Black Mirror - 3D Cutaway

[Anonymous]

Hi all.

I have stumbled upon something which I haven't seen before - mainly due to not having this composition before.

I am doing a visual of a WC (exciting I know!), and to show it well I am using a 3D Cutaway, as you can see in the attached file below. The issue is the mirror you can see on the wall. It is reflecting pure black. I have changed the ray threshold to the relevant numbers to increase reflection but this has not worked. It is as if the mirror is reflecting a black environment. However this can't be the case as you can see the White environment in the opening in the ceiling in the top right of the image.

The second image I have attached (without the 3D Cutaway) shows that the mirror does reflect correctly when the cutaway is not used.

So, cutting to the chase, does anybody know why the mirror reflects only black when it is facing a 3D cutaway, when the environment is clearly white?

Thanks!
Tom

[Erwin Edel]

If you cut away the wall, it will reflect the 'background', so if you use a physical sky, it would reflect that, it looks like you have no background set up or a solid black background.

You could fake a reflection with a reflection channel in the surface settings, maybe.

[Anonymous]

Thats what I thought.

The confusing part for me is that the 'background' can be seen as white in the small oepning in the top right of the first image. If it were the case that the 'Background' for whatever reason was a different colour (black in the case of the mirror), surely it would show as that colour in the opening?

Having said that, I'll have a play with the settings and see if it changes anything.

[Anonymous]

Ok, you were correct! In the cinerender settings I did not have 'sky' turned on.

Now I just need to adjust other settings at it has massively over exposed the image.

[Erwin Edel]

https://helpcenter.graphisoft.com/guides/archicad-22/archicad-22-reference-guide/user-interface-refe...

This channel is what I was thinking would be an easy fix.

Edit: scroll down for 'exclusive' option, it will only show the channel where no actual reflections are shown. So it can be a sort of 'override' for situations like this one.