On mardi 28 février 2017 17:25:51 CET TazMainiac wrote: > Hi All, > > When I use ogr2ogr to process a shape file (into KML for examle) that has > "invalid" polygons (self-intersections or other problems) in it, it "cleans > them up", such that they are valid. Is there a description anywhere of > what algorithm it's using to do this cleanup?
Hum, there's not really such a cleanup algorithm. When writing a shapefile, there's some "topological analysis" to figure out which rings of a (multi)polygon are inside others, so as to respect the shapefile specification, but that's all. I'd be surprised that self-intersections of a ring are corrected for example. if you want to explicitly remove invalid geometries, you can do something like: ogr2ogr out.shp in.kml \ -sql "SELECT * FROM input_layer WHERE ST_IsValid(geometry)" -dialect SQLite Even -- Spatialys - Geospatial professional services http://www.spatialys.com
_______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
