Ok, feels good to me so far. How about WFS and vectorial outputformats of WMS (KML, GeoPackage, PDF). Any risk about making them scale dependent by accident?
-Jukka- ________________________________ andrea aime wrote: On Sat, Jan 4, 2014 at 9:49 PM, Rahkonen Jukka <[email protected]<mailto:[email protected]>> wrote: Hi, ST_Simplify tends to return every now and then invalid geometries from polygon layers. What happens when Geoserver meets for example a big simplified lake with self-intersection? I know that Mapserver is sensitive for self-intersections and the lake might be dropped or even the whole request can fail. On the other hand, Thomas Bonfort wrote: "MapServer already simplifies geometries at the pixel level before sending them to the renderers, and from my testing at the time was more efficient at doing so than using st_simplify(), with the added bonus that the cellsize (resolution, units per pixel) does not need to be factored in the actual SQL query, and that the simplification applies to all data backends. Doing the simplification inside postgis does however make sense if the data transfer from db to mapserver is a bottleneck, and/or potentially if reprojection is involved (as less points would need to be fed into proj)". Have we considered pixel level simplification, what ever it is? GeoServer was the first open source server to have it (that I know of), and in the past I also tried what Thomas tried, and came to the same conclusions (but I was trying to use JTS Douglas Peuker simplification), it was not helping (it was actually making things slower). However, our renderer should not be affected by invalid geometries (believe we stripped all topological operations from it), and I cannot questions the numbers I've got during the benchmarks, the speedup on complex geometries is _very_ significant. Given that when ST_Simplify was tried by Mapnik, it was actually tried by a PostGIS developer, maybe they improved ST_Simplify performance in the process? Not sure, I also plan to check the code of ST_Simplify and see if/how it differs from the JTS implementation. Cheers Andrea -- == GeoSolutions will be closed for seasonal holidays from 23/12/2013 to 06/01/2014 == Ing. Andrea Aime @geowolf Technical Lead GeoSolutions S.A.S. Via Poggio alle Viti 1187 55054 Massarosa (LU) Italy phone: +39 0584 962313 fax: +39 0584 1660272 mob: +39 339 8844549 http://www.geo-solutions.it http://twitter.com/geosolutions_it ------------------------------------------------------- ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Geoserver-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-devel
