VF extensions mean you are using Vegas Movie Studio. Nesting projects is a feature only found in Vegas Pro.
David's method will result in a graphic with a 255 green background that you can then chroma-key out when dropped into the timeline. This can be as good as a true alpha channel if you render it out to an uncompressed or lossless codec. If you render to a lossy, low color sampling codec, then it won't be as clean and you could run into issues with semi-transparent areas and parts with fine lines/details.
By default the Vegas timeline has a transparent background, so as long as you don't drop a 100% opaque solid underneath your transparent graphics, and you render it out using as uncompressed or with a codec that supports a built-in alpha channel (Quicktime Animation) then you will end up with a solid video file that has a built-in alpha channel.
However, since you're using Vegas MS and not Pro, I am not sure how it handles files that have an alpha channel (or if it will let you export to an alpha channel capable codec), in which case it would be better to use David's method.
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08-11-2012 03:52 AM
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