Standard glass is black

[koolvis.studio]

Its probably me. But, when vray standard (or any) glass is applied to a a glass material made in skp it shows and renders black and opaque. Always. Is there a workaround?

[Mousa_SA]

Be sure that the glass faces have a thickness , and apply the glass material on the front and the back faces, I hope that helps.

[koolvis.studio]

Tx. for the tip. In any model we make (large scale, big halls, exhibitions) it is impossible most of the time to add thickness. In this space for example the roof is arched with glass parts where adding thickness is completely unnecessary and a waste of billable time plus added complexity and filesize (growing until 500 mb later). Glass should be glass, not a complex extra because of vray. Is there a workaround or is it just vray not working?

[GD3DESIGN]

No, you dont need any thickness to your glass. I find it to just slow renderings down...unless you're in your mama's basement doing a highschool art project. (or commissioned by someone with too much money to produce top-shelf renderings.)

Try this and see if it works for you:

----Make sure there is only 1 face (or only layer of faces), representing your glass, with the front side facing camera.
----I like to isolate the glass all together in one group, with no materials applied directly to geometry. You can right click on group and select----->UV Tools----->Remove materials---> to make sure you dont have any back face materials muddling things up.
----Apply glass material to ONLY the whole Group.
----Then, edit your glass material: take the refractive IOR down to something like 1.1.....and do away with any fog settings and set refraction to pure white.
----Once things look half decent, you can tweak refractive IOR/Fog color/refraction settings a bit at a time if needed, to produce desired results. (Unless I'm doing glassware type of things in kitchens or bathrooms, I usually cut my glass materials down to totally clear with reflecting to cut down on render time and let full light in. Though, I'll often cut down refraction on windows for exterior concept rendering to give that 'black window' look and not show the empty interior)
***Anyway, Big culprits are backfaces & materials applied to backfaces, as well as overlapping faces/geometry.....and imported geometry from Revit, ArchiCAD, 20/20,etc...(which can all bring in a lot of overlapped geometry and backfaces...)

Let me know if this works for you or helps at all. If still having trouble, share a sample of your scene and I'm sure we can suss it out very quickly.

cheers!
GD

[koolvis.studio]

Tx, I'll try in the weekend slowness. I see one little problem: glass in models is often viewed from both sides in different scenes (glass doors for example and office cubicles). Which makes applying to front a little complex, especially within a batch render series.... Chaos: do you offer a glass material without all these restrictions somewhere? Glass which acts like glass when applied as-is? It would save so much time....

[GD3DESIGN]

It won't be a problem for those situations, like glass doors, as long as you follow those steps. Just remember if you aren't applying thickness to the glass (using an un-extruded face), then lower the refraction like I said above, to closer to 1. You'll be fine if you follow the steps above and make sure there glass material is applied to both sides - no other random material on the back face. (also, if your are doing a simple door, its pretty easy to just extrude the face and just use a normal glass material.)

As far as the dumbed-down glass.... VRay is arguably one of the best and most complex Renderers on the market. The glass acts like real glass.(in fact, you can get real deep with settings like fog color, refraction glossiness, and abbe dispersion.) That may be why you're having so much trouble. Also, any renderer you use will have problems if you have sloppy geometry with overlapping and or reversed normals.


Just remember, if you are using a physically based IOR, like 1.55 for glass., then you need to model the glass to the real life thickness it will be when built. If you are using 'fake modeling', as in a simple face with no thickness, then you need to 'fake' the glass material, too - as in lower the refraction's IOR. If still having any problems after that, you need to look at the modeling - overlapped geometry/reversed normals/wrong material on back faces.

hope that helps, cheers
GD

[ana.nedyalkova]

Hi,
As Mousa_SA commented earlier, the proper way to set up realistic materials for Glass in V-Ray is to have the proper thickness to the geometry you intend to use as refractive surface. If you want to take advantage of the full potential of the V-Ray this is the way to go. The Library preset glass materials are designed to work this way.
If you insist on using simple planes for windows there is a preset material called Fake Glass which can be used for this purpose.

[peerman]

Hi, If you render interiors most of the time you could also just render the exterior windows without glass. If you look to interior photos (with daylight) the reflections are almost non existant because of the extreme bright light coming from the outside. So for facade windows in combination with interior renders just remove the glass (or place it on a seperate layer so you can toggle it on and off). Maybe that helps a little bit?

Best,