[OpenLayers-Dev] WMS, Mapserver and OpenLayers

[Bradley Mclain]

Yes some of it definitely sounds useful, I will give it a try and get back
to you with my results.

The poor image quality is a strange one because i managed to tweak the
images so they were looking good on Mapserver, it is just with an import to
OpenLayers that they really deteriorate.

On 7/6/07, Richard Duivenvoorde <rdmailings at duif.net> wrote:
>
>
> Hey Bradley,
> is your mapserver configuration ok? I would say: install qgis
> (www.qgis.org). This gives you an easy and alternative way to look at
> wms-layers. Just give it the url of your mapserver and the name of your
> mapfile and it will either show you the layers (and projections) which
> you defined in your mapfile or an error.
> If that is working, I would try to set up an WMS.Untiled layer first.
> Using firefox and the firebug extension you can see exactly the url's
> that OL is firing at mapserver then. You can see what bbox and srs (aka
> projection) is asked from mapserver then.
>
> I'm working with projected layers also, eg:
>
> map = new OpenLayers.Map('map',  {
>       'projection':'EPSG:28992',
>       'units':'m',
>       'maxExtent':new OpenLayers.Bounds(-20000,300000,300000,650000),
>       'resolutions':[1, 2.5, 5, 10, 30, 50, 100, 175, 256, 512],
>       'controls':[],  // empty controls om te zorgen dat er NIKS staat
>       'theme':null    // empty theme to be able to override
> });
> // not tiled no cache
> xxlayer = new OpenLayers.Layer.WMS.Untiled( "xx",
> "yourserver?map=mymapfile.map", {layers: 'a,b,c', FORMAT:'png'},
> {ratio:1, units:'meters'} );
>
> If all that is working, you can make it a tiled server and see if there
> is a problem.
>
> About poor quality: are you showing raster or vector data? If raster:
> are you using the right resolutions for your layers? You can do a lot of
> tweaking in the mapserver mapfile (anti aliassing etc).
>
> White screens: be aware of caching of image data in your browser/proxy!
> See if qgis is also giving white screens, if so: looks like an
> mapserver/projection problem.
>
> Hope this is of any help
>
> Richard Duivenvoorde
>
>
>
> Bradley Mclain wrote:
> > What I am trying to do is import content from my mapserver into
> OpenLayers.
> >
> > I am starting to think from experimentation that the problem has
> > something to do with my projection. If I do not give a projection in my
> > layer definition in OpenLayers and rely simply on the projections given
> > in my mapfile I get a projection error. If i do specify one I simply get
> > a white screen.
> >
> > Now i have checked my projection details in proj4 and I am 99% sure they
> > are correct but they are not very standard values, maybe OpenLayers does
> > not support them. Value is EPSG:28355
> >
> > I tried again to manually import the data using the mapserver layer
> > option and had some success. The layers actually displayed, which is the
> > best result I've had so far. However there is still a problem, they are
> > rather poor quality and the tiles to not align for some reason.
> >
> >
> > ------------------------------------------------------------------------
> >
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>
>
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