Adobe 65008009 - After Effects CS4 Using Manual page 526

Last updated 12/21/2009
When any grain effect is first applied, the Amount value of the Blend With Original controls group is set to 0%; this
value determines the percentage of blending between the original image and the processed version. At 0%, no blending
occurs and the selected effect is applied to the entire image at full strength; at 100%, white areas of the blending matte
are unchanged from the original image.
Any mask or matte works in a similar way: The white pixels in it exclude that area of the original image from processing
by the grain effect; the black pixels process normally. At 100% Amount, the white areas fully blend with the original so
that they are completely excluded from the processing. This behavior remains true when the match is inverted.
Regardless of the Amount value, the black areas of the matte or mask are always processed. The Amount slider affects
only the areas under the white pixels in the matte or mask. It affects only how each grain effect treats the white areas
of the matte or mask.
1 Apply a grain effect to the image.
Do any of the following in the Effect Controls panel:
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• To create a matte around the area to which you want to apply or exclude the grain effect, use the Color Matching
controls in the Blend With Original controls group.
• To mask the current layer with another layer or track, use the Masking Layer controls.
3 Adjust the Blur Matte value to soften the matte and to produce a softer transition between the affected and
unaffected areas of the image.
If you're using both a color matte and a layer mask, choose one of the following from the Combine Match And
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Mask Using menu:
Makes the matte white wherever either the mask or the color match is white.
Screen
Makes the matte white where both of the inputs are white.
Multiply
Reduce the Amount value to let more of the original image show through the grain.
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Choose Final Output from the Viewing Mode control.
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Generate a color-matching matte
When a grain effect is first applied, a neutral gray color is used to generate a default color-matching matte, so that in
most images a visible matte appears. The Color Matching group of controls uses color matching to precisely define a
matte. The matte isolates portions of the image where the layer that uses the grain effect is blended with the input.
Apply a grain effect to the image.
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To select a color to exclude from or restrict to the effect, do one of the following adjacent to the Matching Color
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control in the Blend With Original and Color Matching controls groups:
• Click the color swatch and select a color in the Color Picker dialog box.
• Click the eyedropper
3 Do one of the following:
• To prevent the grain effect from affecting the selected color, make sure that the Invert Match control is deselected.
• To restrict the grain effect to the selected color, leaving the rest of the image unaffected, select Invert Match.
If you want to exclude colors that are similar to the matching color, increase the Matching Tolerance value, which
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sets a threshold for color matching. As the value increases, the matte includes pixels with colors increasingly
different from the matching color.
5 Choose an option from the Match Color Using control if you want to change the default criterion (RGB) used to
determine that a color is similar to the matching color.
and click a color anywhere on the screen.
USING AFTER EFFECTS CS4
Effects and animation presets
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