cant make good windowglass

[max montana]

hi erveryone,
my first trials with vray. biggest problem i have is to make a good looking windowglass, with correct mixture of transpareny and reflection. i have a hdri in the scene which should be reflected in the glas, but the sky seems not to be reflected, the houses reflect strongly in the windowglas. please help me.

the 4. image is not mine, it shows how i would like the glass to appear in the rendering.

[werticus]

http://www.vray-materials.de/

im sure you'll find something

[Joost Ink]

other things to keep in mind here is that if you are using vraysun, your hdri needs to be boosted to compete with the sun.
and... make sure you have good geometry for your glass, preferably with thickness.

[stevesideas]

I usually make my glass material a white diffuse not black. Instead of using a fall-off map in the reflection slot, just tick the fresnel box.

Make sure glass has a thickness as stated above.

I think maybe your camera angles are causing a lack of reflection of the sky. Is the cloudy sky actually a reflection map..used in the reflection override ?

[joconnell]

Joost has hit the nail on the head - the sky is far brighter than you've got your environment bitmap set to - if you're using a bitmap in the environment slot to get reflections, drag a copy of it into the reflection override slot in the environment section of the vray render dialog and boost it's output up a good bit - you might find that it's a bit flat so you could play with the output curves a tiny bit to make more difference between the sky and the clouds so they read a bit better - how is the environment set up in the current scene?

[beestee]

Why use a falloff map instead of the in-built fresnel? You say that your reflections on the high-angle glass is too much, but the reference image shows much much more reflective glass than yours. The glass in the example looks to have a little tinting, which in VRay I would handle using the fog settings. I could give you some settings, but they are very dependant upon your specific units settings, items from vray-materials.de do not take into account your units settings either so consider that if you want to go that route. The background image really doesn't seem conduscive to good reflections either, it seems to be lacking contrast when compared to your buildings. You seem to have a good start though!

I am also wondering about the reference image...the reflections look like post comp to me. Actually, most of that image looks like quite a bit of post work was done to it, so it probably isn't the best example for material reference. Try matching some real-world examples and you will probably have an easier time.

[glorybound]

glass

If it is a still you can get great results in Photoshop. I usually run a matte pass for glass and do a paste into.

[max montana]

@ werticus:
actually this is a vray-materilas.de material( a little modified)

@ joost ink:
there`s no vray sun/sky in the scene, just hdri+direct light.
what do i have to take care, because of the geometry, glas is a box with thickness of 1cm.

@ steve iouk:
i have no concept in making glass, just looked at the other glasses in vray-materials, and all over diffuse colors over there are black or dark.
i`ll try it with white diffuse.
refl/refr. env. override is unchecked.

@joconell:
i´ll try this out, actually there`s a copy of the vray hdri in the background/environment map, as in the vray gi-environment.

@ beestee:
display and system units are set to cm. will try it with a more contrasty hdri.

@ glorybound:
will give it a try, and post progress.

thanks for your replies

[paulison]

I'm guessing that they used a spherical environment map in the reference image or else mapped what they wanted to be reflected on a plane.

I've always found that HDRI's dont make good reflection maps if their purpose is lighting. and unless you take your own spherical reflection map for the specific job, these also generally don't look very good and your reflections may come out distorted.

The problem with glass isn't the glass settings but what is the glass reflecting?. The areas where you can see reflections look good to me but thats only because it is reflecting other parts of your scene.

Personally i think a simple direct sun and flat envorinmental colour combined with a nice background and mapped 'reflection' planes would look better than what you have currently. Its just an alternate solution to getting what you are looking for. It also has a bit of a LWF feel to it as well (looks a bit flat and lacking in contrast) but thats just my personal opinion.

In general everything looks great to me in terms of your scene setup and modelling etc and i'm sure the glass material is actually pretty good.

everyone seems to do things the same way... HDRI, LWF, 'falloff' instead of fresnel, vray sun+sky. Gotta remember that these are just tools and options, not solutions and there is no right/wrong way, just your preferred method of achieving the desired results so don't be worried about cheating a bit to get nice reflections

[max montana]

here is my last rendering, just did a little level adjustment in ps.
i changed from "hdri+direct light" to "vray sun/sky+vray phys cam" with the setting from anotother thread.
i am quite satisfied with the window glass, will desaturate it a little more in post, and edit grass and sky...

next pic shows a problem i have: when i set vrayshadows as a render element i get this overexposed render result in rgb. the mask for the shadows is also not correct. is there something to bear in mind when i make render elements with vray sun/sky?


some other problems occured, maybe someone can help:
1.) i cant see the dialogbox when i click on "show correction control" in vray vfb, although i klick on "use exposure correction, etc)
2.) do i have a possibility to adjust the shadow intenstity with the vraysun/sky?
3.) can i adjust a time in the vray sun/sky system?

@ paulison. thanks for all the advices, will try them out in the next tests, especially the reflection planes.

[glorybound]

do i have a possibility to adjust the shadow intenstity with the vraysun/sky?

I think you can accomplish this my decrease/increase your skylight environment multiplier.

can i adjust a time in the vray sun/sky system?

You can link it to your max suns system or create a max sun system and change the Sunlight to v-ray and turn off the Skylight (v-ray 1.5 only, I think).

http://www.vrayelite.com/camskycontent.php

[max montana]

@glorybound:
when i reduce the sun intensity multiplier of the vray sky, i reduce also the brightness of the image. i know it`s about the correctnes of the lightning that there is no adjustment for the shadows in vray sun, but it would be nice to have one as often the shaded areas - especially in bright pictures - are far to dark.
when i print the pics, the shaded areas are nearly black. i help myself with shadow render element and brighten up the shadows in post.
thanks for the tip with the may sun system.

[Joost Ink]

as far as dark shadows concerning; check some topics about linear workflow aka LWF, dont get drawn back about all the info about it, it comes down to a few simple settings. But it would be good to know the theory behind it to understand and be prepared to read a lot.
there are some good topics about it here. and lele posted some good tutorials about how to deal with it.

[Da_elf]

ive never really gotten into that lwf stuff and as for my flass i just shove an egz glass into my scene and it works nice enough. for water i convert egz glass to vray material and add a bump and change IOR. for dark glass i just change egs glass to vray material and lower and tint the refraction
http://www.elfpro3d.com/Abacus/2s.jpg

[max montana]

@ joost ink: i am very new to vray, and so i want to learn things step by step. when i intentionally checked the forum i often read about the lwf, and saw people with lots of posts struggeling with it. i think it´s the way to go , but at first i would like find setups for different kind of scenes with color correction.

@da elf: what is "egz glass"?