Alright, I am working on a map that while isn't huge, it is long and somewhat narrow. It basically is a twisting hallway with brief areas of interest centered around a medium sized room. I have two problems, lighting and where on earth to place an areaportal. My lighting issue is that there needs to a number of sources and I can't have too many shaders (not that I'm too good at doing those LOL). I would accept any suggestions there. The area portal problem is that the location is from the Star Wars movies and I had noticed as the characters had moved throught the scenes from the doors were open (I know this was for action purposes from the point of directing a film) and so I was about to do the same. Now that wouldn't let me have a good place to put and areaportal--the hall is a straight shot to one side of the map (West as I have created the map). While elevation has changed, if you stand and look westward you can see the far end, albeit at a good distance. I'd just stick something in the way--but I want to be true to the movie and you can see no obstruction down the corridor.
I must be missing something, you don't exactly need shaders to do lighting in a level. In gtkradiant there's a light entitiy you use. As for the area portal, elaborate on WHY you need an area portal.
And, you CAN make invisible area portals.