Drawing Polylines - Tutorial

You can create polylines by clicking on points along the line or by tracing along the line. When tracing, a continuous stream of vertices is created as you move the pointer along the polyline. This makes it easy to digitize curved boundaries. The contours in this example are curved lines and are best digitized using the tracing method.


If you are using a digitizing tablet, check to see if the tablet is in stream mode before continuing. Click the Tools | Project Settings command. Click on the Digitizing Settings tab and make sure Stream Mode is checked. Click OK and you are ready to begin.


If you are digitizing an image, make sure you can see all the contour lines in the window before beginning. You can click the View | Full Extents command to zoom out so everything is visible.


To set the line properties and create the polylines:

  1. Click the Draw | Polyline command or click the  button.

  2. In the Property Manager, in the Increment Settings section, check the box next to the Enter Data After Creation option, if it is not already checked.

  3. Check the box next to the Create Several option, if it is not already checked.

  4. Click the next to Line Properties to open the Line Properties section.

  5. To set the line style, click on the existing option next to Style. Select the desired line from the list. For example, select the .1 in. Dash to create a dashed line.

  6. Click the next to Label Properties to open the Label Properties section.

  7. Click the <Click here to modify the labels> text next to Modify Labels.

  8. In the Label Position Editor dialog,

    1. Click on Primary in the Available Fields list and click Add.

    2. Click the Font button.

    3. Set the Points to 10.

    4. Click OK.

    5. In the Label Position section, select Position Along Line.

    6. Set Label Alignment On to On.

    7. Set Label Position Along to Middle.

    8. Click OK and the label properties are set for all of the lines being drawn.

  9. If you are using a digitizing tablet, move the puck over one end of the 88.30 contour. If you are using an image base map, move the cursor with the mouse over one end of the 88.30 contour. Press and hold the digitize button or left mouse button and drag the puck or cursor along the contour line from the beginning to the end. You should see a polyline drawn in the plot window.

  10. After the cursor or puck reaches the end of the line, press the ENTER key on the keyboard, double-click the left mouse button, or press the finish button on the puck to stop digitizing the line.

  11. The Enter Object Data dialog is displayed. Click in the Primary field and type 88.30, the contour level value for the line just digitized.

  12. Click OK in the Enter Object Data dialog.

  13. Click on the beginning point for the next contour line on the map.

  14. Repeat steps 9-13 for all contour lines on the map.

  15. Press the ESC key on the keyboard after you are done tracing the last contour line. This ends digitize mode.


Digitizing polylines and polygons takes a bit of practice. If you are not satisfied with the way the object looks as you are digitizing it, you can click the right mouse button to remove the last digitized vertex. If the line is beyond repair, click ESC on your keyboard to cancel digitizing, delete the line, and start over. These commands apply to both tablet digitizing and image digitizing, although you can set a puck button to act like right-clicking the mouse. See Digitizing Settings for more information on puck button settings.


Back to Assigning Labels

Next to Editing Polylines