Ok, we were runnig a small experiment using _blocksize 0 in the worldspawn. My goal was to make a complex leaf node that kind of stretched outside of the map but you could still see it through the sky. I tested this idea with something far simpler outside loop and it worked fine but when i tried something complex it seemed not to. Because _blocksize is 0 and I have no portal lines being drawn whatsoever other than by structural brushes, there SHOULD be only one leaf node in this entire map. Because there is only one leaf node, players when standing in that leaf node should have a PVS set of one leaf node, and should be able to see the entire map. There are areas that extend out of view but they are covered in sky so they should be viewable.

Keep in mind there are no portal lines in this map other than the structural brushes themselves, and the entire map is connected as one piece, just a 50 sided room or so.

Here is an overview of the setup in radiant . If you look at the upper right picture there is small passageway connecting the main middle area to the outside halo.

http://i50.photobucket.com/albums/f317/acroso/sdfsd3.jpg


Here is a another pic of the small passage way. It was enlarged a bit in this pic because i tried the compile over again but it did the same thing.

http://i50.photobucket.com/albums/f317/acroso/sdfsd7.jpg

To my dismay, after compiling, there were portal lines??? why are they there? Here they are on the 2d grid

http://i50.photobucket.com/albums/f317/acroso/sdfsd4.jpg

Here are the portal lines on the 3d grid

http://i50.photobucket.com/albums/f317/acroso/sdfsd5.jpg

Here I am standing out in the outside halo with detail brushes filtered so you can see there shouldn't be any portal lines being placed in those hallways.
http://i50.photobucket.com/albums/f317/acroso/sdfsd6.jpg

Here is one last picture. This one is me standing in game looking at the little passageway to the outer halo that should be connecting the entire thing as one solid leaf node. Instead you only see a small section of the halo, and it stops in accordance to the random portal lines that the compiler inserted with telling the compiler to insert (as seen above.)
http://i50.photobucket.com/albums/f317/acroso/shot0111.jpg


So we have no hints, no subtle hints, no blocksize automatic lines being drawn, no area portals or anything, but we're still getting portal lines drawn in by the compiler.

Why is that and is there anyway to stop the compiler from doing that? 

i'm not an experienced q3 engine mapper, but it seems like you've got a lot of structural brushes in there, like the sky and caulk... those would cause the world to be split into multiple leafs I would think... leafs have to be convex.

Seems like to make one leaf you'd have to have one giant structural box room, and everything else inside it should be detail.

Oh, and in the future please post this sort of thing in the Mapping Help thread. 

If you don't really want/need things broken up in a PVS, why even vis the map? That's all vis does. One of my last Quake3 maps was released without vising it, simply because it was a large open box basically, and even if it was attempted to be split up, every part of it was visible from any other part, so the 24 hour vis time was a waste of effort.

And after just examining your pictures, I don't understand why you're building a small skybox around your main area, but then building a 'connecting hall' to the other ring thing that, if I understand correctly, you want to see from your main area. Why not simply make a single huge box around everything (main area and ring) as your sky? 

Use the _skybox entity, a q3map2 compiler entity which is designed to do pretty much exactly what you're trying to achieve.

There seems to be a lot of people asking questions in curious places at the moment, you'd be better off asking Quake 3 questions at http://www.quake3world.com/forum/viewforum.php?f=10 which incidentally is currently infested with questions about mapping for classic Quake... 

But isn't this the classic autocutting that viz makes in most engines - dividing the map into quarters across the 0,0,0 in the world?

I think it adds secondary slices after a certain distance as well.

It's not too useful for most modern maps to know this (since their size means they'll always cross one of the auto-divisions) but for smaller maps it can save some vis time by moving your map entire into the corner of the build space rather than having it neatly divided into eight by the world 0,0,0.

Don't know if that'll help - sounds like Scampie and Shallow already answered the problem pretty concisely.