static void calc_elevations( const string &root, const string_list elev_src,
// find the average height of the queried points // find the average height of the queried points
double total = 0.0; double total = 0.0;
int count = 0; int count = 0;
for ( i = 0; i < Pts.rows(); ++i ) { for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.cols(); ++j ) { for ( j = 0; j < Pts.rows(); ++j ) {
Point3Df p = Pts(i,j); Point3Df p = Pts(j,i);
total += p.z(); total += p.z();
count++; count++;
} }
@ -146,17 +148,21 @@ static void calc_elevations( const string &root, const string_list elev_src,
// now go through the elevations and clamp them all to within // now go through the elevations and clamp them all to within
// +/-10m (33') of the average. // +/-10m (33') of the average.
const double dz = 10.0; const double dz = 100.0;
for ( i = 0; i < Pts.rows(); ++i ) { for ( i = 0; i < Pts.cols(); ++i ) {
for ( j = 0; j < Pts.cols(); ++j ) { for ( j = 0; j < Pts.rows(); ++j ) {
Point3Df p = Pts(i,j); Point3Df p = Pts(j,i);
if ( p.z() < average - dz ) { if ( p.z() < average - dz ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average - dz );
p.z() = average - dz; p.z() = average - dz;
Pts(i,j) = p; Pts(j,i) = p;
} }
if ( p.z() > average + dz ) { if ( p.z() > average + dz ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average + dz );
p.z() = average + dz; p.z() = average + dz;
Pts(i,j) = p; Pts(j,i) = p;
} }
} }
} }
@ -201,10 +207,10 @@ TGAptSurface::TGAptSurface( const string& path,
// Build the extra res input grid // Build the extra res input grid
int mult = 10; int mult = 10;
Matrix_Point3Df dPts((xdivs+2) * mult + 1, (ydivs+2) * mult + 1); Matrix_Point3Df dPts( (ydivs+2) * mult + 1, (xdivs+2) * mult + 1 );
for ( int i = 0; i < dPts.rows(); ++i ) { for ( int i = 0; i < dPts.cols(); ++i ) {
for ( int j = 0; j < dPts.cols(); ++j ) { for ( int j = 0; j < dPts.rows(); ++j ) {
dPts(i,j) = Point3Df( min_deg.lon() + (i-mult)*(dlon/(double)mult), dPts(j,i) = Point3Df( min_deg.lon() + (i-mult)*(dlon/(double)mult),
min_deg.lat() + (j-mult)*(dlat/(double)mult), min_deg.lat() + (j-mult)*(dlat/(double)mult),
-9999 ); -9999 );
} }
@ -214,34 +220,73 @@ TGAptSurface::TGAptSurface( const string& path,
calc_elevations( path, elev_src, dPts ); calc_elevations( path, elev_src, dPts );
// Build the normal res input grid from the double res version // Build the normal res input grid from the double res version
Matrix_Point3Df Pts(xdivs + 1, ydivs + 1); Matrix_Point3Df Pts(ydivs + 1, xdivs + 1);
for ( int i = 0; i < xdivs + 1; ++i ) { for ( int i = 0; i < Pts.cols(); ++i ) {
for ( int j = 0; j < ydivs + 1; ++j ) { for ( int j = 0; j < Pts.rows(); ++j ) {
SG_LOG(SG_GENERAL, SG_DEBUG, i << "," << j); SG_LOG(SG_GENERAL, SG_DEBUG, i << "," << j);
double accum = 0.0; double accum = 0.0;
for ( int ii = 0; ii < mult; ++ii ) { for ( int ii = 0; ii < mult; ++ii ) {
for ( int jj = 0; jj < mult; ++jj ) { for ( int jj = 0; jj < mult; ++jj ) {
double value = dPts(mult*(i+1) - (mult/2) + ii, double value = dPts(mult*(j+1) - (mult/2) + jj,
mult*(j+1) - (mult/2) + jj).z(); mult*(i+1) - (mult/2) + ii).z();
SG_LOG( SG_GENERAL, SG_DEBUG, "value = " << value ); SG_LOG( SG_GENERAL, SG_DEBUG, "value = " << value );
accum += dPts(mult*(i+1) - (mult/2) + ii, accum += dPts(mult*(j+1) - (mult/2) + jj,
mult*(j+1) - (mult/2) + jj).z(); mult*(i+1) - (mult/2) + ii).z();
} }
} }
SG_LOG( SG_GENERAL, SG_DEBUG, SG_LOG( SG_GENERAL, SG_DEBUG,
" average = " << accum / (mult*mult) ); " average = " << accum / (mult*mult) );
Pts(i,j) = Point3Df( min_deg.lon() + i * dlon, Pts(j,i) = Point3Df( min_deg.lon() + i * dlon,
min_deg.lat() + j * dlat, min_deg.lat() + j * dlat,
accum / (mult*mult) ); accum / (mult*mult) );
} }
} }
#if 0
// Add some "slope" sanity to the resulting surface grid points
for ( i = 0; i < Pts.cols() - 1; ++i ) {
for ( j = 0; j < Pts.rows() - 1; ++j ) {
Point3Df p = Pts(j,i);
Point3Df p1 = Pts(j,i+1);
geo_inverse_wgs_84( 0.0,
if ( p.z() < average - dz ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average - dz );
p.z() = average - dz;
Pts(j,i) = p;
}
if ( p.z() > average + dz ) {
SG_LOG(SG_GENERAL, SG_DEBUG, " clamping " << p.z()
<< " to " << average + dz );
p.z() = average + dz;
Pts(j,i) = p;
}
}
}
#endif
// Create the nurbs surface // Create the nurbs surface
SG_LOG(SG_GENERAL, SG_DEBUG, "ready to create nurbs surface"); SG_LOG(SG_GENERAL, SG_DEBUG, "ready to create nurbs surface");
apt_surf = new PlNurbsSurfacef; apt_surf = new PlNurbsSurfacef;
apt_surf->globalInterp( Pts, 3, 3); apt_surf->globalInterp( Pts, 3, 3);
SG_LOG(SG_GENERAL, SG_DEBUG, " successful."); SG_LOG(SG_GENERAL, SG_DEBUG, " successful.");
#if 0
// For debugging only: output an array of surface points suitable
// for plotting with gnuplot. This is useful for comparing the
// approximated and smoothed surface to the original rough
// surface.
