Digitizer Tool

The Digitizer Tool allows you to modify existing vector features as well as to create new ones. This tool encompasses a lot of functionality, from modifying the shape and position of area, line, and point features, to editing the attribution and drawing styles of individual vector features. The major activities available with the Digitizer Tool are described below.


Creating New Features

At any time that the Digitizer Tool is active, you have the option to create new area, line, and point features simple by right clicking and selecting either the Create New Area Feature, Create New Line Feature, or Create New Point Feature options on the popup menu (pictured below). Any new features created can be exported to new vector files in any of the supported vector export format (DXF, Shapefile, etc.).


Creating New Area Features

After selecting the Create New Area Feature popup menu option, you can proceed to draw a new area feature with the mouse. To draw the feature, simple left click at each place that you'd like to drop a vertex. To finish the area feature, right click at the desired location of the last vertex to complete the area. You can cancel creation of the new area at any time by pressing the Escape key. Note that while drawing the area you can use the Snapping feature to help align the area with existing features.

Once you've completed drawing the area, the Modify Feature Info dialog will appear allowing you to setup the label, classification, drawing style, and attribution for the area. The perimeter and enclosed area of the area feature will be added as default attributes. The units for these measurements can be modified on the General tab of the Configuration dialog. See Editing Feature Attributes and Drawing Styles for more details.

Once you have completed have completed creating the area, the Digitizer Tool will remain in the area creation mode, so you can simply start left-clicking to draw another area, or right-click to choose a different mode.

You can also create new area features from selected line features by selecting a collection of lines, then right-clicking and selecting the Create New Area Feature(s) from Selected Line Feature(s) menu command. This will attempt to connect the selected line features to build area features. All line features will be connected as far as possible, then closed to create a new area feature.

Creating New Line Features

After selecting the Create New Line Feature popup menu option, you can proceed to draw a new area feature with the mouse. To draw the feature, simple left click at each place that you'd like to drop a vertex. To finish the line feature, right click at the desired location of the last vertex. You can cancel creation of the new line at any time by pressing the Escape key. Note that while drawing the line you can use the Snapping feature to help align the line with existing features.

Once you've completed drawing the line, the Modify Feature Info dialog will appear allowing you to setup the label, classification, drawing style, and attribution for the line. The length of the line feature will be added as a default attribute. The units for the length measurement can be modified on the General tab of the Configuration dialog. See Editing Feature Attributes and Drawing Styles for more details.

Once you have completed have completed creating the line, the Digitizer Tool will remain in the line creation mode, so you can simply start left-clicking to draw another line, or right-click to choose a different mode.

You can also create new line features from selected area features by selecting one or more areas, then right-clicking and selecting the Create New Line Feature(s) from Selected Area Feature(s) menu command. This will create a single closed line feature from each selected area feature.

Creating New Point Features

After selecting the Create New Point Feature popup menu option, you can proceed place the point feature by left clicking at the desired location of the point. You can cancel creation of the new point at any time by pressing the Escape key.

You can also use the Create New Point Feature at Specified Position option to create a new point feature at a manually specified location. When you select this option, a dialog appears allowing you to enter the location for the new point feature in either latitude/longitude coordinates or coordinates in the current view projection.

Once you've placed the point, the Modify Feature Info dialog will appear allowing you to setup the label, classification, drawing style, and attribution for the new point feature. See Editing Feature Attributes and Drawing Styles for more details.

Once you have completed have completed creating the point feature, the Digitizer Tool will remain in the point creation mode, so you can simply left-click to place another point, or right-click to choose a different mode.

Creating New Range Ring Features

After selecting the Create Range Ring(s) popup menu option, you can proceed to place the center location of your range rings by left clicking at the desired location. You can cancel creation of the range ring(s) at any time by pressing the Escape key or right clicking.

After selecting the center of your range ring(s), the Select Range Ring Parameters dialog (pictured below) appears and allows you to setup how many range rings you would like to create and how far apart you would like to create them.

Once you have completed have completed creating the range ring(s), the Digitizer Tool will remain in the range ring creation mode, so you can simply left-click to create additional range rings centered on another location, or right-click to choose a different mode.


The range ring feature has numerous applications, including search-and-rescue and aviation.

Creating New Shape (e.g. Circle, Rectangle, etc.) Features

Under the Create Area Shapes and Create Line Shapes right-click popup menus you will find options to create Arc, Circular, Elliptical, Rectangular, and Square area and line features. For all of these shape types, you click and hold the left mouse button at the center of the feature, then drag it until it is of the desired shape. For Circular/Elliptical features and Arcs, the default shape follows a circle and holding down the SHIFT key will dragging will result in an ellipse. For Rectangular/Square features, the default shape is a rectangle and holding down the SHIFT key will force the dragged shape to be square.

