ADOBE AFTER EFFECTS 7.0
User Guide
461
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Threshold
Sets the threshold for the selected channel. The threshold is the percentage value at which everything
below or above is mapped to either white or black. For example, if a grayscale file were an altitude map with white
high and black low; the Threshold value moves the contour up or down the terrain. This is an important factor in
determining the location of the edges that Vegas strokes.
•
Pre-Blur
Smooths out the input layer before the threshold is sampled. Set this to 0 if you have a high-contrast
image and want the stroke to follow the edges very closely.
•
Tolerance
Defines how tightly the stroke conforms to the input layer. A very high setting results in sharp corners,
while very low values can make the stroking sensitive to noise.
•
Render
Specifies whether to apply Vegas to a selected contour or to all contours in the layer.
•
Selected Contour
Specifies the contour to use when Selected Contour is selected in the Render menu. Contours
are numbered from left top to bottom right; the contour with the highest point is number 1, the second highest point
is number 2, and so on.
•
Shorter Contours Have
Specifies whether shorter contours have fewer segments. By default, Vegas breaks each
contour into the same number of segments. For example, if you apply Vegas to the letter R, the outside contour may
look fine with 32 segments, but the inside contour may be almost solid. To resolve this, select Fewer Segments.
Mask/Path
Specifies the path to use for the stroke. Select the mask from the Path menu. You can use either closed or
open masks.
Segments
Specifies the number of segments used to create each stroked contour. For example, if Vegas is applied to
the word
Vegas
and Segments is set to 10, the outline of each of the letters, plus the inner contours of
e
,
g
, and
a
, are
broken into 10 segments.
Length
Determines the length of a segment’s stroke in relation to its maximum possible length. For example, if
Segments is set to 1, the maximum length of a stroke is one complete trip around the object outline. If Segments is
set to 3, the maximum length of a segment is 1/3 of the total outline, and so on.
Segment Distribution
Determines the spacing of the segments. Bunched puts the segments together like boxcars in
a train: the shorter the segment length, the shorter the overall length of the train. Even spaces the segments evenly
around the contour.
Rotation
Animates the segments around the contour. For example, to create the appearance of running lights, start
with a large number of segments set to 50% of their length, and then animate Rotation to move the lights around the
shapes.
Random Phase
Specifies that the stroke starting point is different for each contour. By default, Vegas strokes a
contour beginning at its highest point on the screen. In the event of a tie, it starts at the leftmost highest point.
Random Seed
Gives different stroke origins to two identical contours with identical settings on a layer. A random
seed is a number that is inserted into the calculation to generate a unique result. By using a different Random Seed
setting, you can make things appear different, while still using the same settings.
Blend Mode
Determines how the stroke is applied to the layer. Transparent creates the effect of Vegas on a trans-
parent background. Over places the stroke over the existing layer. Under places the stroke behind the existing layer.
Stencil uses the stroke as an alpha channel mask, filling the stroke with the pixels of the original layer.
Color
Specifies the color of the stroke, unless Stencil is chosen for Blending Mode.
Width
Specifies the width of the stroke in pixels. Fractional values are supported.
Hardness
Determines how sharp or blurry the edges of the stroke are. A value of 1 creates a slight blur; a value of 0.0
blurs the line so that few solid areas of color remain.
Start, End Opacity
Specify the opacity at the beginning or end of the stroke.
Summary of Contents for AFTER EFFECTS 7.0
Page 1: ...Chapter 1 User Guide...
