Ok, well here’s an impossible triangle that I made in about 30 min.
It is of course impossible, since blender can’t do stuff like this, But I found a way…
Tell me what you think! 
Argh! i can never figure out how you do them! well i’ve never actually tried.
BMD
THAT IS 2D…MUWHAHAHAHA 
(j/k just guessing)
I think each edge/face is a seperate L shaped piece, which are aligned one behind the other, facing the camera.
Love this kind of modeling, could do with a bit more light, but that might be due to my monitor.
Sonix.
You have to do that with an orthogonal camera, right? if you move the point of view at all you’d see that one corner doesn’t actually join up.
I’ll also put a dollar down and say that you applied the texture with a “window” mapping. You’d also have to use a parallel lamp (does the sun lamp do this?)
OK, I’ll stop now. I was the kid that kept bugging the magician to tell me how the trick was done 
I did something like this a year or two ago…
Call it triangle ABC, A being at the top, B bottom right, and C bottom left…
AB is going away from the camera while BC is closer to the camera, and both are connected by AC…
Is that how you did it?
Side View:
/\
You’re all wrong!
I hate kids like that. :< :-? 
NEVER give away a trick! EVER! :< :x :-? heh.
I know, you made an L object but then 45 degrees, and another object that is \ and then place it behind that L 45 degree, and place the camera so, that it looks like it’s one object.
Dang. I’m gonna have to try to replicate this myself tonight then.
nope.
Cool!
My guess: It is a flat mesh, UV mapped, or with 3 like material indices, with slight adjustments of HSV.
NO! It’s a 3d object.
Ha!
Got it!
Did you also find that it was necessary to add the texture?
COPYCAT!
no, I didn’t find it necessary. But mine looks more pleasant that way.
zinvert?
Nope.
Hey Lemmy, it’s kind of fun when you know the secret