The Simple Mask effect allows to create a mask on the source clip and composite it with already present alpha channel. Both rectangular and elliptical shapes are supported. They can be repositioned and rotated.
The plugin can be found in the effects group “Creative Impatience”, and is called “CI Simple Mask”. To apply it, drag it over the layer, to the effects panel, or in CS6 double click.
Window type allows you to choose between rectangular and circular shapes.
Composite mode allows you to choose in what way the mask will interact with the alpha channel. By default it is set to Create, which means it will create its own alpha channel and ignore anything present. It is best suited as the first mask. Add, Subtract and Intersect will interact according to their names.
Point of origindetermines the center of the shape.
Width and Height set the width and the height of the bounding box. In case of elliptical shape they determine its both radium.
Angleallows you to rotate your shape around the point of origin.
Feather determines the amount of feather in pixels that will be applied to the inside of the shape.
Opacity sets the opacity of the mask, from 0% (totally transparent) to 100% (opaque).
Invert will toggle what is considered the inside and the outside of the shape.
Alpha falloff lets you choose between various types of feathering. Gaussianis the best, although it is also most computationally expensive. Linear is the fastest, and works reasonably well on most clips.
After clicking on the effect name, both in Premiere Pro, and in After Effects, custom controls will appear in the comp/layer window or program monitor.
The outside rectangle and rectangular handles control width and height parameters.
If an elliptical shape is chosen, the ellipse will be displayed to show the outer extent of the shape. For rectangular shape only the rectangle is shown.
Four round handles in the middle of the rectangle sides control the feather parameter. Drag any of them to the inside to modify it. Right now they might behave a bit erratically when the vignette is rotated, and also there is no limit on the feather size.
The point handle in the middle moves the vignette’s point of origin.
The slider to the left of the center is the mix slider going from 1 (100%) at the top, to 0 (0%) at the bottom.
The round handle with the line connecting it to the point of origin is used to set the shape’s rotation.
Did you find a creative application for this plugin that was not envisioned? Share the idea with the rest of us!