New types of fizzlers : doable?
But I'm still wondering what would be the purpose of blocking blue or red portals only. Aren't this two exactly the same ?
no
there are a few flinging puzzels where when you place a portal mid fling you have to use the right one, it doesn't matter which one, as long as it corresponds to one you have already placed. a re/blue only fizzler would force you to start with the right coloured portal, adding a teensy bit more of a challenge, but not much more really.
Oh, I see.
Sounds kinda frustrating to me.
I don't see how allowing only 1 type of portal through a fizzler would be interesting/fun/etc. seeing as both portals have the same function.
there are a few flinging puzzels where when you place a portal mid fling you have to use the right one, it doesn't matter which one, as long as it corresponds to one you have already placed. a re/blue only fizzler would force you to start with the right coloured portal, adding a teensy bit more of a challenge, but not much more really.
Its equivalent to making everyone walk starting with their right foot. Not a useful distinction IMO.
I am only mildly interested in the other forms of fizzlers; for these reasons:
1) Stuff can go through; person dies if they do. The new facility map has one of these, actually. I pushed my cube through it and knocked the turret over on the other side. . .then I accidentally knocked the cube out of my hand while turning around so the cube was on the other side where there were no portable surfaces.
End result: an unreachable cube, with no easy way for the mapper to detect it. Time to restart the level. . . and if there WERE portable surfaces over there, then the killing part didnt really mean a whole lot, now did it? Used badly, this is a whole new nightmare for mappers. . .so its got a low ROI, IMO.
2) Portals can go through; people/cubes cant. Not complaing about that one at all; except that its already present. We already have that in two ways; that mesh texture (I forget the name), and the Combine energy field (as was already mentioned). Both are acceptable and easily identifiable, and one has the advantage that you can instantly turn it on/off. Lots of maps use one or both already, so its really not "new". Heck, its even a fair assumptin that glados can possibly get ahold of the combine tech, since its already established they are in the same universe.
Its not like walking on the right foot, because when walking you can do a double step and end up walking with the other foot first, if you construct your puzzle right you have to do a whole load of portal placements on after the other where if you use the wrong portal by mistake then you have to start again. It may not be a huge game mechanic but don't brush it off It could make some very interesting complicated puzzles
Actually, by forcing the player to use a certain portal for the set up, it makes the puzzle easier.
Maybe I am still missing what you are saying. 
All of what you just said seemed to ALREADY be true, except that I currently get the right to determine which portal I start off with when I do that "whole load of portal placements where if you use the wrong portal by mistake you have to start again". You didnt add any complexity. . .it was already there if the puzzles needed a lot of portals.
So no, it just seems needlessly restrictive to me; exactly like saying we all have to start with the right foot. Hye you yourself even said:
"would force you to start with the right coloured portal,"
(replace "right colored portal" with "right foot", please. . .)
The grate texture already in the game allows portal shots to go through but blocks players and cubes.
I got one-portal walls working in this thread: post9419.html#9419
Don't know if anyone cares about that. You could easily zone off an entire section to be orange/blue only with the func_portal_detector - you'd just need some way of showing that a section is one or the other (lighting? custom overlay?). Is there anything in the source engine equivalent to the Unreal Engine's "special lit" texturing? You could set a wall to "special lit" which meant it would only render lighting from "special lit" lights. I guess a spotlight of some sort could do the trick.
Fizzlers would probably require a quick extension of current fizzler code and a particle redesign, neither of which I know how to do. (Sorry!)
I use a combine shield textured func_brush with solidity set to never solid, and a player clip brush surrounding it.
I guess use a trigger_hurt for the red one.