cout << "DEBUGGING TEST" << endl;
for ( int i = 0; i < (xdivs+2) * mult + 1; ++i ) {
for ( int j = 0; j < (ydivs+2) * mult + 1; ++j ) {
double x = min_deg.lon() + (i-mult)*(dlon/(double)mult);
double y = min_deg.lat() + (j-mult)*(dlat/(double)mult);
cout << x << " " << y << " " << query(x,y) << endl;
}
}
#endif
} }
@ -252,6 +297,8 @@ TGAptSurface::~TGAptSurface() {
// Query the elevation of a point, return -9999 if out of range // Query the elevation of a point, return -9999 if out of range
double TGAptSurface::query( double lon_deg, double lat_deg ) { double TGAptSurface::query( double lon_deg, double lat_deg ) {
const double eps = 0.00001;
// sanity check // sanity check
if ( lon_deg < min_deg.lon() || lon_deg > max_deg.lon() || if ( lon_deg < min_deg.lon() || lon_deg > max_deg.lon() ||
lat_deg < min_deg.lat() || lat_deg > max_deg.lat() ) lat_deg < min_deg.lat() || lat_deg > max_deg.lat() )
@ -260,12 +307,79 @@ double TGAptSurface::query( double lon_deg, double lat_deg ) {
return -9999.0; return -9999.0;
} }
// convert lon,lat to nurbs space double lat_range = max_deg.lat() - min_deg.lat();
double x = (lon_deg - min_deg.lon()) / (max_deg.lon() - min_deg.lon()); double lon_range = max_deg.lon() - min_deg.lon();
double y = (lat_deg - min_deg.lat()) / (max_deg.lat() - min_deg.lat());
Point3Df p = apt_surf->pointAt( x, y ); // convert lon,lat to nurbs space
SG_LOG(SG_GENERAL, SG_DEBUG, " querying for " << x << ", " << y << " = " << p.z()); double u = (lat_deg - min_deg.lat()) / lat_range;
double v = (lon_deg - min_deg.lon()) / lon_range;
int count = 0;
Point3Df p;
while ( count < 20 ) {
if ( u < 0.0 || u > 1.0 || v < 0.0 || v > 1.0 ) {
// oops, something goofed in the solver
}
p = apt_surf->pointAt( u, v );
// cout << " querying for " << u << ", " << v << " = " << p.z()
// << endl;
// cout << " found " << p.x() << ", " << p.y() << " = " << p.z()
// << endl;
double dx = lon_deg - p.x();
double dy = lat_deg - p.y();
// cout << " dx = " << dx << " dy = " << dy << endl;
if ( (fabs(dx) < eps) && (fabs(dy) < eps) ) {
return p.z();
} else {
u = u + (dy/lat_range);
v = v + (dx/lon_range);
if ( u < 0.0 ) { u = 0.0; }
if ( u > 1.0 ) { u = 1.0; }
if ( v < 0.0 ) { v = 0.0; }
if ( v > 1.0 ) { v = 1.0; }
}
++count;
}
// failed to converge with fast approach, try a binary paritition
// scheme
double min_u = 0.0;
double max_u = 1.0;
double min_v = 0.0;
double max_v = 1.0;
count = 0;
while ( count < 30 ) {
u = (max_u + min_u) / 2.0;
v = (max_v + min_v) / 2.0;
p = apt_surf->pointAt( u, v );
// cout << " binary querying for " << u << ", " << v << " = "
// << p.z() << endl;
// cout << " found " << p.x() << ", " << p.y() << " = " << p.z()
// << endl;
double dx = lon_deg - p.x();
double dy = lat_deg - p.y();
// cout << " dx = " << dx << " dy = " << dy << endl;
if ( (fabs(dx) < eps) && (fabs(dy) < eps) ) {
return p.z();
} else {
if ( dy >= eps ) {
min_u = u;
} else if ( dy <= eps ) {
max_u = u;
}
if ( dx >= eps ) {
min_v = v;
} else if ( dx <= eps ) {
max_v = v;
}
}
++count;
}
return p.z(); return p.z();
} }