What makes a great BTS map?
I'm making a BTS section in my map, and its the first time I'm doing it.
Any ideas on what makes a great BTS map?
Like:
-What are some good puzzles that can be incoporated in a BTS map?
-What elements should I use?
-What textures should I use?
-What are some factors to consider when making a BTS map?
Thanks! 
Lasers. I've seen some great bts maps with lasers in them, and seem to fit the style well.
Also, I wouldn't recommend too many fizzlers, because logically, some of them would be destroyed along with the rest of the test, since they run all along the walls.
Aperture Science: We do our science asbestos we can!
What I like the most when playing a BTS map is when it is designed so that there is a puzzle that is seemingly solvable "by chance".
What I mean is:
Theoretically, there aren't any puzzles in BTS areas - because they are behind the scenes and not actual test chambers and thus not even supposed to be seen by the test subject. The puzzles and their solutions seem to be there only due to lucky circustances: a conveyor belt here, a broken red paint tube there that spits out paint behind the scenes, a portalable surface above the conveyor belt - and now the red paint helps the player to outrun the conveyor belt speed and reach a new area.
The tough part is to get this illusion of purposeless into the map while at the same time hint at the puzzle elements good enough for the player to notice.
You played our Halloween map the other day. Maybe you remember the part with the turret that fires on the press of a button. Theoretically there is no puzzle in this room. It only becomes a solvable puzzle because the test subject with his/her portalgun walks in.
Thanks for the ideas! I'll credit you guys when its released, maybe I'll post some screenshots in the Showcasing Thread to let you guys see my progress and perhaps you guys can let me know what I can do to improve it 
Cheers!
There are two different things I call bts:
The one where you go through observation rooms etc and the more advanced things like the turret factory.
for both it needs to make sense the player can access an room where they're not supposed to be in.
For example: a door that leads to bts is possible; but then the player should find a key, or the door could be left open, but inside there should be something like "Remember to lock the door" or a schematic that shows who should close the door what day; with some unchecked boxes for example.
Another way to get into those rooms is by portalling out of a test chamber; in a hidden panel; something that broke; or something similiar. Observation rooms with a broken window do a very good job.
In the bts area itself I like puzzles with doors that lock and appear to be only solvable with two players; but thanks to the portalgun can be solved by one. If possible I would stay away from as many normal test elements that don't make sense in a (secured) office area. So buttons are fine; but funnels aren't.
In the offices I like small easter eggs; like in the coop maps from dlc 1; where there is a turret on one of the chairs. And of course; desks should have stuff on it. A computer or a typewriter, a mug, some boxes with papers. Just mess around until it looks realistic.
As for textures; try to stay away from the normal test chamber ones; but make sure the surfaces have correct portalablility if that's even a word
Some things to keep in mind: offices often have a lot of things in it. Some models NEED to be physics or dynamics; therefore larger rooms could become rather expensive to render. To prevent errors; add some 90 degree angles in your complex and add diagonal hint/skips. This should prevent problems.
Hope that helped:)
Thanks Lp! That helped alot and it gave me some inspiration to combine yours and Zivi's idea together to make a puzzle. ^^
Oh, and how about the "open-space" area? The one with all the tubes.
What makes a good BTS map? Your creativity and uniqueness!
Think about what Aperture would do and you build it.
I like the idea used in the coop campaign to deliver edgeless safety cubes through broken tubes. Or the part where the button delivered bombs by redirecting tubes. Finding original ways to add elements is great, and you can make equivalents to buttons like the laser that you block with the ball.
Think about what Aperture would do and you build it.
Thanks Chicken! That helped!
Thanks! But in the co-op campaign, the ball was somehow "accepted/taken away from the player" once the player goes near the laser with the ball. Any idea on how to do that?
Try using this method
mapping-help/cube-auto-snap-to-button-t7525.html