Creating a Matte Key for Use with 3D Effects
A matte key is an effect made up of three components:
  High-contrast image or matte
  Background image (the image that shows through the lightest part of the matte)
  Foreground image (the image that shows through the darkest part of the matte)
  For more information on Matte Key clips, see Creating a Matte Key Effect.
You can promote real-time 2D Matte Key effects (graphics imported with an alpha channel) to 3D effects and apply additional parameters, such as Shape Wipe effects, or X, Y, and Z positioning.
  You cannot promote matte keys created using the Matte Key effect from the 2D Effect Palette to a 3D matte key.
To create a matte key for use with 3D effects:
1.  Import a graphic file containing an alpha channel.
The Avid editing application creates a Matte Key clip when you import the file.
2.  Edit the Matte Key clip into your sequence as an overlay.
3.  Ensure that Render On-the-Fly is enabled (displays a check mark in the Clip menu) so you can see the matte key as you are working with it.
4.  Promote the Matte Key clip to a 3D effect as explained in Promoting 2D Effects to 3D Effects.
5.  Select Tools > Effect Editor to open the Effect Editor, and apply changes to additional parameters to achieve the effect you want.
See Also
Accessing 3D Effects in the Effects Palette
Promoting 2D Effects to 3D Effects

Some features described in Help are available only in Avid Xpress Pro or Avid Xpress DV. For more information about Avid Free DV go to
www.avid.com.