I created a wall which is 80 units along the y-axis and 152 units along the x-axis with the desired effect being: when portals are planted on this wall they are rotated 90 degrees from their typical position(i.e. the longest part of the portal runs horizontal rather than vertical). For some reason portals will not appear on this piece of wall.
Is there a special kind of wall that is required for this effect?

some concrete/white walls are un-portable. just use a different one, see if it works.

use a info_placement_helper

Yea, like iWork said, use and info_placement_helper rotated so the blue flag is pointing horizontal and then in the settings make sure you set use placement angles and force placement to yes, that should get you to the effect you're looking for.

Jexim wrote:
Yea, like iWork said, use and info_placement_helper rotated so the blue flag is pointing horizontal and then in the settings make sure you set use placement angles and force placement to yes, that should get you to the effect you're looking for.

Actually if you just want the rotation you should only set use angles to yes.

Thanks for your advice, people. I though the solution might be something like that, I'll try it when I get home.

But keep in mind that this will look very awkward in-game. You are taking the mechanic that portal players have learned since the beginning of the games and totally destroying it. Confusion incoming!

audiotrash wrote:
But keep in mind that this will look very awkward in-game. You are taking the mechanic that portal players have learned since the beginning of the games and totally destroying it. Confusion incoming!

Not really, it's cool to do stuff like this to make puzzle elements more difficult to maneuver (like flipping light bridges and stuff). It can definitely enhance the solution of puzzles. The only awkward thing would be if the player actually has to traverse sideways portals, then yea it's going to feel horrible...