Wall portals in ZDoom?

I was wondering if there are many ways to create a wall portal-type effect in zdoom. What I'm trying to do is make two far-apart rooms look as if they are connected by a window. I've tried sloped portals but I just get a hall of mirrors effect.

I'm sure it's not possible in ZDoom, maybe you can use a skybox to simulate the effect, or you could bind a camera to a texture.

It's been a very long time since I touched an editor but I'm certain you could do it with a camtex lump (check the wiki) and a couple of linedefs that are nested within the wall-- about 1px away from the surface, maybe? I don't know.

Some years ago, JonnyFive played around with that idea.
http://forum.zdoom.org/viewtopic.php?t=19822

Yes, there is a way to do this. What I would do is:
-Set up two camera textures (look up how to do that on the Zdoom wiki or something)
-Have the cameras pointing outwards from each wall
-Set the wall textures to whatever you defined the camera textures as
-Set the linedef action to teleport to a destination or line in the other room, with the trigger being "player bumps".

I would whip up a little demo wad, but it's 3 AM and I don't feel like it right now. The weakness to this method is that if you want a lot of these, you have to define a lot of camera textures and it gets tedious after a while.