Real looking glass (yes, again)

[Lupaz]

Samuel, thanks for making me realize that I came out in the wrong way.

I didn't know what trolling meant (English isn't my first language). Now that I know, I'm definitely NOT trolling. I'm not joking.

Some posts mentioned how I'm not listening to suggestions. That's because I don't agree with the environment being the only factor here. I don't agree that glass is just reflection. I know how to make my material library. I'm not new to 3D.


In regards with your suggestion, I wouldn't be able to do such a test. I know vray much more than any other rendering engine. It would take me forever to do that.

HOWEVER, speaking strictly about features the following render engines have a specific material for glass, if I'm not mistaken:

-Mental Ray
-Brazil r/s
-finalrender
-cinema 4D (may be with a 3rd party render engine, not sure)
- Maxwell (with actual dielectric properties)

Why doesn't vray have a glass material? Even if it's simple to make with the generic vray shader, as other people are saying, it would be a nice feature to have considering that glass is probably the single most used material in our projects. At least in architecture.

Also, who knows, maybe chaos group comes up with a fantastic glass material.

[Dariusz Makowski (Dadal)]

This is weird.

GLASS is one of simplest materials in CGI. There is just NOTHING to it. Its transparency + reflection + in some cases density of glass if there are different - but that's rarery used. Other render engines DONT have dedicated glass. They just have preset. (I mean MR)

[tricky]

This is one bizarre thread.

[yyk]

To be fair there are things like cutoff threshold, max reflection/refraction depth and such that affect the outcome. If the thread is a waste of time, why not simply skip it and move on?

[3LP]

Well, I'm not sure this thread is SO un-usefull TBH,
I might be the devil's advocate here because it seems that everyone is against Lupaz, but he does have some good points.

* For the library, he makes a point and it's a fact : Vray doesn't have one, now to know if Vray wants to make one or not, that's another point. I saw a post from Vlado saying the might consider it, and I see the interest for ppl to have access to Grant Warwick library, so that's just a fact as well.

* For the settings in the glass, a lot of ppl can just do 3 steps, but if you want to go into detail and have fog, (which I think would always be the case "physically speaking", even if it's not visible/noticeable) there should still be fog in any glass. I would like that someone show me a photo of a 0.5/1/2/5/10/20 meter thigh glass that has absolutely no fog in it... and that's exactly why when you do a glass table, if you have fog, you've got that black edge because the thickness is actually 2m viewing from the side. I have ppl here in the office that trick that by not putting fog and overwriting the egde color from the shell modifier with a dark material... You should not even bothering doing that (what if you forget?) if you had the right material straight. And yes I guess if there was a material preset, those artist (ie the one behind me, we don't need to look far to find one) would probably not use those "trick" but use the "correct" way, straight...

* I'm not a scientist, and I'm not a coder, but it seems to me that glass does have a certain fresnell properties that makes it behave like it should, or would. I know some ppl are setting the fresnell and then playing with it, some ppl goes for a falloff map to have even more control on it, and that's great. I'm not questioning that. But there are tonnes of different glasses (each one having different physical properties) and it would be great to have a preset that gives you at least the 5 most used glass with the properties straight in it. Like the FastSSS2 has... Or the carpaint material... why not for glass?
I read before that some ppl are using a blend to go into detail and having a coat on the glass, well, great, that's one that can be set in the presets, why should we be knowing what is the exact settings to setup each of the materials, TBH, I might not knowing them all, and it's been a long time I'm doing this. Or, why should I take 2-5-10 (or whatever) minutes to renders preview (and R&Ding) to suite the exact settings that needs to be set in the material to match what the material should be...

* Some ppl are setting the glossiness of the glass at 0.99, some are keeping it at 1, ok that's fine, for me it's more a personal/artistically point of view, but behind that, I guess there is a physically correct answer (that I don't know) : is it correct or not (again there are a million type of glass it might depending of the glass that you are trying to achieve) to say that there should be glossiness or not in glass...

