1. took a High resolution scan of a map from 1650 and put it into Sony Vegas
2. rendered a piece of video showing a zoom out from the center of the map
3. took that piece of rendered video and put it back into Sony Vegas.
4. made two video tracks and put a copy of the rendered video on each track ,one on top of the other.
5. reversed the top track and changed it’s setting from “source alpha” to “difference”.
6. rendered the over-layed tracks.
The result was surprising. If you look at the middle of the screen while the video played you’ll notice some weird looking effects as two layers come to the middle
of the sequence where it turns black. Make sure you watch the center of the screen for the whole duration if you want to see the effect.