It looks like the answer is "4 degrees unless the user has overridden the value with the OGR_ARC_STEPSIZE configuration variable", as found in gdal-3.0.2/ogr/ogrgeometryfactory.cpp:3884. Hope that helps. Scott -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html