basics of glass / windows / glazing

[spadestick]

for most exterior renders we see, I think that the thing that lets the rendering down the most is the glazing. Can anyone give insight or an example, on how to get the glass looking like how it is in this attached image?

Getting glass right seems to be the most fudgy and difficult thing ever, and it never looks right.

[jenujacob]

different render engines takle glass in quite different ways...
in KT (kerkythea) for example.. the ASG is achieved by using a thin glass shader which is specifically developed to render single face glass.. but i read somewhere that in Maxwell u goota use thickness for ur glass...
physically correct render like maxwell, Kt etc rely on the IOR values too.. they actually translate the physical properties to simulate how light bends around it..
so i think its best to actually go to the techincal forums or read the guides/ tutorials of ur render application to seee how it deals with glass...
hope this helps.. and please do correct me if wrong :)
:cheers:

[spadestick]

thanks jenujacob... the question that always hits me is the reflectivity and transparency, and how to make sure that clouds or other buildings are reflected, such as in the image above, yet see through it slightly, and maintain and sky gradient. It never becomes right... always take 10 test renders before something decent appears - very troubling indeed. If there was a 1 hit render solution where glass turns out perfect everytime, it would be my dream renderer!

[jenujacob]

there are two possibilities that i see...
1) using a spherical/hemispherical sky or city scene... so that it would reflect the clouds and the buildings...
2) using reflection maps.. this is the most probable and easiest method.. becos it wouldnt depend on the viewing angle as in the previous case.. but however the scale of the reflection map should be adjusted.. kind of a trial and error actually....
these can be combined with the other transparent and reflective properties that u give to the glass material...
i never really had an occasion where i rendered any huge skyscraper with glazing.. these are really some of my theories.. maybe the pros out there could pitch in???

[dpiero]

Architects design buildings, 3d artists make them look good before they are built

If architects can render them as-well, then that's a big bonus...but as most of you guys on this forum want a push button solution from all the rendering programs you hail, then just hit the render button on your rendering program, and you should achieve the the desired effect. Simple really.

If not, then use an expert or learn.

[Jimmern]

Jenujacob has it right - to get decent looking glass you really need some kind of environment around your model to get some good looking reflections going. The methods for doing this vary from renderer to renderer, so you'll have to adjust your method to your renderer of choice.

TurboSquid has a lot of cheap 360 panos to chose from HERE (http://www.turbosquid.com/Search/Index.cfm?FuseAction=ProcessSearch&intStartRow=1&istSearchKey=360+sky&intMediaType=-1&Submit.x=0&Submit.y=0). I'm sure you can find some free ones if you look around.