Distorted / Bumpy reflections on glass

[Pixelo]

Hi,
I would like to make a glass material which simulates the way reflections are distorted on glass in real life (glass panel are never perfectly flat).
I tried to add bum on my material, it's working the reflections are distorted, but the refraction also and this is not realistic.
Any idea on how i could add some bump affecting only the reflections ?
Thanks !

[rivoli]

do the windows have thickness? or are just single sided planes?

[Pixelo]

It depends... Most of the times they have thickness.
You got a solution ?
Thanks !

[simmsimaging]

Hi,
I would like to make a glass material which simulates the way reflections are distorted on glass in real life (glass panel are never perfectly flat).
I tried to add bum on my material, it's working the reflections are distorted, but the refraction also and this is not realistic.
Any idea on how i could add some bump affecting only the reflections ?
Thanks !

What about a VrayBlendMtl? Base layer has normal refraction but no reflection, and add a second layer that is additive, and make it reflective and add the bump to that layer. Should do the trick I think.

[rivoli]

I thought the effect could be exaggerated if the windows didn't have thickness.. anyway, I guess this is somehow to be expected as the bump would affect the geometry symmetrically on opposite normals, deforming it in a way which is different from what would happen in real life. just guessing here, but the solutions could be either unwrap the panels and paint some noise only on one side, or modeling them by hand..

[pixela]

I felt like you have taken my name.

[fAEkE]

Try using a very low refr IOR. You can barely see the refracttion in an ordinary window anyway.

[Pixelo]

Hi all ! And thanks for your replies. I will try your ideas as soon as i get the time.
And PixelA, very sorry i didn't knew you otherwise i would have taken another nickname !

[PIXELBOX_SRO]

I think Bertrand Benoit had this nicely done in one of his renders....

Out of topic:
lets make a PIXEL club all the member who share the similar names
When i started my company Pixelbox, i though the idea about its name was very bright )) lol....now i am not so pleased anymore )) but hey...its so common it helps with SEO

[themaxxer]

if you only want some distortion in the reflections then you have to set the IOR in efraction to 1.0 and in reflection to 1.6 (uncheck the "L") to get two different IOR's.
that should work.

best regards
themaxxer

[fAEkE]

Reflection IOR does not need to be 1.6. It probably wont look good with IOR 1.6 if it's ordinary windows. We have had some bugs with Refr IOR 1.0 aswell so I recommend 1.01. No offence themaxxer.

[trixian]

You guys are doing it in a quite complicated way. All you need to do is make sure the bump is doing the correct thing on each side of the glass. That means one side gets the regular bump, the other side gets the same but inverted. This works flawlessly for me.