How to incorporate metal maps and ambient occlusion maps into materials?

[FrankGehry]

I purchased some material packs from Friendly Shade. Some of the materials include a metal map to highlight metal elements within the texture (screws, bolts, etc.) and an ambient occlusion map to give shade and depth to certain parts.

Can anyone provide some guidance on how to correctly incorporate these maps into a material? For instance, I think the 'metalness' map (as Friendly Shade refers to it) would go in the highlight glossiness input, but I'm not certain if there's a right way to go about it. The ambient occlusion map is the trickiest one.

[GD3DESIGN]

Hey FakeFrank,
You should research 'PBR Material Workflows' to get an idea of what you're dealing with.. Basically, there are two main workflows to choose from for creating shaders: Metal/Roughness and Specular/Glossiness. Vray for sketchup uses Specular/Glossiness. Vray Next for Max has added options to use the Metal/Roughness.....and I imagine we'll get that option when vray for sketchup 4 (Next) is released...but for now we are stuck with specular/glossiness.

PBR materials (metal/roughness workflows), have gained popularity lately and are used in Unreal Engine and Allegorithic programs, substance designer & painter, as well as other popular renderers & game engines. You can read about the theory etc in Allegorithmic's PBR guide and Chaos group's recent article about metalness:

https://www.chaosgroup.com/blog/understanding-metalness

https://www.allegorithmic.com/pbr-guide


So anyway, those metalness maps might not be of much use in vray 3.6. If you wanted, you could use the ambient occlusion map in a mix operator set to multiply or you could use it as a mask in a VrayDirt texture....? But yeah, to use them correctly, they are made for a whole different workflow. If you get into Unreal you can use them....or just hold onto them until the new Vray releases. Either way, those are some great looking textures at friendly shade...(and not cheap).


Cheers!
GD

[FrankGehry]

Hey FakeFrank,
You should research 'PBR Material Workflows' to get an idea of what you're dealing with.. Basically, there are two main workflows to choose from for creating shaders: Metal/Roughness and Specular/Glossiness. Vray for sketchup uses Specular/Glossiness. Vray Next for Max has added options to use the Metal/Roughness.....and I imagine we'll get that option when vray for sketchup 4 (Next) is released...but for now we are stuck with specular/glossiness.

PBR materials (metal/roughness workflows), have gained popularity lately and are used in Unreal Engine and Allegorithic programs, substance designer & painter, as well as other popular renderers & game engines. You can read about the theory etc in Allegorithmic's PBR guide and Chaos group's recent article about metalness:

https://www.chaosgroup.com/blog/understanding-metalness

https://www.allegorithmic.com/pbr-guide


So anyway, those metalness maps might not be of much use in vray 3.6. If you wanted, you could use the ambient occlusion map in a mix operator set to multiply or you could use it as a mask in a VrayDirt texture....? But yeah, to use them correctly, they are made for a whole different workflow. If you get into Unreal you can use them....or just hold onto them until the new Vray releases. Either way, those are some great looking textures at friendly shade...(and not cheap).


Cheers!
GD

Thank you for the input! I still have a lot to learn in the realm of arch. viz. so explanations like this are helpful. I will certainly look into these topics. I might look into Allegorithmic's software as well.

[GD3DESIGN]

You're very welcome! I def recommend getting into the Allegorithmic Substance suite. A bit of a learning curve, but amazing software...and it's where the future lies (and its very fun to use).

Although, Substance has plugins that integrate directly into Max & Unreal, we don't have that in Sketchup....but you can export all your needed maps from Substance in Spec/Glossy workflow to be used the usual way in Vray for SU. (keeping fingers crossed for Substance integration into SU for Vray...)

If you get a free trial of Substance Designer, they have great tutorials to get up and running....Lynda & Pluralsight have some good tuts, also. Cheers!

[GD3DESIGN]

You can also use their free 'viewer' to tweak .sbs files and output maps:

https://www.allegorithmic.com/products/substance-player

You can download substances to play with from Substance Source:

https://www.allegorithmic.com/products/substance-source

[FrankGehry]

You can also use their free 'viewer' to tweak .sbs files and output maps:

https://www.allegorithmic.com/products/substance-player

You can download substances to play with from Substance Source:

https://www.allegorithmic.com/products/substance-source

Thank you for pointing me toward these resources!

I've noticed that only a few material maps I bought from Friendly Shader have the metalness map. Most have maps that can be incorporated in the V-Ray asset editor. For glossiness maps, I presume that is plugged into the glossiness setting, but then what is the reflection color set to? Should it be set to pure white or is it dependent on material and how the glossiness map is generated? I guess I'm wondering if there is any rule of thumb to follow when using maps from various sources.

[GD3DESIGN]

Hey man,
I think really the only way to learn this is to just get in there and get your hands dirty. There isn't a hard-fast rule of thumb...it varies per material and that is where you earn you bacon as a '3D artist'. As a starting point, just trying throwing the maps into the Reflection & Reflection Glossiness maps slots. One at a time, then try both....then try the map in one of the slots, then only adjust the slider on the one without a map in the slot. You'll start to get a feel for the difference between reflection & reflection glossiness and how they work together along with reflection IOR to make materials look realistic.

What the 2 settings basically do:

1)The 'Reflection' setting controls the amount of reflection/reflectivity/reflection intensity(not sure best way define it)..or which part of the texture will receive reflections....think photoshop masks. You can also tint the reflections here if you use anything besides grayscale....which is how you create metals such as copper, gold, etc.

2)The 'Reflection Glossiness' controls how sharp or blurry the reflections are.

Then the IOR controls....well just look that up if you don't already know. But it controls the Fresnel value which defines what angle the reflections are stonger....(that's a horrible description.) Metals have a very high IOR which is why they reflect from all angles, vs a piece of wood, or a rock or wall, which only reflects from a higher angle.

As always, I'd recommend reading through Chaos Group's help docs on the subjects....they always include some picture samples to help expain things more clearly....and I could be totally expaining it wrong, too! ;p

cheers!


https://docs.chaosgroup.com/display/...l+%7C+VRayBRDF