Wrong or inverted normal map iff using a UVW Randomizer map

[LautaroVogel]

Hi! We just realized some of the materials in our library looked odd so we started doing some tests and it turns out it was the normals, but all the settings, gamma, green channels, etc seemed to be correctly setup. We also found a note here (https://docs.chaosgroup.com/display/VMAX/VRayNormalMap) saying that the order of triplanars and normal maps could have an impact on the look of it but that really didn't make a difference in our case.

The only thing that seems to make a difference is when a UVW Randomizer map is plugged in (it seems to invert both the red and the green channels). Please see attached. Again, if not using this map, then the order of triplanar vs normal maps doesn't make a difference, it works fine either way.
I couldn't find anything about it online so not sure if it's a bug or something we are doing wrong.

P.S.: this is the tree we like to use in our materials as it is really simple but also allows our artists to quickly change triplanar size for all maps or introduce some randomization if needed. Note that the UVW Randomizer map is not really doing anything as all checkboxes are by default.
Any help would be much appreciated. Thanks!

Lautaro

3dsmax 2021
VRay 5 update 1.2
Windows 10

[^Lele^]

We'd surely need a setup in hand to see what is wrong.
Would you share that plane scene with Support?

[LautaroVogel]

We'd surely need a setup in hand to see what is wrong.
Would you share that plane scene with Support?

Thanks for the quick response lele Sure thing, I'll post it here in a bit once I get to the office.
In the meantime, it really is literally just what you see in the screengrab: a plane, a spherical light and a simple mtl with a normal map (don't even need the rest of the maps). All render settings and such are by default so hopefully, it should be quite quick and easy to check if the UVWRandomizer does or does not change the look of the normals of materials in any scene of yours too? Could you please confirm that this is not the intended behaviour?

Should I upload the scene here or send it to an email address?
Many thanks,
Lautaro

[^Lele^]

Lautaro, hello.
I asked you to send support@chaosgroup.com the very scene because i was testing a similar setup from our matlib (take the bricks there), and i can't get it to misbehave.
So it could be a problem with the specific setup, or a non-obvious bug with us.

[LautaroVogel]

Ah perfect, thanks Lele.
I've just sent the scene over (ticket number 339-935-3049), let me know if you need anything else or come across the solution please

[LautaroVogel]

Hi lele , just following up to see if you managed to reproduce the issue on your end? It seems to be related to the rotation parameter only, and when all the randomization checkboxes are unchecked. As soon as I set the rotation From 0 To 0 the normals look good.
Cheers
Lautaro