[OpenLayers-Users] very slow map using WKT Multipolygon with a lot of Points

[Fabrizio Buratta]

Thank you for your help!

At the moment, as I have short deadline I simplified geometries using
GEOSGeometry.simplify available in the GeoManager of Geodjango, so the
client only cope with 400/500 vertex istead of 50000, it works smoothly
also with IE7 . When I have more time I would like to try to set a WMS
server which seems an elegant solution.


2012/11/20 Sergeant_york <electronicpanda at gmail.com>

> Hello again,
>
> I strongly agree with wms solution from one of the posts in this topic. If
> you can use serverside capabilities it will be the best solution and as far
> as I know people uses wms for showing geometries that has many vertexes.
>
> for this you can:
> 1- use serverside wms service (for example geoserver it also reads shape
> files)
> 2- get boundaries data as images from server and apply sld for best look
> (google, bing etc works like that)
> 3- show these borders as OpenLayers.Layer.Wms layer, you can even transform
> features in different reference systems (for example from epsg:4326 to
> epsg:900913)
> 4- you can also cache images in server for best speed
>
> with this:
> 1- Performance issues will be solved at limited amount of wms layers
> 2- Drawing will be done in server so you don't have to keep millions of
> vertexes in clientside
> 3- can get feature info (with vertexes and attributes) with usng
> OpenLayers.Control.WMSGetFeatureInfo
>
> but with wms layer you cannot:
> 1- edit any geometries in this layer, or you can edit with the help of
> vector layer but costs more effort
> 2- change layer styling easy as clientside styling with vectors. It costs a
> bit more effort to apply dynamic styling
> 3- work with only clientside application. You need a server, geoserver for
> drawing and datastore (in this case your shape file) which is inside of the
> server
>
> I changed my idea for simplification with respect to zoom levels, because
> applying this algorithm to every feature in vector layer in clientside can
> also cause performance issues(tryed and failed). Yet it is nice to use to
> get data from server so still in the future if you will use this one, every
> database accepts OGC standarts has simplify method or you can check this:
>
>
> http://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm
>
>
>
>
>
> --
> View this message in context:
> http://osgeo-org.1560.n6.nabble.com/very-slow-map-using-WKT-Multipolygon-with-a-lot-of-Points-tp5017181p5017672.html
> Sent from the OpenLayers Users mailing list archive at Nabble.com.
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Fab

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