Idea for a visual mod if anyone wants to try it.
This will never work in maps with varied lighting. 
Orange portal in dark area.
Blue portal in area with red light.
White light shines through both portals?
I had the same idea of lighting trough portals, for a dark room, where you have to light your way with a portal.
I'm new to mapping, it's the first time i work with hammer. When i understand how difficult it was to do, i give up the idea, but at this point my reflexion was also to use a dynamic_light with a simple configuration :
- you can only fire blue portals
- an emancipation grid at the entrance of a small room with a white and uniform light, and an orange portal in it.
- the dark room, the only place where you have to put portal detector and move the light in front of the portal.
Coult it be possible?
ps : oh, i'm sorry for my mistakes in english, it's not my native language...
I'm new to mapping, it's the first time i work with hammer. When i understand how difficult it was to do, i give up the idea, but at this point my reflexion was also to use a dynamic_light with a simple configuration :
- you can only fire blue portals
- an emancipation grid at the entrance of a small room with a white and uniform light, and an orange portal in it.
- the dark room, the only place where you have to put portal detector and move the light in front of the portal.
Coult it be possible?
ps : oh, i'm sorry for my mistakes in english, it's not my native language...
You know, on a puzzle where you can only fire 1 portal might actually be capable of making use of this idea.
For example if you have a dark room in which all the walls except for 1 is metal, then you could place a spot light there (off by default) and a portal detector.
Then have the opposite portal (orange) under a very noticeable spot light then you could have it so that when the person fires the blue portal onto the portal detector then turn the spot light on, lighting up the room.
This could easily give the illusion of lighting the room up.
You might also want to add a secondary light in the center of the room and turn that on with the spot light, so you can simulate the light entering the room and then bouncing around the entire room. Like if you aim a flash light to your ceiling, it lights the entire room up.
Hmm, the notion of using fixed-location portals with fixed-location lighting is a promising one. I'm reminded of the test chamber(s) where there was a rotating ASHPD that shot out portals at 90 degree angles as it rotated around. Being able to control portal location thusly would simplify light entity placement.
There is only one problem with having the pre-set placement of lights/portals. Not that it wouldn't work when you needed it to, it's pretty obvious it can be done (I even did it [albeit a very complicated way] in attempt to make it global) but, if it ONLY works in pre-set areas, the player may get confused and try to use it in areas where you haven't set it up to work and then get frustrated that the feature only works sometimes.
Think about "Sometimes you can fire portals on concrete floors, sometimes you can't"
So, if you were to implement this, you'd need a way to clearly define when this will work and when it won't, so player's won't get confused.
What would explain why the whole fake lighting thing wouldn't work on a global scale. I see.
What I was describing earlier though, would have to do with puzzles that were so simple that only a single solution was possible, which would narrow the puzzle down into what you initially expected. Which would be the person placing the portal on top of your trigger, and no where else.