Silly me, I found the error. With
select astext(geom) from (select geomunion(geom3d)::geometry as geom from objects) as foo
everything worked fine. thx Nicolas Ribot schrieb:
Try to geomunion() your polygons. It will create a multipolygon where touching polygons will be unioned. then, use dump() on the geomunion to extract each polygon. Example: the polygon table contains: test=# select id, astext(geometry) from tpoly2; id | astext ----+-------------------------------------------------------------------- 1 | POLYGON((166 272,107 210,145 142,218 158,209 215,182 240,166 272)) 2 | POLYGON((242 118,218 158,145 142,167 104,242 118)) 3 | POLYGON((76 161,145 142,167 104,112 78,76 161)) | POLYGON((284 174,283 112,320 124,295 129,302 156,284 174)) (4 rows) The query to extract unioned polygon based on a common edge: select astext(geom(dump(geom))), path(dump(geom)) from (select geomunion(t1.geometry)::geometry as geom from tpoly2 t1 ) as foo; Leads to this result: astext | path -------------------------------------------------------------------------------------------------+------ POLYGON((284 174,302 156,295 129,320 124,283 112,284 174)) | {1} POLYGON((76 161,145 142,107 210,166 272,182 240,209 215,218 158,242 118,167 104,112 78,76 161)) | {2} (2 rows) (see polygon.png and result.png images done with openjump) HTH Nicolas On 01/02/2008, Simon Schneider <[EMAIL PROTECTED]> wrote:Hi, I've several polygons wich are all connected by at least one line and I'm looking for a way to make one big polygon which contains all the others. In other words the shape of the polygoncluster. I've been locking around for quite a while but I found no way to solve this within postgis. Cheers, Simon _______________________________________________ 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
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