how do i overlay two clips (watch video)

[Sebastien Gravel]

The only way I can think of is stack up all the shots one on top of the other with a few seconds apart for each person and then use mask to isolate each copy for the background.

That’s my suggestion…

[Neil Moxham]

If the two images dont cross in front of each other then simply find a good seam and cut a mask line along it to expose the other clip underneath. this way the other shot will be there. I have done this a few times and it works well. watch your shadows though.
its more complicated and time consuming to have object cross in front of each other but its do-able in vegas.
Zipedit

[Sebastien Gravel]

The difficulty is that there is panning of the camera. The movement makes it much harder to have accurate mask following the persons.