How to assign multiple materials to one mesh?

[popsomoa]

Hi,

I've only started to learn v-ray so sorry if this is a very basic question, but how do I assign multiple materials to one mesh? For example — when I create a cube with one red material on all faces it renders a perfectly fine red cube, but If I continue to assign another blue material to just one face the entire object renders black. I would expect the cube to be completely red except for one blue face. I'm using the standard Blender materials tab and the 'Assign' button to assign different materials. What is the correct way to do this?

Thanks for your help.

[JuhaW]

Thats the correct way to do material assigning. Could you share the .blend file ?

[popsomoa]

Here is my blend file, I have 3 cubes, the one in the middle with one red face is the one giving me trouble.

cube.blend.zip

[JuhaW]

It renders fine, maybe something to do with your Vray version or exporter.

[popsomoa]

Hmm, interesting. Thanks for checking JuhaW.

I'm too new to V-ray to know if it's a bug or my settings, but if anybody else has ideas please let me know.

I'm using Blender V-ray build 2.73, V-ray Standalone 3.20.03 on a Mac (Yosemite) and I've pressed 'Update Exporter' today in Blender so I think all my versions are up to date.

And this is the output of the blend file:

[popsomoa]

I downloaded the latest nightly Blender build 2.76 and it works as expected now.