uDig (User Friendly Internet Desktop GIS), is a GIS Desktop client for editing and viewing Geospatial data.
This Quick Start describes how to:
- load a map layers from a shapefile and Web Map Service (WMS)
- use the standard map tools
- apply colour to map features using styling
- Choose Geospatial ‣ Desktop GIS ‣ uDig from menu
- The application will take a few moments to start up
- When you start up uDig for the first time the Welcome view takes up the entire display. This screen has links to tutorials, documentation and the project website.
- Click the arrow labelled Workbench in the upper right corner, to reveal the contents of the uDig workbench.
You can return to the Welcome view at any time by selecting the Help ‣ Welcome from the menu bar.
The Workbench window offers multiple Editors (each showing a Map) and supporting Views (offering information about the current Map).
Shown above is a typical uDig session with the
- Layers view (1),
- Projects view (2),
- Catalog view (3) and
- Map editor (4).
These views will be described further as we demonstrate their use.
To start out with we are going to load some of the sample data included on the DVD.
- Choose Layer ‣ Add from the menu bar to open up the Add Data wizard
- Select Files from the list of data sources
- Press Next to open up a file dialog
- The OSGeo-Live DVD contains sample data in:
- ~/data (a short cut to /usr/local/share/data)
- Select the following file from the natural_earth2 folder:
- Press Open
- A new Map editor will be opened based on the contents of your shapefile. The default name and projection of the Map has been taken from your shapefile.
- You can see the Catalog view has been updated with an entry for ne_10m_admin_0_countries.shp. This view is used to track the use of resources by the uDig application.
- The Layers view shows a single layer is displayed on this map. This view is used to change the order and appearance of information in your Map.
- The Projects view has been updated to show that your map is stored in projects > ne 10m admin 0 countries. You can have multiple projects open at a time, each project can have several maps.
- Open up the ~/data/natural_earth2/ folder on the desktop
- Drag HYP_50M_SR_W.tif onto the Map Editor, a new layer is added to to the map.
- You can see the order the layers are drawn in the layer view. Right now the HYP_50M_SR_W layer is drawn on top of the ne 10m admin 0 countries layer.
- Select the HYP_50M_SR_W layer in the catalog view and drag it to the bottom of the list
One of the most common questions asked when uDig is considered for an organization is how much memory the application uses. Unlike most GIS applications uDig can get by with a fixed amount of memory. The above shapefile is not loaded into memory, we have a policy of keeping data on disk and drawing data like this shapefile onto the screen as needed.
You can also drag and drop shapefiles directly into the uDig application!
You can control where in the world the Map Editor is looking by using the navigation tools in the tool bar along the top of the screen.
- The Zoom tool is available by default
- Use the zoom tool by drawing a box using the left mouse button around the area of the world you wish to see.
- To zoom out draw a box with the right mouse button. The current map extents will be located within the box you draw.
- The Pan tool can be used to scroll around your map with out changing scale.
- There are also several navigation buttons that can be used at any time:
- Show All, can be used to return to the full extents at any time
- Zoom In and Zoom Out can be used to change the scale by a fixed amount.
- You can use Navigation Back and Forward in the menu bar to cycle though previously visited locations.
Most tools allow you to Pan by holding the center button and control the scale using the scroll wheel.
One of the reasons to use an application like uDig is to access all the great free geospatial information available on the web. This section covers the use of Web Map Servers which make available layers of information that you can mix into your own maps.
If you are not connected to the Internet run Geospatial ‣ Web Services ‣ GeoServer ‣ Start GeoServer for a local WMS. The script will open a page with a “Service Capabilities” section and two links for WMS Services you can drag into your empty map.
You can also connect to Web Map Servers using the Add Data (Layer ‣ Add…) Wizard for Drag and Drop.
- Select File ‣ New ‣ New Map from the menu bar
- Change to the Web view, click on the tab next to the Catalog view to reveal the Web view.
- Click on the link WMS:dm solutions link
- From the Resource Selection page we are going to choose the following layers:
- Press Finish to add these layers to your map
- Use the Zoom Tool to move closer to one of the Parks
- Switch to the Info Tool and click on one the parks to learn more about it
You can switch between the zoom and info tools by pressing Z and I on the keyboard.
- Select the project > ne 10m admin 0 countries, you can double click to open this Map, or Right Click and choose Open Map
- Select the countries layer in the Layer view
- Open up the Style Editor by right clicking on ne 10m admin 0 countries layer and choosing Change Style
- We are going to change a few things about how countries are displayed
- Line: Click Border, click on the Color button and change the color to BLACK
- Fill: On Tab Fill uncheck the box enable/disable fill to turn off fill
- Label: On Tab Labels check the box enable/disable labeling, and choose the attribute NAME from the list of attributes
- Press Apply to see what this looks like on your Map, the Layer view will also be updated to reflect the current style
- When you are happy with the result you can press Close to dismiss the dialog
Some files include style settings. The Style definition can be found in files with the *.sld extension. The name itself should be equal to the file containing the data. If such a Styled Layer Description (SLD) file exists, the style will be applied automatically.
Sometimes it is a bit hard to see what is going on with layer providing much details. To get focused on the task you like to work on, you can choose Map ‣ Mylar from the menu bar. Using the Layer view select different layers in turn to see the effect. You can turn off this effect at any time using Map ‣ Mylar from the menu bar.
Here are some additional challenges for you to try:
- Try viewing your own GIS map layers, or try adding a layer from a Web Feature Service (WFS)
- Try styling the WFS layer.
This is only the first step on the road to using uDig. There is a lot more great material (and ability) left for you to discover in our walkthrough documents.
- Walkthrough 1Try out the use of PostGIS, extract data from a Web Feature Server and explore the use of Themes with our powerful Color Brewer technology.
- Walkthrough 2 – Learn how to create shapefiles and use the Edit tools to manipulate feature data, covers the installation of GeoServer and editing with a Web Feature Server.Available on http://udig.refractions.net/