Global Mapper Snapping to Line Work

Snapping to existing points, lines and polygons is important while digitizing. Knowing how Global Mapper handles snapping can help improve the data collection work. Sometimes, you may want to snap only to the vertices. At other times, you may want to snap along the line work. And sometimes, you may not want to snap at all.

Setting the Snap Mode
The snapping mode of Global Mapper can be set using the Configuration dialog box

1. Select Tools > Configure.
   
   The Configuration dialog box appears.
   
   
   
2. Click the tab Vector Display.
   
   
3. In the list box, scroll down until the Only Snap to Area and Line Vertices by Default setting is shown.
   
   
4. Depending on your situation, toggle on or off the Only Snap to Area and Line Vertices setting.
   
   Note: the keyboard shortcut V behavior would be reversed depending on this setting.
   
   
5. Click OK.
   
   The snapping mode is set.
   
   

Using Snapping with Only Snap to Area and Line Vertices by Default off

1. Digitize a new line and bring the cursor near to a line or polygon as shown below.
   
   The new line snaps on the line work and vertices of line or polygon.
   
   
   
2. Press down and hold V.
   
   The new line will snap only to the vertices of the line or polygon.
   
   
3. Now press down and hold ALT.
   
   The new line will not snap to anything.
   
   

Using Snapping with Only Snap to Area and Line Vertices by Default on

1. Digitize a new line and bring the cursor near to a line or polygon.
   
   The new line snaps only to the vertices.
   
   
   
2. Press down and hold V.
   
   The new line snaps on the vertices and along the line work.
   
   
3. Press down and hold ALT.
   
   The new line will not snap to anything.
   
   

While digitizing lines, polygons and points in Global Mapper, you will probably want to snap to existing vectors' vertices, on the existing vectors' line work, or not at all.