Eliminating weired double reflections (Sun Sky System)

[Refracty]

Eliminating weired double reflections by introducing double sided material option (off).

As we all know using transparent (glass) objects like windows while using the Sun/Sky system creates problems.
The specular material doesn't let through the sunlight and if you manually decrease the opacity to lets say 0.2 there will be weired double reflections.
Bidirectional pathtracing could be a solution for the future but it will definately take time to implement.

So wouldn't it be quite simple to implement a double sided "on/off" option (boolean) within the material node?

If you model a window (real volume with thickness) we would get rid of the double reflections because the backside of the window wouldn't be visible (flipped normal).
So no more clien't complains about weired reflections on windows when using Sun/Sky

[monkeyjet]

That's a great idea.
I never had problem since I always model glass profile to get good refraction, but for whoever doesn't, that is good to have.

[Proupin]

I've asked for this countless times! (well, only once actually, but it felt intense) it would be awesome for glass-liquid interactions, and unwanted double contributions. Actually what should be done is for Octane to be aware what medium a ray has entered, let's say glass, and on its way out be aware that is re-entering air from glass. And then we could have effects such as total internal reflection (which happens when a ray is in a more refractive medium and attempts to exit in a certain angle) and other sorts of things, like preventing a ray from hitting glass twice and looking all weird. (maybe this is already implemented i dunno)

++

edit: apparently TIR is properly implemented, don't listen to me

[roeland]

Refraction doesn't work properly on semi transparent glass, you will see multiple images when looking through the glass from an oblique angle.

Some people use a semi transparent glossy material to simulate architectural glass. This avoids the problems with the double images.

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Roeland

[Refracty]

Using a glossy instead of a specular is indeed a workaround (as long as it is not about "internal refractions").
Thanks for the tip.
Refracty

[gabrielefx]

Refraction doesn't work properly on semi transparent glass, you will see multiple images when looking through the glass from an oblique angle.

Some people use a semi transparent glossy material to simulate architectural glass. This avoids the problems with the double images.

--
Roeland

but you lost refractions...
If you create an indoor glass door and you want to simulate the thick of the glass (made of a single 1cm thick glass) you should add the refraction, without this feature is impossible to see the border (edge) of the door.

edit: solved