Web Mapping Illustrated

OpenEV Basics

OpenEV has a variety of simple and complex tools. Many of the advanced tools have been designed with raster data in mind, but the basic toolsets and controls include many of the features needed to do quick visualization of both raster and vector data.

Zooming

One the first things you will want to do is zoom in to certain portions of your map. There are a couple ways to do this. The first is to use the plus and minus buttons on the toolbar of the view. The icons are a magnifying glass with a + and - symbol inside them. Clicking + zooms into the center of the screen, and clicking - zooms out from the center of the screen.

The more efficient way is to use the Zoom tool, which allows you to drag a rectangle on the screen and zoom in to that portion of the map. To enable the zoom tool, select the Edit Toolbar from the Edit menu, then choose Zoom from the list, as shown in Figure 8-6.

Figure 8-6. Activating the zoom tool

Now you can return to the view and click and hold the left mouse button to zoom in. You can also drag a rectangle around a portion of the screen and have it zoom in directly to that location. To do this, click and hold the left mouse button, then drag the mouse to another location. Watch as the rectangular zoom box appears, as in Figure 8-7. When the box covers the area you want, let go of the mouse button.

Zooming out can be done a few ways as well. As mentioned ...