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Using the Mask Generator

The Mask Generator is a plug-in that controls the transparency of events to be used as masks when you use events that are not grayscale. Apply the plug-in to an event (or a track) in the same way as any other plug- in: just drag-and-drop. The Mask Generator plug-in can be found in the Video FX window (from the View menu, choose Video FX).

How the Mask Generator works

The following illustration demonstrates some of the effects of the Mask Generator. The background image is the original mask. There are five ellipses on the mask: white, red, green, blue and an invisible alpha channel. Note especially the checkered ellipse in the lower left of the mask; this is the alpha channel. You can base the alpha channel on a color or define the alpha channel in a graphics program that supports alpha channel creation. Masks with alpha channels must be saved in a format that supports this method of transparency, such as PNG or TGA. As in this example, the alpha channel may be invisible in the actual mask.

Mask track (Parent)

Masked track (Child)

Luminance

Blue

CHP. 14

USING VIDEO FX, COMPOSITING, AND MASKS