Name of a 3d photo/video effect?

Question

There is an effect sometimes used by TV broadcasters where they have a video or a photo and they have an object going behind one of the characters in the video/photo while it is infront of the other characters.

For example, if there are two characters in a photo/video. Let's call the two characters X and Y. Let's say Y is standing in the foreground and X is in the background. There is an object that goes behind Y but in front of X.

What is this effect name? And can I do it on Sony Vegas?

Answer 1

This effect is called layering. For what you want you can use an overlay effect in Sony Vegas as seen in this video:

http://www.youtube.com/watch?v=aZ75dEKiw...

Basically, X and Y need to be on separate videos. First, use the overlay effect on the video containing X and then create a video with Y in front of a green screen for your second overlay.