Autodesk Combustion 4 Fundamentals Courseware

Using Alpha Channels

Lesson 24

In this lesson, use alpha channels to define which parts of footage are visible through the use of mattes and stencils.

Overview

An alpha channel is a grayscale version of an image that defines its transparency. This channel allows you to see the layers behind a particular layer in a composite. You can apply an alpha channel to a layer in four ways: by using the Set Matte operator, by creating a Stencil Layer, by preserving the alpha channel for the layer or by using masks.

In this lesson:

• Create a matte for a layer using the alpha channel of an image.

• Animate a matte’s position and texture.

• Create a matte using ...