Once the shape is to your liking, release the left mouse button and the Modify Feature Info dialog will appear allowing you to setup the label, classification, drawing style, and attribution for the new feature. See Editing Feature Attributes and Drawing Styles for more details.

Once you have completed have completed creating the shape, the Digitizer Tool will remain in the selected shape creation mode, so you can simply start drawing a new shape, or right-click to choose a different mode.


Editing Existing Features

In addition to creating new vector features, the Digitizer Tool is also very useful for editing existing vector features. This tool provides the ability to move, delete, and reshape vector features, as well as modify the label, classification, drawing style, and attribution of any vector feature loading from any file format supported by Global Mapper. Note than any edits made are NOT automatically saved back to the origin file, but they will be saved in Global Mapper workspaces and into any exported vector files.

Selecting Features

Before you can edit an existing feature or features, you first must select them. Once a feature is selected, you can tell that it is selected because it will be drawn with a different style. The different methods for actually selecting features are described below.

One way to select features is by simply by clicking the left mouse button near the feature, or in the case of area features, within the feature. Using this method, the closest point or line feature will be selected, or if no point or line features are nearby and you clicked within an area feature, the area feature will be selected.

To select multiple features at a time, you can drag a selection box by holding down the left mouse button to draw a box. Any features entirely within the box drawn or features which are cut by the box will be selected.

You can add to an existing selection by holding down the CTRL key while performing a selection with any of the above described methods. You can deselect features by holding down the SHIFT key while performing a selection. You can toggle the selection state of features by holding down both the SHIFT and CTRL keys while performing a selection. Finally, by holding down the ALT key, you can select only area features. This is useful if lots of line and point features make it otherwise difficult to select the area feature.

You can also select area and point features within selected area features by first selecting one or more area features using the previously described methods, then right clicking and selecting the appropriate option under the Advanced Selection Options submenu. This makes it easy to find and edit all of the point and/or area features within some other area feature(s).

Selecting Vertices

If the Show Area and Line Vertices option is enabled (Shift+V is a keyboard shortcut to toggle this setting), you can also select individual vertices on area and line features. You must select vertices before options allowing you to work with individual vertices in area and line features appear in the right-click options menu. Selected vertices will be shown on the display with a circle around them.

To select vertices, simple left click near a vertex to select the closest one if any are nearby, or drag a box to select all vertices within the box. The same behavior modifications occur as described above if the CTRL and/or SHIFT keys are pressed when selecting.

Pictured below is a screen capture showing a line feature and several of its vertices selected, with a right-click popup menu opened to show the available options.


Editing Feature Attributes and Drawing Styles

When a single area, line, or point feature is selected, there is an option on the right-click popup menu allowing you to edit that feature (i.e. Edit Area Feature, Edit Line Feature, or Edit Point Feature). Selecting that option displays the Modify Feature Info dialog which allows you to modify the Name, Feature Type, Drawing Style, and Attributes for the selected feature. You can also access this dialog by double-clicking on a feature. A sample of this dialog for an area feature is below.


The Name field allows you to modify the display name of the feature.

The Feature Type selection allows you to choose which Global Mapper classification to assign to the feature. You can also choose to create a new Global Mapper type with the Create New Type button.

The Feature Style section allows you to modify the drawing style of the selected feature. Selecting the Use Default Style for Selected Feature Type option will cause the currently configured style for the Feature Type from the Area, Line, or Point Styles tab of the Configuration dialog to be used when rendering the feature. Alternatively, you can choose the Specify Style to Use When Rendering Feature option and select how you want this feature drawn, independent of the selected Feature Type.

The Feature Attributes selection allows you to edit the attributes that are associated with this feature. The Add File Link(s)... button in this section allows you to easily add attributes that point to files somewhere on disk without having to manually type in the file name. These file links can later be followed from the Feature Information dialog displayed with the Feature Info tool.

When more than one area, line, and/or point feature is selected, there is an option on the right-click popup menu allowing you to edit the selected features. Selecting that option displays a dialog dialog which allows you to modify the Name, Feature Type, and Drawing Style, and Attributes for the selected features.

Deleting/Undeleting Features

Removing an unwanted feature is quite simple. All that you need to do is select the feature(s) that you wish to delete, then either select the Delete option from the right-click popup menu or press the DELETE key. Once you've done that, the feature is marked for deleted and will no longer appear on the display unless the Render Deleted Features option is enabled on the Vector Options tab of the Configuration dialog.

If you decide that you didn't want to delete a feature, simple enable the Render Deleted Features option (see above) to show the deleted features, then select the deleted features and select the Undelete Feature(s) option from the right-click popup menu.

Moving Features

You can move area, line, and point features simply by selecting the feature(s) that you wish to move, then selecting the Move XXX Feature(s) option from the right-click popup menu. Once you've done that, simply hold down the left mouse button and drag the features to the desired new location. To complete the operation, right click or press the ESC key.

