Transparent mirror

What materials and rendering settings would I have to use to get a transparent mirror?

What I need is a sort of glass floor that would reflect the objects placed over it (with reflection’s opacity gradually going down the further something is from the floor). Where there is no reflection I would like the floor to be completely transparent, so that an image that is being composited into the final render as a skybox of sorts is visible.

I use a plane as the floor and at this point I can only get mirroring effect when it is opaque, making it fully transparent makes the reflection transparent as well.

Can someone help?

Edit: I’m using 2.5

Set the reflectivity to %100.
There is not “only reflection” button, but you can take the reflection render pass from the floor and composite it in with a render pass taken without the floor in it.

Thanks for your help Asano.
Unfortunately it didn’t work. For some reason the reflection pass is always black.

That is curious. Post the .blend? I’ll take a look at it tonight and see what I can come up with.

Alternately you could render your image without the floor, then render the whole image with the floor (%100 reflective) then render a 3rd image after you change the materials. Change the floor to be a white shadeless material (so it is matter white) and everything else to be a black shadeless material (matte black). Then use that 3rd render as a mask to combine the two.

Hey MichalB,

I’m trying to get basically the same thing going, did you ever figure out a solution?


I remember reading a tutorial on this some time ago, I think it was called ‘product rendering in blender’.

Hey qumah,

In a search a few different results came up and none of them mention reflectivity, do you have any more specifics? Thanks for the tip, anyway.