Normal maps in triplanar projection

[greymiura]

This seems to be well known issue, but although I found a lot of discussions about this topic in the different forum sections, I couldn't find a definite answer to the question if there's a working setup for the C4D version of V-Ray to use normal maps in triplanar mode.

It seems that V-Ray is using the actual UV vectors as defined in the UV layout rather than the rotated UV vectors after the triplanar projection is applied to calculate the resulting surface normal, which doesn't make any sense to me.

I even tried some different shader setups (VRayBitmap inside Triplanar inside VRayNormalMap / VRayBitmap inside C4D-Filter to invert Green inside Triplanar / C4D-Bitmap inside C4D-Filter inside Triplanar), but all with the same result.

Is there a way to get this working?

[aleksandar.kasabov]

Hello greymiura,

I apologize for the delayed reply.

Would you mind sharing some examples and a test scene to demonstrate the issue? Also, please specify the exact version of V-Ray, Cinema4D, and your OS. Thank you.

[greymiura]

Hey Aleksandar,

thanks for your reply! I was already assuming that I posted a totally silly question...

Here's a little scene I was using to understand how it works - or doesn't.

https://we.tl/t-12SNi25fkn

00 Reference Object: The knobs are actual geometry, the maps ABCD and Test use UVW mapping

01 The knobs and the word Test are part of the normal map which uses UV mapping. And UV projection for ABCD as well. The object looks as you'd expect.

02 ABCD still in UV projection, but the normal map with the bumps and Test in triplanar projection. Looks like 01 where the orientation is (by coincident) the same as in UV projection (top and right). But on the front side V-Ray not only rotates the normal map, as you'd expect, but also the resulting surface normals accordingly, which doesn't make any sense, does it?

03 As in 02, ABCD in UV projection, the normal map with the bumps and Test in triplanar projection. Additionally, I rotated the UV polygons of B, C and D, which makes this strange effect even more obvious.

As mentioned above I also tried some different shader setups for the normal map in triplanar projection, but I couldn't get this working properly. Is it V-Ray or is it me? Thanks for your help, it would be great to be able to use this!

Windows 10, R25 and V-Ray 5.20.02

[seandunderdale]

From what I recall, unless things have changed recently, normal maps in Maya dont work with tri-planar either. We've been through a lot of forum posts and discussions about this, with no solution that Ive seen.

Vlado said he was looking into the Maya issue
https://forums.chaos.com/forum/v-ray...-problem/page2

[greymiura]

Thanks for that link! I remember reading some parts of it, too, among other discussions, when I started wondering. You're right, this is the same issue and it seems that the C4D version just inherited it.

[aleksandar.kasabov]

Hello,

Thank you for providing the scene and the requested details.

I have reported this in our internal bug-tracking system (bug ID: VC4D-1300). I will let you know once we have more information to share. Thanks.

[greymiura]

Hello Aleksandar,

thanks for advancing this matter! I'm curious...