Draw tool is an auxiliary tool for the snapping mechanism. When snapping is enabled, the cursor will snap to lines and points on the lines the same way it snaps to edges and points on the edges.
The lines can be drawn on objects only. Right now you can't draw on the ground, unfortunately.
To draw a line, click
LMB at the point where it should start, then click at the point where it should end, or click
RMB to cancel the drawing.
RMB at an existing line to delete it. If you click
RMB at an intersection point of multiple lines, all those lines will be deleted.
If the line crosses the border(s) between different parts within the object or crosses any other line(s), it will be automatically split into multiple segments at the points of intersection.
Snapping to angles
In addition to snapping to points and lines, the draw tool also supports snapping to angles. This mode is activated by holding
Shift. If the line you are drawing intersects another line or edge, it can snap to a given angle with that line.
You can adjust the desired snapping angle using
Scroll Wheel while holding
Shift. The possible range of values is 0 - 90 degrees with a step of 1, 5 or 15 degrees. You can set the step you like in the game settings inside the main menu.
Note, that snapping to 0° and 90° angles are always active. 0° is useful for extending an existing line.