Andrew, > > Can someone please explain in some more detail what is meant by this > statement in the description of OCTNewCoordinateTransformation() ? > > "This will honour the axis order advertized by the source and target SRS, > as well as their "data axis to SRS axis mapping". To have a behaviour > similar to GDAL < 3.0, the OGR_CT_FORCE_TRADITIONAL_GIS_ORDER configuration > option can be set to YES." > > I'm trying to understand what the difference is from GDAL < 3.0 and how I > might know that I'm seeing an issue and need to use the specified > configuration option.
See https://trac.osgeo.org/gdal/wiki/rfc73_proj6_wkt2_srsbarn#Axisorderissues Basically OGR_CT_FORCE_TRADITIONAL_GIS_ORDER forces SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER) on the copies of the source and target CRS used by OGRCoordinateTransformation If you use EPSG:4326 or any geographic CRS imported from EPSG, as well as some projected CRS with a northing,easting order from EPSG, you'll see differences between GDAL < and >= 3.0. You may cope with that either by switching the order of coordinates you provide to / get from OGRCoordinateTransformation, or if you want to continue working with the order of coordinates you used to have, you can set OGR_CT_FORCE_TRADITIONAL_GIS_ORDER=YES, or call SetAxisMappingStrategy(OAMS_TRADITIONAL_GIS_ORDER) on the source & target CRS Even -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
