WMS (Web Map Service) and WMTS (Web Map Tile Service) are interfaces for retrieving geodata as raster data over the internet. The images are generated by a map server using data from a GIS database.
These images can be used as background maps in OCAD.
- A WMS is calculated on the server side and delivers one image per request.
- A WMTS delivers tiles that have been pre-renderd on the server side, and cached on the client side. The background maps are thus loaded significantly faster by a WMTS service than by a WMS service.
WMS / WMTS requires a georeferenced map. Choose the Scale and Coordinate System command from the Map menu to set the map scale and a coordinate system.
Real world coordinates do not have to be necessarily defined. They can be left at (0/0) for example.
To set up a map from a WMS / WMTS server choose the WMS / WMTS command from the Background Map menu. The WMS / WMTS dialog appears.
The WMS servers are listed in the upper left box of the WMS - Web Map Service dialog.
There are already some preset connections the first time you start the dialogue.
Add a WMS / WMTS Server
- Click the Add button.
- The Edit WMS / WMTS Properties dialog appears.
- Enter the Service, Name of the server, the URL and choose the Version
If required, also provide a Login with Password, the Token Server URL and a Key.
You will get these data from the WMS /WMTS provider.
- For WMTS additional information will be shown in the WMTS memory cache.
- Click the OK button when finished.
- The WMS / WMTS server appears in the upper left WMS / WMTS server box.
Connect to a WMS / WMTS Server
Select a WMS / WMTS server from the list and click Connect. If the connection was successful, OCAD gets a list from the server with the available layers. These layers are listed in the WMS / WMTS layer table of the WMS / WMTS dialog. Read the WMS / WMTS Layer article to learn how to use layers as Background Maps.
Edit WMS / WMTS Server Properties
Select a WMS / WMTS server and click the Edit button to edit its properties. The Edit WMS / WMTS Properties dialog appears which is equal to the Add WMS / WMTS Server dialog.
Remove a WMS / WMTS Server
Click the Remove button to remove the selected WMS / WMTS server from the list.
WMS / WMTS Layer
Add Selected Layers to Background Maps
After connecting to a WMS / WMTS server the available WMS / WMTS layers are listed in the WMS / WMTS layer box.
- Select a WMS / WMTS layer in the list and choose an Image format from dropdown list (those formats are provided by the WMS / WMTS server). There is also a Search Field.
- Choose an option how to add the selected layers:
- Add Selected Layers as WMS / WMTS Layers to Background Maps (Online)
- This is an online Background Map . It is updated by the WMS / WMTS Server by each change of the map view. This can take a moment. Choose the online option only if you are using a fast WMS / WMTS server and work woth high speed internet connection. As an alternative, you can add the layer as an offline background map.
- Add current view of selected layers to background maps (Offline)
- Add User Defined Extent of Selected Layers to Background Maps (Offline)
- Define the Offline folder. The current map folder is set as default.
- Define the Resolution.
- Define the Extent (minimum easting, maximum easting, minimum northing, maximum northing). The current view extent is set as a default when opening the WMS / WMTS dialog but the entries are not updated automatically by changing the view. The extent can be updated by clicking the Set extent to current view button.
- With this offline option an image of the chosen WMS / WMTS layer of the defined extent is downloaded from the WMS / WMTS server and added as a custom background map to the map. It does not get updated when changing the view.
- Click the Add button.
Web Map Services generally provide their images in multiple spatial reference systems. OCAD can only access to WMS / WMTS if the OCAD maps' coordinate system (ex. Swiss Grid CH1903+/LV95) is supported by the WMS / WMTS. Then the Spatial reference system is automatically set to the corresponding EPSG code. If the chosen coordinate system is not compatible with the WMS / WMTS, the Spatial reference system caption in the WMS / WMTS dialog remains empty.
Click the Close button when finished.