Scene converter reflection issue

[TerriBrown3D]

Hi guys,

I have an issue when using both the native 3DS Max scene converter and the Vray Scene Converter: when converting from a Physical Mtl to VrayMtl the converter always adds a fully white colour in the reflection slot and 0.0 value in the roughness/glossiness slot. I'd far rather have a black slot and go from there. Is there any way to change this?

I'm using 3ds Max 2022 and the latest build of Vray.

Thanks,
Terri

[hermit.crab]

This is most likely because your Physical Materials have their reflections enabled. In the Physical Material node, switch the Material Mode to "Advanced" to check the separate "Reflections" parameter options and see if that is indeed the case.

[TerriBrown3D]

Thanks Aleksandar,

Is there a way to do that globally? If I have a scene with 200 materials it would be quite a challenge...

[^Lele^]

If you could send me one such problematic shader (mail will do), i should be able to get you a simple script to fix them.

[TerriBrown3D]

Hi lele. Apologies for the ridiculously late reply. I'm sending you a file now - I have just done the scene converter.

[TerriBrown3D]

Hi Lele. the script you sent me doesn't seem to work anymore...think since I updated to max 2024. could you possibly send one that does??
I still find it crazy that the vray scene converter makes everything full reflection

[^Lele^]

Hi Lele. the script you sent me doesn't seem to work anymore...think since I updated to max 2024. could you possibly send one that does??

It works for me in 2024, what's the error on your side?

I still find it crazy that the vray scene converter makes everything full reflection

It's the way the physical material is built, conflating diffuse and reflection (see below), which creates logic conundrums.


I'll look into the code again and see if i can make it better.

Edit: so the issue is with the fact that the material has more than one "mode", and the simple mode hides things from the user.
Specifically, an Autodesk Physical Material used in "Classic Simple" mode (that's how they are in the scene you sent me at the time), will hide the presence of a white reflection colour.
Switch the material to "Classic Advanced" and voila', the reflection color now has its own swatch, and it's white.
Your shaders had a diffuse texture, and the glossiness set to 0.0, which is the only way to zero reflections in simple mode.

Here we are: there is a hidden white reflection color with a 0.0 glossiness. the converter is doing it right.

here's one of your shaders in simple mode:

And the same, sitched to advanced:

Notice the white reflection with 0.0 gloss, just as the vrayMtl conversions.

[TerriBrown3D]

thanks for that detailed description lele...not that I understand too much of it

so I'm not getting any error message. It just does nothing. at all.

even if gloss/roughness is set to max, I don't mind. It's the pure white reflection slot that's an issue...especially when converting a scene with hundreds of different materials. Which I have recently been doing

[TerriBrown3D]

I'm not too sure why it's not working my side though? Any ideas?

[M.Max]

A quick work around is to use VMC script to set the reflection color back to black and the glossiness to 1.0 for all the scene or selected objects materials
https://www.oliverradford.com/3ds-ma...erial-control/

semi-off-topic :
Most materials nowadays like ( Max Physicals , Corona physical mat , Unreal Material..etc) are using the "PBR" workflow that assume that the reflection is full white for all non-metallic materials and the only difference between these materials is the glossiness/roughness .
some of them like Corona renderer doesn't -by default- allow the user of changing reflection color , using higher IOR than 3.0 or even using sperate glossiness value for reflection and refraction just to make sure the PBR rules are respected by the user .
I personally like the VRay way which give more freedom to the user to follow or break the rules as desired .

[TerriBrown3D]

Thanks a mil...that script is a winner!