Drawing your first lines

Drawing options are available from the tool bar and extended options are in the Context Menu > Draw > Etc (remember: right click pulls up a context specific menu.)  Here under Draw you’ll find Pencil, Rectangle, Circle, and Measurement tools.

Line and Pencil Tools
Line and Pencil Tools

Drawing Lines is useful for mapping linear features like roads and paths, obviously.  Roads and paths typically join up in networks. Lines can be styled and there are a range of default line styles available that cover many basic requirements.

Getting lines to join up correctly is not easy by eye.  Setting Edit > Live Layer Options > When drawing, snap vertices to > will resolve almost all the circumstances you are likely to encounter!

To draw lines there are 2 basic options, the :

  1. line tool (from the toolbar) click the start and each vertex – useful for straight features
  2. pencil tool (context menu only) click and draw – useful for wiggly features – check the image on the right where we’ve cheated and styled the lines to make them look nice

Note that each tool behaves slightly differently.  Clicking each vertex with the Line Tool allows you to position the next vertex reasonably accurately.  You can correct errors one at a time using the back space as you click. If you make a hash of your line, simply press Esc(ape) to start again. To finish your line, click the last position and drag the pointer away and right click. The line is terminated at the previous left click and you will be prompted to:

  1. chose a line Style (we’ll learn how to make your own in a bit)
  2. change the Display Label or Unique Id
  3. Modify the Data tab (More later)
  4. Select from a range of Actions (More later)

If it looks terrible at this stage, you can still remove ugliness quickly with the keyboard combination CTRL+Z. Many times,  it is a great deal easier to start a fresh line or polygon than to try and edit a clumsily drawn one.

The Pencil Tool is slightly different, as you have to hold the pencil down and it offers no incremental deletion option. To finish your line, simply release the mouse exactly where you want it terminated.   When the Pencil Tool is terminated you get exactly the same tabbed options as the Line Tool.  That’s because Pencil Lines are saved as a Line type.

Because even apparently curved
lines are made up of straight line segments, you may wish to alter the spacing of the
vertices to create a smoother pencil line. Go to File – System set up – Preferences –
Miscellaneous and adjust the value of Spacing of vertices in pixels for the pencil tool.

Curved lines are made up of straight line segments, so you may need to alter the spacing of the vertices to create a smoother pencil line.  File > System set up > Preferences > Miscellaneous and set Spacing of vertices in pixels for the pencil tool.

Nota Bene

Remember to chose your digitising scale appropriately.  Drawing lines at 1:50k will make your features appear to be several metres wide – fine if this is going to be the final presentation scale. Zoom in to 1:10k and your beautiful networks start look badly drawn, with gaps appearing at junctions and jagged lines.  However digitising at 1:10k or below will take a lot longer, so you may need to compromise depending on the accuracy and precision required.

Polygons appear to form between the lines in such networks, don’t go crazy trying to click an object which doesn’t actually exist.

Objects in the Live Layer have tell tale blue dots which will come in handy when you want to modify / edit a feature.

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