1.4.5 Using Dapple
Dapple: http://dapple.geosoft.com/default.asp
Note the current version of Dapple (v.2.1.0.179) only supports WMS version 1.1.1.
Unfortunately there is a serious bug in the software that won't allow you to view any map service if the server software that supplies that service can support WMS version 1.3.0. For example you will not be able to use Dapple to view any OneGeology service served using the latest version MapServer as directed in this cookbook. Until Dapple is upgraded you it is likely that you will not be able be able to use Dapple as a client to view most OneGeology map layers. This bug has been reported to Geosoft, so hopefully it will be fixed in the next release of that software.
Dapple is a data explorer designed to provide an open and optimal environment for visualizing, presenting, and sharing massive quantities of geoscientific data on desktop computers. Dapple lets you browse, discover, and display graphically rich data from global and corporate spatial servers. The Dapple project is an open-source activity sponsored by Geosoft and derived from the NASA World Wind open source project.
As with other GIS software, the first step to viewing a WMS map layer in Dapple is to add the WMS service to the list of available WMS services. To do this, select the 'Servers' menu option and then select 'Add WMS server'.
In the pop-up window, add the GetCapabilities URL of the service without any parameters; you can supply the 'service=WMS' and 'request=GetCapabilities' parameters if you want, but if you supply the version parameter it will be ignored.
For example:
http://ogc.bgs.ac.uk/cgi-bin/BGS_Bedrock_and_Superficial_Geology/wms?
Dapple will add the service to the list of WMS servers and initially show just this new service and the data layers it can serve. If you left click on any of the layers in the Servers window, you will see the metadata associated with that layer in the Metadata window (beneath the map window).
If you see no metadata at this stage there is a good chance that the service is 1.3.0 compliant, and you will not be able to view the data.
There are several ways you can add a map layer to your map view: you can use the Tools menu option, you can left click-down and drag to the Data Layers window, or you can right-click on a highlighted layer and add the layer. In each case the result is the same the layer is added to the data layers view window, and the map is drawn. Remember, if you drag the layer, you will need to add it to the top of the list, or you might not see it.
If you get no map then you will most likely have a WMS service that supports version WMS 1.3.0, and unfortunately there is currently no way you will be able to view the data using Dapple.
To view the legend of the active map layer you may click the link in the Metadata section, or you may right-click on any layer, either in the Servers view window or the Data Layers view window, and the legend will open either in browser window, or another application that is enabled to view the legend image type from a web location.
Section last modified : 26 May 2010.
