[Mapnik-users] layer transperancy

ivom ivo.vdmaagdenberg at pandora.be
Sat Apr 12 09:56:19 CEST 2008


i have the following in my openlayers javascript part of my page:

                var localtiles = new OpenLayers.Layer.TMS("Local tiles",
                                    "http://osm-dev/osm_tiles2/",
                   {type:'png', getURL: get_osm_url, isBaseLayer: false, 
numZoomLevels:17, displayOutsideMaxExtent: true
}, {'buffer':1} );

             map.addLayer(localtiles);

guess that's ok then to exclude the fact on using jpg.

my map.xml file get's rendered through mod_tile (it's in the osm 
svn-tree) which responds to http://osm-dev/osm_tiles2/
tiles requests.

my mapnik xml file holds the following map-tag

<Map bgcolor="transparent" srs="+proj=merc +datum=WGS84 +k=1.0 +units=m 
+over +no_defs">

and with this the background goes pitchblack.

i have tried the openlayers definition with isBaseLayer: true , but the 
same results apply.

pretty odd.

On Fri, 11 Apr 2008, Christopher Schmidt wrote:

> On Fri, Apr 11, 2008 at 09:52:15PM +0200, ivom wrote:
>> thanks, but this bgcolor="transparent" makes my image image totally black
>> with some stuff drawn on it. I can not see through it.
>>
>> the goal i am trying to achieve is to have something like the maplint
>> overlay that is in the osm http://www.openstreetmap.org/index.html page
>
> Are you sure you're not saving as jpg? jpgs don't support transparency.
> Use PNG?
>
> -- Chris
>
>> On Fri, 11 Apr 2008, Alberto Giménez E. wrote:
>>
>>> Hi,
>>>
>>> Try bgcolor="transparent", it should work.
>>>
>>> 2008/4/11, ivom <ivo.vdmaagdenberg at pandora.be>:
>>>>
>>>> hi,
>>>>
>>>> What parameter controls the transperancy of the output of mapnik? I have
>>>> an XML-file built from the omnious example osm.xml and controlling the
>>>> background color is easy bgcolor="ffeedd" what about the alpha channel?
>>>>
>>>> Is there an XML schema or dtd that I have overlooked somewhere?
>>>>
>>>>
>>>> ivom
>>>> _______________________________________________
>>>> Mapnik-users mailing list
>>>> Mapnik-users at lists.berlios.de
>>>> https://lists.berlios.de/mailman/listinfo/mapnik-users
>>>>
>>>
>>>
>>>
>>> --
>>> Alberto Giménez E.
>>>
>
>> _______________________________________________
>> Mapnik-users mailing list
>> Mapnik-users at lists.berlios.de
>> https://lists.berlios.de/mailman/listinfo/mapnik-users
>
>
> --
> Christopher Schmidt
> MetaCarta
>


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