- geoc = sgCartToPolar3d( sc + hit_list->get_point(i) );
- double lat_geod, alt, sea_level_r;
- sgGeocToGeod(geoc.lat(), geoc.radius(), &lat_geod,
- &alt, &sea_level_r);
+ // FIXME: sgCartToGeod is slow. Call it just once for the
+ // "sc" point, and then handle the rest with a geodetic "up"
+ // vector approximation. Across one tile, this will be
+ // acceptable.
+ double alt = sgCartToGeod( sc + hit_list->get_point(i) ).elev();