The g3DGMV map viewer screen
This section gives a short overview of the map viewer screen. In addition the menu, toolbar, and status bar components are discussed (Much of this information should be intuitive).The map viewer screen is shown below. The various components have been identified for quick reference. The map viewer is the view area window that the map is displayed in after it has been loaded and rendered by the g3DGMV program.
The menu bar spans the top of the window and contains a list of menu items. The function of menu is similar in most window type application. By placing the mouse pointer over a menu item and the pressing left mouse button, a pull down menu will appear. By move the mouse pointer down the list, item in the pull down are highlighted. To select an item simple release the mouse button when the item wanted is highlighted.
The handle on the left of the menu bar allows the menu to be detached from the main window or allows the menu bar and tool bar to swap places. Simple place the mouse pointer over the handle then press and hold the left mouse button down. The menu bar is then detached and can be position any place on the desktop. Release the left mouse button when the menu is at the location you want.
As with the menu bar the tool bar spans the top of the window just below the menu bar and contains a number of commonly used items. To access an item in the tool bar placing the mouse pointer over the icon and press the left mouse button. If you position the mouse pointer over the icon and hold it there a short description of the function is displayed just below the icon.
The handle on the left of the Tool bar allows the Tool Bar to be detached from the main window in the same fashion as the menu bar.
The combo box above the text window shows the reference Ellipsoid use for calculating positions on the map. An Ellipsoid is a mathematical structure that define the shape of the earth and that are associated with different datum's. Datum's describe the model used to match a features to ground coordinates. The default Ellipsoid is the Clark 1880. This is associated with the NAD 27 Datum. If a position on the map doesn't look right, try the WGS 84 or one of the other Ellipsoid listed.
The text window is just below the combo box. This area will contain information regarding the DEM or DLG maps that have been loaded during this session.
The map view window just to the right of the text window will be where the rendered map is displayed. If the map is larger then this area vertical or horizontal scroll bars will appear allowing you to view the whole map by moving the vertical scroll bars up or down and the horizontal scroll bars right or left.
Panel Bar
The text and map view windows are separated by a vertical panel bar.
The panel bar allows you to resize the viewing areas of the two windows.
Positioning the cursor on the little square displayed on the panel bar
and hold the left mouse button down. Now move the bar right or left to
resize the windows.
File selection is done from the File Dialog Box. You can display a File dialog box by selecting open, save or save as under files in the menu bar or by clicking on the open or save icon in the tool bar. The File Dialog Box is used to read Digital Elevation Model (DEM ) and Digital Line Graphs (DLG ) maps file from the disk. In addition you can use it to read or save maps as a png, jpeg , or xpm bitmap. The File Dialog Box is also used to read or write a user defined Map Log. These logs will contain any user-defined waypoints (global positioning points) that need to be associated with the map.
Color Selection (into color bucket)
You can select a new color either by choosing the "Pick Color From Map" item from the popup menu or using the color selection widget. To access the color selection widget right click on the color icon in the toolbar. The color selection widget is used for interactive selection of colors. This composite widget lets the user select a color by manipulating RGB (Red, Green, Blue) and HSV (Hue, Saturation, Value) triples. This is done either by adjusting single values with sliders or entries, or by picking the desired color from a hue-saturation wheel/value bar.
The selected color will be displayed in the color bucket just above the status bar. This color will be used by the draw tools, which are discussed later on.
the status bar displays a line of text at the bottom of the window. The contents of this text is dependent on the operation being performed.
The progress bar is just to the right of the status bar. The progress bar is used to display the current status of a time-consumming operation such as rendering a large 3D map. This gives the user some idea of how much time is left before the operation is completed.