In a similar way to fake bridges, I'm trying to make an invisible door for vanilla/limit removing ports. I tried making a self referencing sector, but projectiles pass through them and enemies can see you from the other side. I'm following an example from Alien Vendetta MAP25: Notice that the ceiling of the invisible sector isn't bleeding   So I tried to do the same thing on my map, opened that map on DB and tried to do the exact same thing, but apparently I'm not doing something right, because I can see the ceiling of the invisible door: Can somebody please tell me how to do a PERFECTLY invisible door?