I was wondering if Source has reached the technical capacity to do this:

[yt:7hsydy6c]http://www.youtube.com/watch?v=6eJC5zYZ9JE[/yt:7hsydy6c]

Any idea? I'd love to do this sorta effect in a few maps. I just had a flash of this effect while mapping with world portals.

The only Source game to use this is a game in GMod Tower that I'm aware of; I also made a super-hacky way in a mod. Wouldn't really recommend it unless you're making considerable modifications to the player.