Adobe After Effects - Manual (Page 594)

Preview
Blending Matte
Final Output
Each grain effect is applied with default settings and is displayed in Preview viewing mode, which has a preview region framed by a white border
and centered on the image. The preview region displays the results of the grain effect on a portion of your image, for speed and comparison
purposes. The grain effects are almost fully automatic but also offer many controls to achieve precise results. You can also selectively apply the
grain effects to portions of your image using the extensive Blend With Original features provided with each effect.
1. Select the layer, and choose Effect > Noise & Grain > [effect].
2. Choose a viewing method from the Viewing Mode control in the Effect Controls panel:
Displays the current settings of the applied effect in a 200x200-pixel area.
Shows the current color matte or mask, or the combination of both, which results from the current settings of the Blend
With Original controls group.
Renders the full active frame, using the current settings of the effect.
3. Adjust the controls for the effect in the Effect Controls panel.
The preview region in the Composition panel reflects any changes you make.
4. Choose Final Output from the Viewing Mode control.
Apply a grain effect to a selected area
The Blend With Original controls group lets you precisely apply a grain effect to a particular area of an image by masking and matting the desired
area. You can choose between two selection techniques or use a combination of both:
Color Matching
Excludes any area of the image that matches a selected color. By inverting the matte, you can also selectively process such an area.
Masking Layer
Uses any layer in the current composition as a mask to selectively process or exclude an area of the current layer or track.
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.
2. Do any of the following in the Effect Controls panel:
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.
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