If VRAY doesn't have a single face glass option... could we have one? like MR?

[JD3D_CGI]

If we do have it, can it be a default maon this new materals default thing we've been talking about - and or can someone let me know how it's done?

[Morbid Angel]

I believe rens has a thread here called osl shaders, it has single face glass osl, check it out.

[vlado]

It's somewhere on the "to do" list... In the meantime you can do it with the Physical Material in 3ds Max 2017, which V-Ray supports.

Best regards,
Vlado

[Rens]

I believe rens has a thread here called osl shaders, it has single face glass osl, check it out.

Yep! Here's the link:
http://forums.chaosgroup.com/showthr...925#post696925

Does that work for you, architectureinmotion?

[JD3D_CGI]

Thanks Ren - nah, it's over complicated and involves installing more things on more machines.

I just want a glass that turns of refraction but keeps reflection.

I can add a slight noise to the bump to get warping.

I prefer to keep it in Max as much as possible.

Thanks though.

[LudvikKoutny]

You can make thin glass with V-Ray already, but the workaround has one very significant limitation, it can be only clear or grayscale glass, it won't support any color.

Create VrayMTL, set reflection color to 100% white, turn fresnel off, enable "reflect on back side" and switch opacity mode from stochastic to normal.

Now you should have VrayMTL that looks like perfect mirror. Then get falloff map, set it to fresnel mode, set fresnel IOR to 1.52 and put this map inside of opacity slot of your V-RayMTL.

This will do exactly what thin glass in other renderers does. But as I said above, it won't work with color, because V-Ray does not support colored opacity channel. So in the end, we will still need proper thin glass mode.

[Rens]

Thanks Ren - nah, it's over complicated and involves installing more things on more machines.

BTW you don't need to install it, it's similar to loading in a bitmap as it's just a text file you're loading up. You can place the OSL file on a network drive so all machines can read from that same location.

[Rens]

Also, it is possible to have coloured opacity for a single plane if you don't want to use refraction by layering a VrayMtl on top of a VrayLightMtl:

- Create a VrayLightMtl, set the Light Color to black. Plug a VrayColor map into the opacity, this needs to be inverted so if you want red tinted glass you need to set it to RGB 0, 1, 1, for example.
- Create a VrayMtl, set the reflection colour to white, Fresnel off, reflect on backside on.
- Create a VrayBlendMtl, plug the VrayLightMtl in as the base and the VrayMtl as the first coat.
- Create a Falloff map and set it to Fresnel, then plug that into the VrayBlendMtl as Blend1 (the blend map for the VrayMtl).

Note You need to considerably raise the front facing reflection amount as the above setup will only be for a single side of glass which doesn't exist in reality. A single pane of glass already has two sides that reflect light back (front & back). Standard windows nowadays have 2-3 panes which has 4-6 reflective surfaces and this is not even taking into consideration the reflection bounces between all those layers (the archglass OSL shader does).

I advise you to use the OSL shader if you want accurate reflection amounts.

[LudvikKoutny]

I think the point is that people want something simple. Making a thin glass should be matter of checking single checkbox in V-RayMTL. If you show them external shader with 24 user interface elements, it's gonna scare most of them away (including me). Programmers seem to forgot that sometimes "less is more" rule really does apply

[Rens]

That's a fair point.

In the case of the archGlass shader all you need to start with is the number of panes option, the rest could ideally be in an 'advanced' rollout, however OSL doesn't allow for that (yet).

The MR or Physical Material thin wall materials are, as far as I know, only set up to reflect a single side of the window, correct me if I'm wrong. Which is why a lot of window reflections tend to look way too dark compared to real windows, which would have 2-6 sides reflecting light back.

[LudvikKoutny]

That's a fair point.
The MR or Physical Material thin wall materials are, as far as I know, only set up to reflect a single side of the window, correct me if I'm wrong. Which is why a lot of window reflections tend to look way too dark compared to real windows, which would have 2-6 sides reflecting light back.

Yep, they probably would, yet in 8 years of my career, I never ever needed more than one reflection layer on thin glass. When I needed more, I just duplicated the geometry, and when I wanted internal reflections, I inevitably had to use regular refractive glass.

It's just that at least I, personally, don't want to even spend my mental energy on anything more than clicking one checkbox to make thin glass happen. Definitely not think about multiple layers and dirt and all the complexities of UI as long as I don't want to

It definitely is an useful shader, and will definitely help out a lot in certain niche production areas. But I would still like the simple variant first

[Rens]

Thanks! And yes, the point ultimately is to give people more available options to pick from. : )
Out of interest, would the same shader but simplified to 1-2 UI items be a better option? I'm trying to get an idea of what people feel they would use. Or is the whole OSL thing in itself too many steps already?

[LudvikKoutny]

Thanks! And yes, the point ultimately is to give people more available options to pick from. : )
Out of interest, would the same shader but simplified to 1-2 UI items be a better option? I'm trying to get an idea of what people feel they would use. Or is the whole OSL thing in itself too many steps already?

I don't think OSL installation itself is a problem. For me personally it's not. But I would still not be at ease knowing that I rely on some third party tool for such essential task. Simple thin glass would make me a bit happier. I think all that's really needed for basic one is Fresnel IOR, Reflection Color with map input and refraction (transparency) color with map input.

But then again, I did a lot of dirty thin glass materials too, where I masked out refraction color to allow some diffuse color in, like dust and dirt. And they sometimes had bump mapping, mapped reflection glossiness, etc... Or even some glowing self illuminated HUD elements.

In the end, to be sure that you will have everything you need in production, you will need pretty much complete VRayMTL with one more checkbox to enable thin mode. There are so many material that require combination of thin glass mode with other material aspects/components. Now imagine having to do all that in OSL and make some sensible UI for that To me it sounds scary. So while the issue can be partially worked around with OSL for very simple thin glass materials, I think inevitably, we still need that checkbox in stock VrayMTL.