Reflection on back side material in Windows??????

[luisgamino2]

Hi Konstantin and Peter Chauchev

I have a question... when should i use these option?
i AM modeling My proyects as in real life, Windows have thikness and Also the real thikness 6 milímetros or 9 milímetros, ticking that option gives better reflection, but when should i use these option??? Also i apply the glass material on both sides, or what kind of benefits can we get when we tick that option???

Thanks in advance

[nikoleta.garkova]

Hey luisgamino2

The Back Side Reflect option will calculate the back-facing surfaces reflections when enabled, i.e. - when disabled, reflections are calculated for the front side of the objects only. Keep in mind that this will affect total internal reflections too (when refractions are computed). Moreover, parameters such as Sheen, Coat and Reflections are affected by this option.

So, when enabled, this option will make the glass objects more realistic, but at the expense of calculation time. Do let us know what result you wish to get, so we can give more guidance on how to achieve it.

[luisgamino2]

Hi Nikoleta Garkova

Thanks for the answer i apreciatted the feedback, finally understood how does it work, just the last question as You said this affects Also parámeters like sheen and coat ( great improvement in vray 5 ) right Now i tick that option for glass vases and Windows as My Main goal is render at the highest level and this option gives a better realistic result in glass material, so right Now i AM rendering some barnished Woods and some furnitures, ticking that option helps for a better reflection in solid things like Woods??? Even if they dont have refraction???

Thanks in advance

[nikoleta.garkova]

Hey luisgamino2,

I'm not sure I completely understood you, but this forum post actually explains thoroughly the Coat and Sheen parameters best use-cases and properties. You can have a look and see if you find that info useful - https://forums.chaosgroup.com/forum/...97#post1095697

[luisgamino2]

Hi Nikoleta Garkova

Let me check that forum, and thanks for your help!!!

[konstantin_chaos]

Hi luisgamino2,

ticking that option helps for a better reflection in solid things like Woods??? Even if they dont have refraction???

The backside reflect option will not make any difference for solid objects.
It only makes sense for refractive objects.
The idea is that in reality every glass surface that the rays pass through reflects and the reflections are sort of added together when you look at a window.
If for example the window has a two glass sheets there will be 4 reflections that add up.
To simulate the same reflection strength in V-Ray you'll have to enable the option and model both glass sheets.
If you don't have the correct setup in the model you can 'fake' the effect by enabling the separate Reflection IOR for the glass material and setting the value higher - to 2 even 3 in some cases.

Regards,
Konstantin