float y = ballast_h-rail_min.y;
for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
build_part(*i, rail_profile, Point(-gauge/2-rail_max.x, y), bld, index);
for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
build_part(*i, rail_profile, Point(gauge/2-rail_min.x, y), bld, index);
}
float y = ballast_h-rail_min.y;
for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
build_part(*i, rail_profile, Point(-gauge/2-rail_max.x, y), bld, index);
for(vector<TrackPart>::const_iterator i=parts.begin(); i!=parts.end(); ++i)
build_part(*i, rail_profile, Point(gauge/2-rail_min.x, y), bld, index);
}