legend and attributes of a WMS service

[swt-gis]

I use a WMS service as a FDO datasource in AutoCAD Map. This works well.

- How can I view the legend (GetLegendGraphic)?
- How can I access the attributes (GetFeatureInfo)?

Any help would be greatly appreciated.
 
Regards
Jens

[phil_borycens]

Hi Jens,

Good question - this all depends on the WMS service and how they setup their sites. You might be able to change the connection string after the "?" to GetLegendGraphic or GetFeatureInfo from whatever you had originally, but those are only going to work if they actually have those parameters defined.

This site has a good explanation of how their WMS services work:

http://www.nationalatlas.gov/infodocs/ogcwms.html

I hope this makes sense.

Thanks!

Phil

[swt-gis]

Phil,

thanks for the answer.

1. Legend
If I understood you correctly, I have to make the GetLegendGraphic request outside AutoCAD Map. This works, but it would also be nice to have a button in AutoCAD Map to show the legend. If there is no button inside AutoCAD Map, then I make the request via a browser - that's ok.

2. Attributes
I know that I can use a GetFeatureInfo in a browser to get the attributes of an object. But this is not quite useful because I have to know the x/y coordinates: “….REQUEST=GetFeatureInfo&X=98765&Y=12345….”
Is there no button inside AutoCAD Map to make a GetFeatureInfo request?

Regards

Jens

[phil_borycens]

There are no buttons in AutoCAD Map 3D to make these requests. WMS is an image service. If you are looking for attribute data that is associated with map features, maybe you really need a WFS (vector) service?

[swt-gis · Accepted solution]

Phil,

thank you for confirming that AutoCAD Map has no button for a GetFeatureInfo-request and a GetLegendGraphic-request.

For the GetLegendGraphic-request you can easily use the browser.

But for the GetFeatureInfo-request, it would be useful to have a button in a future AutoCAD Map release. Other GIS have such a button to retrieve the attributes of an objekt in a WMS service.

Thanks for the help

Jens

[antoniovinci]

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borycep wrote:

WMS is an image service

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It doesn't matter, sir: the info you can get from it, depend on what a given WMS server can offer.

For instance, here's a WMS layer from the Italy's Environment Department:

http://wms.pcn.minambiente.it/ogc?map=/ms_ogc/WMS_v1.3/Vettoriali/LimitiAmministrativi_2011.map

If you query it with an opensource Qgis, you receive full info about the region where you clicked into: check this out.

[swt-gis]

Thanks for the example, antoniovinci.

The example clearly shows that a GetFeatureInfo-request is very important. All areas in the map look the same. Only by using a GetFeatureInfo-request I can access the attributes and use the information about the areas.

Jens

[swt-gis · Accepted solution]

The German Autodesk support has given the solution: AutoCAD Map 2013 has a function to query the attributes of an object in a WMS service!

-    In Display Manager, right-click a WMS layer.
-    Click Get WMS Feature Information.
-    Click Raster Layer tab - View panel - WMS Feature Information.
-     Click a point on the image
-    The WMS Feature Information dialog box is displayed.

This seams to be a new feature in the 2013 release of AutoCAD Map. I can not test is because I only have 2012.

Jens