Help to create perfect glass VRay material

[Morne]

Hi all

I'm trying to get a perfect glass material but I think I'm missing something.

Here is my current settings. (Using LWF for rendering on a 6mm thick glass panel)
Get default VRMtl then only change these settings:
Diffuse = 0,0,0
Reflect = 220,220,220 and tick "Fresnel Refelction" set Subdivs = 20
Refraction = 255,255,255 set Subdivs = 20, tick "Affect Shadows" and set Affect Channels = "All channels"

That's it for the main glass material. Is that fine so far? Now the question Real glass isn't perfectly white and has a very slight greenish or blueish tint to it. Do I change the "Fog color" for this or the Refraction color swatch?

Then part 2 of the question. The edges glass usually looks much darker and more green/blue than the main part of glass. For this obviously you apply a different glass material. I'm geussing this can be the same as the main material but with either the fog color or refraction color darker?

Your thoughts on this would be very much appreciated.

[tricky]

I tend to put a slight green tint in the fog colour. You shouldn't need to have a different material for the edges. Fog and refraction will take care of that. I would put reflect to 255,255,255 and refract to, say, 250,250,250.

[Morne]

Thanks Tricky. Now another issue. I'm sticking a VRayHDRI on my reflection override in Vray Environment. All I have in my scene is a glass panel (window glass) and a square floor and obviously vray cam/sun. Now looking through the glass sort of in the middle down you can see the square floor and then above this the VraySky suppose to be, but here the refelction of the HDRI is so strong it makes the glass almost black here asif it is not seethrough, the HDRi is almost black here where the background (VraySky) is suppose to be.

What's up with that?


(hehe after typing all that I remembered I could upload an image)

[Olli96]

Cant help with the problem above but i also like to change the Fresnel IOR of the reflection and refraction. Even tho it might not be physically correct it works pretty good for me. So a basic glass setup would look like this:
diffuse: 0 | 0 | 0
reflect: 250 | 250 | 250, Fresnel Reflections: on, Fresnel IOR 2 to 2.5
refract: 250 | 250 | 250, Affect Shaodws: on, Fresnel IOR 1.1

[simmsimaging]

Make sure your trace depth is high enough. The default is 5 and 5. I usually set it to 25 each or more for complex surfaces. If you are using RT you will also need to increase the default trace depth too.

For the green tint I would avoid using any colour in the refract slot unless you want to create the effect of a tinted film. Fog will do what you nee more accurately.

I also often split the reflect and refract IOR values to cheat things. It can be handy in a lot of cases.

[tammo]

If you do large glass windows you can also put a bulge texture into the bump map slot at a low value. That simulates the slight deformation of the windowglass because of pressure differences. You can see that effect in pictures of skyscrapers.