Problem with displaying of VRayOverrideMtl

[svetlozar.draganov]

Something definitely going on but we are able to reproduce this behavior from scratch.
The 2015 scene you shared indeed doesn't work on 2016 but when we try to replicate the same shading network on 2015 and then open it on 2016 it works as expected.
Is there a chance to explain us in details how the scene was created, what V-Ray and 3DSMax version and service packs are used etc.

[goeher]

Max 2015 Product version 17 SP3 commercial
VRay Adv 3.20.02

Max 2016 Product version 18 SP1 commercial (but I tested this with the new SP2 - situation is this same...)
VRay Adv 3.20.03

Creating of the scene robo2015.max:

1. Create the "Right" box
2. Convert to poly
3. Make the base material with some texture [simple base material (no override)]
4. Assign material to poly
5. UVW Map (Box)
6. Duplicate the poly as the "Left" box
7. Duplicate the base material and change name to [simple base material]
8. Assign this material to "Left" box
9. Convert [simple base material] to VRayOverrideMtl [our override material] and add some simple VRayMtl as GI material
10. In "Shaded" viewport command Materials/Realistic Materials with Maps

That's all

But I think, problem is in 2016, where by time of convertion to VRayOverrideMtl is maked some "hodgepodge" with UVW coordinates, but only these used for displaying in viewport, because in render all is ok.
Is it other set of UVW coordinates used just for generic display in viewport and separated set of UVW coordinates used for render?

Best Regards

goeher

[Zdravko.Keremidchiev]

Unfortunately we didn't manage to reproducing the issue by following your steps. Could you try the scene I created on your max 2016 Preview_view.zip

[goeher]

It is strange, but this file is opening with correct preview and, when I am making "Shaded materials with maps" or "Realistic materials with maps", at once box with overrided material is going to be grey...
This same situation was when computer was working on Windows 8 and now with Windows 10 (in mid-time I was making reinstalation of Max - it was not giving some change...). Some idea?

[Zdravko.Keremidchiev]

We found that the "Shaded materials with maps" option disables the "Show Shaded Material in Viewport" option of the Base material and enables it for the GI one instead. We made a note about this.
For now you need to go to the Base material shaders and enable its "Show Shaded Material in Viewport" option.

[goeher]

Then solution of this problem is so simple that even a brilliant... Thank You for solving the problem!!!

Best Regards

goeher