OK Buddy, I decompiled your map so I can see how your areaportals are set, and I see the flaw in your thinking.
I think a better name for areaportals would be "smart walls" because most of the time they act like walls, sealing off the part of the world you dont want rendered. The beauty of the areaportal is that is culls the rendering. Which means
it will only render outside the areaportal if it's in the player's line of sight.
Here's an example of how the culling works.
Take a look at this door way with areaportal in game.
Now, here it is in game with wireframe set to 3. The main thing to notice is that the areas to the left and right of the door (the areas I can't see) aren't rendered.
When you're setting these up, you should turn off all things that aren't world geometery. All we want to see are the things that actually block vis, like sky, world brushes etc. So go to your visgroups and turn off the following:
- displacements
- funcdetail
- props
- tools brushes (player clips, hints and triggers etc)
- water
Now, you are looking at the nuts n bolts of the level.... where the level is being "split" up (or isn't).
Here is a picture of the doorway in hammer like stated above. You can see the nodraw brushes are connected to the skybox. The wood is just plain brushes and the areaportal is touching world geometry (the wood) all the way around perfectly on 4 sides They (the nodraw brush and touching skybox brush) make a solid wall, entirely dividing one part of the level from the next, with the exception of the areaportal.
So, the concept of the areaportal is to aid in keeping things from being rendered that aren't in sight of the player by using the cull method.
Black = world geometry/sky
blue = areaportals
green = blocked line of sight(world effectively cut off)
red = ublocked line of sight (world not cut off, everything rendered)
This is a way to get your world to split, which can also create a natural choke point in the map.
In this picture the two areportals see into eachothers areas so nothing really gets culled, everything gets rendered.
Here's an example of a simple, practicle layout using geometry and areaportals to "turn off" areas not in the line of sight.
In that set up, only 2 or three sections can bee seen at one time.
All the blocked areas are sealed off so the game knows that those areas are now out of bounds for your line of sight.and now the areaportals now effectively cull.
Here's how valve does it:
I hope that helps explains the mystery! good luck!
....Here's some good reading
http://rvanhoorn.ruhosting.nl/optimizat ... reaportals
