Importing Files with Existing Alpha Channels

If the footage you import contains an alpha channel, combustion automatically uses it to determine the layer's transparency. If there is no alpha channel in a clip or still image, combustion automatically creates a default channel. The default alpha channel has no effect on a clip's transparency. You can modify the alpha channel using Paint, a Keyer, a mask, or various channel effects.

For example, you can create an animated 3D logo in 3ds max and render it with an alpha channel. You can then import the logo into combustion and build a composite using any clip as a background for the logo.