Using video effects that work with graphic-file alpha channels

1. Choose Video Effects > Stylize > Alpha Glow to apply an Alpha Glow effect to the graphic in Video 2, open its Settings dialog box, and experiment with its settings.
The Start Color and End Color parameters set the colors of the glow.
2. Delete Alpha Glow from the Effect Controls panel, choose Video Effects > Perspective > Bevel Alpha, and drag the Bevel Alpha effect into its place.
3. Choose Video Effects > Perspective and add a Drop Shadow effect below the Bevel Alpha effect in the Effect Controls panel. Set Shadow Opacity to 70%, Distance to 10, and Softness to 40. (figure)
Some video formats may also contain alpha channels. DV cannot, but the QuickTime .mov and uncompressed .avi formats are examples of formats that can contain alpha channels. ???
4. Drag the scratches.mov clip over the logo clip in Video 2 to overlay it.
5. Drag the brown clip to Video 3 and set its Opacity parameter to 20%. Press Enter to render and play the sequence.




http://en.wikipedia.org/wiki/Rendering_(computer_graphics)