[OpenLayers-Users] change projection layer dynamically

Roald de Wit roald.dewit at lisasoft.com
Sat Apr 25 19:50:20 EDT 2009


Hi Toni,

Can you tell me how this WMS server works (the one that expects 
different projections based on the area of Spain that you're looking at)?
Is it one layer for the whole country or 3 different layers that you 
would request (1 layer for every projection/region)? I'd be surprised if 
it was 1 layer.

Regards, Roald

toni hernández wrote:
> Hi,
>
> thanks for the advise.
> Now at least I have two different possibilities.
>
> The other one I was thinking about is reloading the html page with a 
> new parameter. This new parameter should be used to define the new 
> projection when setting the map. The only problem is that I have to be 
> comparing the coordinates with every new zoom or pan.
>
>
>
>
> 2009/4/25 Roald de Wit <roald.dewit at lisasoft.com 
> <mailto:roald.dewit at lisasoft.com>>
>
>     Hi Toni,
>
>     OpenLayers cannot combine WMS layers with different projections
>     nor can it easily switch projections, certainly not on the fly
>     based on the region you are viewing!
>     What I advise you to do is the following if you have no control
>     over these WMS servers and cannot have them serve all images in
>     one projection: have MapServer act as a reprojecting proxy for
>     you. MapServer can act as a WMS client and reproject the imagery
>     into the projection you want. This page describes how to do this: [1].
>
>     If you need more assistance with setting up or configuring
>     MapServer I advise you to ask their mailing list.
>
>     I hope this helps.
>
>     Regards, Roald
>
>     [1] http://mapserver.org/ogc/wms_client.html
>
>
>     toni hernández wrote:
>
>         hi,
>
>         I have a map that gets some WMS layers from two different
>         servers all over spain.
>
>         There is one wms server that needs a concrete epsg parameter
>         (23029, 23030 or 23031) depending on the zone of spain. This
>         server does not accept epsg:4326.
>
>         So dependig on the zone of the map that is being displaid I
>         need to change the WMS layer projection.
>         is this possible?
>
>
>
>




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