QGIS » QGIS Application

Hi,

I tried to reproduce your issue, but to be honest I'm even not able to see the image you get in your animated gif.

Can you please describe in words the layers/crs/imageformat etc you try to use (both layer and project?)

The WMS always first reads the capabilties of the WMS and with that get's information about layers etc etc.

So this looks ok, isn't it:

http://www.wms.nrw.de/umwelt/laerm?request=GetCapabilities

and if you run QGIS in debug mode, you see that QGIS tries to retrieve an WMS image with this url:

https://www.wms.nrw.de/umwelt/laerm?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=50.15059999999999718,5.724990000000000023,52.60199999999999676,9.531539999999999679&CRS=EPSG:4326&WIDTH=1002&HEIGHT=647&LAYERS=STR_DEN&STYLES=&FORMAT=image/png&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE

which is a transparent image. Whatever I try, I never get your map. Did you try other wms clients?

One thing which is not normal is that in the datasource of the properties of a layer of your wms is that I see something like:

contextualWMSLegend=0&crs=EPSG:4326&dpiMode=7&featureCount=10&format=image/png;%20mode%3D24bit&layers=STR_DEN&styles=default&url=http://www.wms.nrw.de/umwelt/laerm

while normally you see something like:

crs=EPSG:28992&layers=cbsgebiedsindelingen:cbs_provincie_2007_gegeneraliseerd&styles=cbsgebiedsindelingen:cbs_gebiedsindeling&format=image/png&url=http://geodata.nationaalgeoregister.nl/cbsgebiedsindelingen/ows?SERVICE%3DWMS%26

Maybe that rings a bell with someone?

So can you please describe what I can do to reproduce your issue?

Ah... NOW I get an image:

https://www.wms.nrw.de/umwelt/laerm?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=51.42312825621159789,7.201033122179148371,51.54250891635459908,7.444299601640792297&CRS=EPSG:4326&WIDTH=1506&HEIGHT=739&LAYERS=STR_DEN&STYLES=default&FORMAT=image/png;

by guessing from the capibilities that the data is in Dortmund I zoomed in and THEN something appears...

So in my view this is not a QGIS issue, but a misconfigured WMS-server:
- your layers are scale dependent: you only see data when you zoom in enough
- your WMS defines a very LARGE bbox as default bbox

which makes QGIS zoom to this BBOX first at a zoom level you do not see anything.

So best is to define a better bbox in the capabilities of your WMS

Does this sound reasonable?

I thought an animated GIF would make it easier to understand for all languages, but okay - let's try it in English :)

1. The project CRS can either be set to EPSG:4326 or EPSG:25832 (native SRS) to reproduce the bug.
2. I've set up a bookmark with this BBOX (Düsseldorf in Germany): 6.83 51.21 6.85 51.23 (for the German testers: 6,83 51,21 6,85 51,23)
3. I'll test it with layer 10 (sublayer 11 with style=default), which is about noise coming from trains all over the day.
3. a) When loading the WMS using the "Browser Panel", I'm getting an empty map image, but the WMS legend gets loaded.
3. b) When loading the WMS using the "Add WMS layer" from the menu or "Manage Layers toolbar", it works for me as expected.

A legend is always loaded as QGIS just loads the GetLegendGraphics request.
The layers are scale dependent, so QGIS requests a layer but the server returns a transparent image

I think this is not a bug, and this issue can be closed

Richard Duivenvoorde wrote:

A legend is always loaded as QGIS just loads the GetLegendGraphics request.
The layers are scale dependent, so QGIS requests a layer but the server returns a transparent image

The layers are scale dependent, but I'm testing both variants at exactly the same scale! Did you even watch the animation? You can clearly see that I'm zooming to the same bookmark.

EDIT: I've figured out the real problem by using a proxy server!

When using Add WMS layer or Manage Layers toolbar, this gets requested:

https://www.wms.nrw.de/umwelt/laerm?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=51.20864726308272452,6.818027744091569531,51.23134997181813333,6.861941099535693311&CRS=EPSG:4326&WIDTH=1290&HEIGHT=667&LAYERS=SCB_DEN&STYLES=&FORMAT=image/png&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE

When using Browser Panel this gets requested from WMS:

https://www.wms.nrw.de/umwelt/laerm?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=2719705.686675078236,3785531.978490603156,2721794.643601302989,3788219.639582599513&CRS=EPSG:3034&WIDTH=826&HEIGHT=642&LAYERS=SCB_DEN&STYLES=&FORMAT=image/png&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE

That's another CRS without any content. Seems like Browser Panel grabs the first CRS it can find, since EPSG:3034 is the first one listed in GetCapabilites.