Hi, > The only exceptions apparently > being that self-intersecting polygons are allowed in OSM.
The wiki page you cited says "In general, a 2D geometry is simple if it contains no self-intersection." - what do they mean by "2D geometry"? Specifically, would a self-intersecting *line* be allowed? (I like to think of points as 0D, lines as 1D, and areas as 2D but I have a feeling the GIS people might view this differently?) Self-intersecting *lines* may indeed make sense, think of an "8" shaped narrow-gauge railway in a park. For a data format without topology, the "8" could be drawn in a way that would not intersect but if you intend to keep topology intact then you need the intersection. Bye Frederik -- Frederik Ramm ## eMail [EMAIL PROTECTED] ## N49°00'09" E008°23'33" _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
