2017

To fine-tune the matte:
1 Adjust the softness borders and mask border by moving the vertices and tangents:
■ The mask border should follow the general contour of the subject as closely as possible.
■ The outer softness border should completely surround all details that you want to include in the
matte—all wispy details and edges must be within this line.
■ The inner softness border should be well within the area where softness control is needed.
When moving tangents, you can opt to have the pickers follow the tangent movement (the default
behaviour), or be independent of tangent movement. To make pickers independent of tangents, switch
to Break mode and click either picker. You can animate this behaviour. See Animating a Tracer Mask
(page 772).
NOTE If the tangents are broken, the pickers are automatically unlinked from the tangents.
2 For each pair of pickers, one requires a sample of the area outside the mask, while the other requires
a sample of the mask interior.
Place one picker outside the subject to sample values you do not want to include in the matte (for
example, a blue screen). Place the other picker within the subject for a colour value sample of an area
you do want included in the matte. Try to select areas where the colour values do not change too much
throughout the clip.
3 Click Matte or Result (Matte will provide a clearer view) to see your progress.
4 Scale the pickers by doing one of the following:
■ Select Scale edit mode, click within the picker, and drag to the left to reduce the size or to the right
to increase the size.
■ Select the picker and then drag the cursor over the Sample Size field.
5 Move the pickers around and enlarge or reduce them to interactively see how you can obtain the best
results. This will require toggling between the Front and Matte views.
GMask | 771