7.0

Sketch Mode
This option is useful if you are rapidly sketching lots of separate lines
close to each other, perhaps using a drawing tablet.
When working this way you won't normally want to edit existing lines you've already drawn, but instead
draw new lines with every stroke. But as described above, if you start a draw operation on an existing
line, or on its end point, that existing line is modified. So when sketching you may inadvertently modify
existing lines with your strokes, instead of drawing new lines on top as you'd intended.
To overcome this problem, turn on sketch mode. Now if you hold the mouse pointer over an existing
line, or end point, you'll notice that there is a short pause before the mouse pointer changes to indicate
that the line will be edited or extended. This pause means you can still edit existing lines if you want, but
you won't do so unintentionally when you actually mean to sketch new lines.
Trace mode
Trace mode helps you to draw lines which follow visible edges in photo images. For example you can
use it to help you draw around a building or other object in a photo, that you want to cut out.
For most photos it's best to turn smoothing down from the default value, so that the line more closely
follows complex edges with less smoothing of the line as you draw. You can always adjust the smoothing
after drawing the line, if required.
Trace mode on/off
Turn on trace mode using the toggle button on the infobar. Draw with
the Freehand tool over a photo and you should see that the line tries to
follow edges in the image.
You can also turn trace mode on and off while you are actively drawing a line, by pressing the T
key. The mouse pointer changes to indicate whether trace mode is on or off. This allows you, for
example, to turn off trace mode when you are drawing over a complex part of an image where there is no
obvious edge for trace mode to follow.
Commit points
You'll often notice as you draw along an edge in a photo that sometimes the last few pixels of the line
you've drawn will 'jump' around as it searches for different routes. When there is more than one possible
route, move the mouse pointer around and see the edge jump between them. You can 'commit' the edge
at any time by pressing the space bar
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