If you'd only like to move the selected feature(s) either horizontally or vertically, you can hold down either the 'X' or 'Y' keys on the keyboard to restrict the movement to that axis. Holding down both keys will move the feature(s) diagonally.

If after moving a feature you decide that you want to undo the move, simply select the feature(s) that you want moved back and select the Restore Original Shape from the right-click popup menu.

Changing the Shape of Area and Line Features

You can change the shape of area and line features in several different ways. You'll first have to enable the Show Area and Line Vertices option (Shift+V is a keyboard shortcut to toggle this setting) before having access to the features described below. You'll also need to select the vertices to work with before performing any of the described operations except inserting new vertices.

The following options are available for reshaping area and line features:

If after modifying the shape of an area or line feature you decide that you want to undo the changes and restore the feature to its original shape, simply select the feature(s) that you want restored and select the Restore Original Shape from the right-click popup menu.

Combining Line Features

You can combine multiple line features into a single line feature by first selecting the line features to combine, then selecting the Combine Selected Line Features right-click menu option. This option will connect any lines that you have selected that join at an endpoint. Any lines that are succesfully joined into a new one will be marked as deleted.

Adding Islands to Area Features

You can make one area feature become an island, or hole, within another area by first selecting the area that you want to make into an island, then right click and select the Make Selected Area an Island in Another Area menu option. You will then need to left-click in the area feature that you would like to make the selected area an island of. The parent area must completely enclose the selected area in order for it be successfully added as an island.


Snapping to Existing Features When Drawing

During some operations (i.e. drawing new area or line features or graphically placing a new point feature), the cursor can automatically snap to existing features when you move it near them to facilitate lining up features. This happens by default unless the ALT or V keys are depressed. Pressing the ALT key causes no automatic snapping to occur, while pressing the V key causes only vertices on existing features to be snapped to.


Snapping Vertically/Horizontally When Drawing

When drawing new area or line features or moving existing features, you can use the CTRL and ALT keys to cause the next vertex to be snapped vertically or horizontally relative to the last vertex or moved vertically or horiztonally compared to the features current location. Hold down the CTRL key to snap vertically, the ALT key to snap horizontally, or both the CTRL and ALT keys to snap diagonally.


Un-doing Digitization Operations

During some operations, like drawing new features, you can undo your last placed point by pressing Ctrl+Z.


Displaying Additional Feature Information

Depending on what types of feature are selected and what data is available, additional options may appear on the option menu that appears when right clicking. These additional options are described below.

Generating a 3D Path Profile from a Line Feature

If gridded elevation data (i.e. DEMs) is loaded, the Generate Path Profile From Line option will appear when a single line feature is selected. Selecting this option will display the Path Profile/Line of Sight dialog with a 3D path profile of the elevations under the path that the selected line feature follows.

Calculating Cut-and-Fill Volumes for Area and Line Features

If you have a single area or line feature selected, the Measure Volume option will appear when bringing up the right-click menu. Selecting this option will allow you to calculate cut-and-fill volumes either within the selected area or along the selected line feature. For more information about this operation, see the cut-and-fill section of the Measure Tool help.

Working with Feature Measurements (i.e. Length, Enclosed Area)

If one or more area and/or line features are selected, the Add/Update the Measure Attributes of Selected Feature(s) option will appear when right clicking. Selecting this option will add measurement attributes to the selected features that do not already have them, or update the measurement attributes of features that do. The measure attributes include LENGTH for lines and PERIMETER and ENCLOSED_AREA for areas.

Finding Non-Connected Line Endpoints (i.e. Connectivity Checks)

If two of more line features are selected, the Find Non-Connected Line Endpoints option will appear when right-clicking. Selecting this will display a dialog allowing you to either mark all line endpoints that do not connect to an endpoint (not an interior vertex) of another selected line or those line endpoints that don't connect and are within some distance of another selected line endpoint. This is a very useful feature for allowing easy identification and fixing of connectivity issues within loaded vector data.

Any line endpoints that do not connect based on the selected criteria will be displayed with a blue circle over that endpoint. Once you think you have fixed the connectivity issues at a location, simply re-run the command to find the non-connected line endpoints to update the display of the blue circles (they are not automatically updated as you join line endpoints).

Finding Nearby Points

If two of more point features are selected, the Find Selected Points Within ??? Meters of Other Selected Points option will appear when right-clicking. Selecting this will display a dialog allowing you to specify a search distance. Any selected point features that are within the specified search distance of another selected point feature will be displayed with a blue circle over that point. If you delete or move some points to remove duplicates (the primary use of this tool), simply re-run the command to find the to update the display of the blue circles (they are not automatically updated as you edit the data).