How do I set up PBR in V-Ray?

[The3DNut]

How do I set up PBR in V-Ray?

I have a model that I textured in dDo. It looks fantastic in Marmoset Toolbag but I am trying to figure out how to set everything up in V-Ray.
Albedo Map - Plugging in to the diffuse input of VRayMtl is pretty self explanatory, though I am not sure what the difference is between using the Image File Texture node's Output or Color output.
Emission Map - I am using one because I have some self illuminating parts of the model. This also seems pretty self explanatory with the Image File Texture plugging in to the Self Illumination input on the VRayMtl node.
Specular Map - To define the reflectivity of the surface. I plugged it into the VRayMtl's Reflect input via an Image File Texture node. Does the spec map go in here or is it looking for an Environment map?
Normal map - where does it go?
Gloss map - where does it go?
Metalness - where does it go? In Reflect? Somewhere else?
AO - Where does it go?

Thanks in advance to anyone who can help make this more clear for me.
Bryson

[bdancer]

It's very difficult to answer such questions because basically the answer is highly dependend on the result you want to achieve and i have no idea what dDo is and how it's supposed to be used. Do they have any vray tutorials? Have you tried contacting their support?

Output or Color output.

In most cases no different (if they are both yellow for example).

Specular Map - To define the reflectivity of the surface. I plugged it into the VRayMtl's Reflect input via an Image File Texture node. Does the spec map go in here or is it looking for an Environment map?

Have no idea what they think of "Specular Map"... could be "reflect", could be "glossiness", could be "Hilight glossiness"...

Normal map - where does it go?

You'll need an additional BRDF Bump node for bump/normal mapping (like vraymtl -> bump -> single). Then attach output or color to colot texture and setup normal settings.

Gloss map - where does it go?

Glossiness?

Metalness - where does it go? In Reflect? Somewhere else?

I have no idea what is "Metalness". Could be reflection could be anything...

AO - Where does it go?

What does it mean? Is this a baked AO texture? Well you could mix it with diffuse via "Color Operations" multiply for example.

[bdancer]

May be you could share a simple set of textures and some reference?

[The3DNut]

I did some looking around and it looks like I am not the only one confused by how to get a V-Ray Physically Based Rendering Shader setup. Since it sounds like you are not already familiar with PBR and PBR texture creation software such as dDo or Substance Designer, it sounds like I ought to put this on the back burner and learn by focusing on more simple things. FYI, in PBR, the gloss map is used to define microsurface details, metalness maps are used for specifying which parts of the model are metallic and which parts are dielectric. The specular maps are used to define the percentage of light that a surface reflects and usually used in place of metalness maps. Now as for Ambient Occlusion (AO), I would be shocked it V-Ray couldn't support that and I will try what you suggest. Thanks for the info on the normal map and the outputs.

Here are some details on how Marmoset Toolbag handles the PBR materials and what they are for in case you are interested.
http://www.marmoset.co/toolbag/learn/pbr-practice

Thanks for trying to help me with this.

[bdancer]

So, could you share some simple set of textures and some reference? It'll be much easier...

[vlado]

All materials in V-Ray are physically based materials. What those engines typically mean by "PBR" (and which is soooo misleading) is just a shader based on the Disney principled BRDF. You can find more information about it here:
https://disney-animation.s3.amazonaw...f_notes_v2.pdf

This may give you some ideas what corresponds to what. V-Ray does not have a ready monolithic shader like that bulit-in, but it can be put together from the existing ones - you will have to combine several BRDFs through a V-Ray blend material.

Best regards,
Vlado

[The3DNut]

If you are up to the challenge, I will provide you with 3 different assets here that are freely available. I cleaned up the resources and and made Marmoset Toolbag scenes (you can get a free trial of Marmoset Toolbag 2) so that you can check out what the target is. It would be fantastic this could be pulled off in V-Ray for Blender.

These two use the Specular Map (source files here: http://quixel.se/usermanual/quixelsu...id=ddo_samples)
https://dl.dropboxusercontent.com/u/...DO_SDK_AKS.zip
https://dl.dropboxusercontent.com/u/...ciFiHelmet.zip

This one uses a Metalness Map instead of a Specular Map (source here: http://artisaverb.info/PBT.html)
https://dl.dropboxusercontent.com/u/...ew_Maximov.zip

[bdancer]

Tnx, will look into this asap!

[Raypak_inc]

The3DNut i was wondering if you could allow me to download the files you provided: These two use the Specular Map (source files here: http://quixel.se/usermanual/quixelsu...id=ddo_samples)
https://dl.dropboxusercontent.com/u/...DO_SDK_AKS.zip
https://dl.dropboxusercontent.com/u/...ciFiHelmet.zip

This one uses a Metalness Map instead of a Specular Map (source here: http://artisaverb.info/PBT.html)
https://dl.dropboxusercontent.com/u/...ew_Maximov.zip