refraction and multi/sub-object material

[Mnietek2707]

Something is wrong when material with refraction is used in 2 different slots of multi/sub-object material.
Besides that there is a problem with "show map on back" switch in bitmap node.
Below images (CPU and GPU mode) and test scene.


Scene: glass problem.zip

V-Ray 5, max 2020

[nikoleta.garkova]

Hi Mnietek2707

Thank you for providing the files - this is not a matter of Multi-sub, however, we're aware of similar issues with Fog color other than white used in the Coat slot of a VRayBlendMtl and I'm afraid they are indeed producing different results in CPU vs GPU. It is logged into our internal bug-tracking system under VGPU-703; I'll bump its priority additionally and will let you know when there are any updates in this regard. You might want to either use CPU for this particular scene or, if applicable, avoid using Fog color.

I could reproduce The 'Show map on back' issue you are describing and it is now logged under VGPU-5289 - will keep you posted.

Thanks for the pointers - appreciate your patience