2013

Drawing Lines and Shapes 81
Trace mode
Trace mode helps you to draw lines which follow visible edges in photo images. 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.
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.
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.
You can ‘commit’ the edge at any time by pressing the
SPACE BAR when a correct
route has been found. Then continue and trace mode will find more routes between
the last commit point and the mouse pointer. Commit points are automatically added
for you every 50 screen pixels.
Cutting out objects from photos
To cut out part of a photo you can either draw an ordinary shape over the top of the
photo and then use the combine shapes operations in the
ARRANGE menu to cut the
photo with the shape (see the Shape Handling chapter (on page 135) for details).