Checkout http://www.cgal.org they take the Delaunay triangulation and use it to generate an alpha shape. The polygon produced from the alpha shape can be concave or convex, it can also produce a multipolygon or polygons with holes depending on the input points and the selected alpha value. The alpha shape is a generalization an isn't perfect, but hard to determine what the optimal shape from a collection of points would be anyway.
If you want to go that route and use alpha shapes then look at http://www.postlbs.org they have a simple implementation of the cgal alpha shape 2d template for postgis. Rob -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Nicolas Ribot Sent: Friday, July 06, 2007 6:18 AM To: PostGIS Users Discussion Subject: Re: [postgis-users] Polygons enclosing points > Dear all > I have many points in a map layer which i want to surround with a polygon. > Is there a way to automatically create optimum polygons that each enclose > only one point and snap at their vertices? > Thank you > I think a delaunay triangulation could do the trick. Search this list for delaunay. A thread like 'Voronoi / Dalaunay function (solved)' may be usefull. Nicolas _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