* For the environment part, absolutely correct, it does make "all" the difference... And I've been in situation where I found my reflection not strong enough here and there, so I started upping the glass to ior 2. I'm going in another camera and there I see that the reflection is waaaaayyy to bright, So i'm thinking, 'OK, I was going too strong there, let's get it back to 1.8" and tweak the lack of reflection of the first render and the over-reflective amount of the other in post... BUT, if I had a client saying : "it's the glass xxx" and I'm selecting that glass in the preset, I know that for a ground rule, that glass should not been touch, IF I want to keep it as close as possible to something physically correct. IF I want to still change it for artistically matter, that's something else and I'm cool with that, but I think we should not mix physically correct and artistically point of view.
In this case for example, a red alarm would have flash in my mind saying "your environment is wrong". And it might have been the HDRI (not having enough range) or the sun and sky, or my camera not well exposed, or whatever, but I would not have touch the glass...

If we do have a preset, or library, or special material or a script, or whatever I think it would be useful for some person, that doesn't mean that every one in this thread need/will use it, it's just a option. Like you're still free to use hand made carpaint with beld and shellac materials, but other ppl will see the use of it, like having the Vraycarpaintmtl...
This doesn't mean that we should not still have the settings to tweak it as we want. (ie. using dispersion or not, reflect on back side etc) but just that as a start we would have a material that is closer to match the final purpose of the material, and maybe 99% of the time, we should not even touch it.

I understand what you're saying guys to Lupaz, but I think Lupaz tries to send a message, and even if he doesn't use the right way probably (comparing unfair images from different packages, not having any proof or visual example of stand his point) I think he is just trying to express a feeling he got.

Stan

[LarsSonparsson]

I have to add this. DOF

No one is talking about the dof. In my opinion it's really important part of realistic glass. Glass is that way unique material, that you can see 3 different depths at the same surface. And because glass isn't anything else than reflection, refraction and edges, you have to get them right. Depth is the reason why hdr environment map isn't enough for real looking scene.

Glass doesn't have glossy reflections. When watching reference photos, we are seeing dof blurring the reflections, not any property in material.

This might be too obvious, but I just had to say it.

Maxwell camera has dof always on and so should your Vray camera, when trying to achieve anything "physically correct" or realistic looking renderings.

[Dariusz Makowski (Dadal)]

Dof wont help you much if all you can see in glass is reflection of IBL which is at constant distance.

[LarsSonparsson]

Dof wont help you much if all you can see in glass is reflection of IBL which is at constant distance.

Yep, like I said, hdr environment isn't enough.

But in any other case it's the only way to make glass looking real. Just my opinion.

[flino2004]

Lupaz opened my eyes....no more settings...We want a new vray glass shader with a simple way to get nice looking glass with options like
-Maxwell glass effect.
-an user friendly calibrater... starting in cheap all the way to expensive or fancy....no more colors,IOR, fresnel,etc ( very useless by the way)
-automatic environment for reflection.

[flino2004]

Another handy option.... Pimp my glass.... Always On by default please

[Dariusz Makowski (Dadal)]

Another handy option.... Pimp my glass.... Always On by default please

Hahahhahahahahahah omg LOL

[Lupaz]

I can imagine 30 years ago someone saying to the -hand made rendering artist community-: "I want a computer that makes a rendering with 3D geometry". And someone else would say, "yeah, right. And it'll have lights and cameras and you'll be able to put materials on stuff and then the machine will draw the rendering for you".

Chaos Group: It'd be very nice to see your comment to 3LP's post (I wish I could have written that 80 replies ago). At least something, one word!?

[squintnic]

that one word is going be be.....

BAN

[grantwarwick]

I'm finding it pretty funny at this point.
How long can you guys keep feeding him?

[LarsSonparsson]

Lupaz or anyone else, what properties should Vray glass material have then?
It's kinda difficult to think anything that we could drop off from the standard VRayMtl. Of course we could arrange those properties differently and make a drop down menu for some presets and call it VrayGlass, but is it worth it?
If its going to be too simple, people starts to ask more advanced properties until its almost as feature rich as VRayMtl.

Just trying to understand what it could be then.