How can I make a one way mirror?

I’m looking for some method to make a one-way mirror in Blender.
Basically, a face which is see-through on one side, and a mirror on the other side.
I’d prefer to do this with raytracing, if at all possible, since I tend to work with mirrors quite a bit and want to make sure the reflections are able to bounce. If at all possible, I’d also like to avoid having to work with compositing, though that’s a lower priority.

Every method I’ve tried so far, including UV mapping, seems to force the mirror on both sides, even if I manage to get textures on only one.

Is there any method in Blender, or any plug-in / different rendering engine that might allow me to do this?

i tried it but I can only get mirror on one side, but can’t enable transparency on the other size,
I used 2 materials for the plane…

Then you got closer to the goal than I have. :slight_smile:
How did you achieve this…?

Try using layers; have a mirror on one a piece of glass on the other and maybe other stuff on other layers, and then compost? No clue, just kinda thinking ‘out loud’. :slight_smile:

unless its for animation why would you need this?? cant see both sides at once? and if it is for animation cant you set a key frame to swop mats as the cam switches sides?

It’s because I’m trying to make something like this:

Which would very probably be the same method as a one way mirror, as both have the same effect.

Are we talking half-mirrors ? Mirror which is semitransparent because it isn’t covered with reflective coating fully, leaving ‘holes’ in it.

Knowing that blender material could be applied to object faces and having cycles nodes available it is possible to make something a like.
It is possible to assign 2 materials on opposite sides of a single plane using compositor and BI render too.
If we take default cube and use Glass BSDF on one side and Mix of Glossy and Transparent on other, this could be something like it - glass with semitransparent mirror coat from one side. Effect can be observed in ‘real time’ as opposed to BI where you need to render images in order to see effect.
Two files to vivisect:
Blender internal

Cool concept. :slight_smile:

lol never thought of anything like that
think eppo is right you need a double sided poly:yes:

but can cheat by making the front mirror invisible to camera rays (see pic)
sont see any reason you cant add another “glass” plane over that to simulate the double sided poly, but my pain meds are kicking in an no time to test, thigns get weired from now till morning

ok wont let me upload pic:( goto object properties on the “front mirror”
down to ray visibility and untick camera

hope that helps