Arch & Design material (3ds Max, mental ray) render result is too glossy, which parameters to tweak

Valentris

Greetings everybody,

I have some questions regarding to Arch & Design material (3ds max with mental ray) - the main issue is that render results appearing to be too glossy in comparison with what I see in texturing programs (mostly Substance Painter, though I have pretty similar case with 3D Coat).

It seems like material needs some additional tweaking, yet I'm not sure which exact parameters I should change.

My workflow:
1. Exporting Diffuse, Normal, Specular and Glossiness maps from SP;
2. Creating standard Arch & Design material in 3ds Max, putting for mentioned maps in Diffuse Color, Bump (Normal map), Reflection Color and Reflection glossiness maps respectively with no additional tweaking;
3. Putting material on the model and render result (which appears to glossy).

I getting result way more close to SP render with Standard material, but it also need additional tweaking (in reflections part), so I would prefer to getting it to work with Arch & Desing (which is, I assume, considered to be more suitable\advanced for mental ray).

Overall, my questions:
1. Are there some additional parameters I should tweak? I set up SP to have Diffuse, Normal, Spec and Gloss maps as output, are those enough to correctly set up Arch & Design material to look the same way, or I still require some additional maps like IOR and Anisotropy, even though I don't have such channels in my SP project?

2. In preferences, I have Gamma\LUT correction option disabled (it saves me from Normal Map issues), could it be cause of the issue? From time to time I see guides that insist on overriding gamma when importing maps to Max, but I'm not sure if in this case I should bother.

Thanks!

musashidan

1 - MR A&D is an old pre-GGX shader. The IOR/Fresnel will not match SP. I don't even think that there's an MR preset in SP. Try exporting one of the other offline renderer presets. These presets(older ones) should output all the channels you need including the ior/fresnel.

2  - MR is a physical renderer designed for a linear workflow. Don't disable gamma. Max's normal tangent basis is its own and is different than SP(native MikkT) therefore normal map results may be unexpected. Make sure(with gamma enabled) that you override all data maps to 1.0(normal map and all other non-RGB maps) in the bitmap import dialogue.

Note: because of the reflection/ior shading model that A&D material uses you may have to colour correct reflection/glossy maps to achieve a simiale result to SP. Do this in the shader in Max.

Lastly, what version of Max are you using and why are you still using MR as your renderer?

Valentris

Many thanks for guidelines, musashidan, really helpful.

>Lastly, what version of Max are you using and why are you still using MR as your renderer?

Max 2015, regarding to MR - not knowing much about rendering I just thought of it as maybe less customizable, yet still usable (not conceptually outdated). Guess it's wrong and everybody use plug-in ones?

Eric Chadwick

Mental Ray is not a terrible renderer, you can get good results if you work at it. But there are better alternatives. Arnold is now included in Max. We use V-Ray here, not free. Corona is another nice alternative.

melviso

MR...where do I begin? I remember tweaking the parameters to try and stop light leaking to no avail. That was terrible. I would not recommend MR  for archviz especially interiors.

Valentris

Thanks, gonna dive into those aforementioned alternative renderers.

poopipe

   There's nothing much actually wrong with mental ray, it's just outdated - it's perfectly capable of producing excellent results - even if they're not as correct as more modern systems. It was pretty much industry standard for a decade after all. 
  If you can move to Arnold then I'd suggest you do that but don't expect things to get much simpler - if anything it's more complicated in some ways. 

I certainly wouldn't suggest paying for a plugin renderer until you understand why having it would be better than what you already use - it's possible to create equally shit results in all of them if you don't know what the buttons do

Valentris

Oh, I understand - I'll definitely going to do some research before jumping into new renderer - just want to be a bit closer to current standards.

musashidan

@poopipe MR was my first physical renderer. I started using it just before A&D material, when you had to cobble the materials together from shaders. It was quite the experience coming from legacy pre-linear workflow scanline rendering where you had to actually plug a raytrace map into the material to get reflections.

Yes, MR was a perfectly decent renderer in its day when you knew how to use it. My curiosity was more to do with the fact that it's discontinued and Arnold is now the native Max renderer. I was going to advise OP to look into Arnold if he has access to newer versions of Max. All the offline renderers have now moved to some form of metal/rough and all are using GGX microfacet shading of some kind. MR is not only dead, but obsolete. Although having said all that, if it's all that OP has available then it's still a viable option to learn the basics/concepts of physical lighting/shading/rendering.