Author Topic: Glass does not look transparent  (Read 3183 times)

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Offline Zvi

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Glass does not look transparent
« on: May 17, 2016, 01:36:14 am »
In the attached images you can see that the glass in the front of the bottle does not look like a transparent glass, but frosted. I used full raybouncing, dielectric material with the correct definitions, and good lighting.

Offline Zvi

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Re: Glass does not look transparent
« Reply #1 on: May 17, 2016, 05:27:57 am »
I'm attaching the file of the scene itself, if someone wants to check it.

Offline Esben Oxholm

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Re: Glass does not look transparent
« Reply #2 on: May 17, 2016, 07:27:49 am »
Hi Zvi.

I had a quick look at it. I think it comes down to two factors:

1. Lighting:
Your HDRI is kinda contrastless and is especially lacking dark areas. Try using a HDRI with higher contrast and fully black areas.

2. Model and material setup:
Accurate representation of liquid inside glass containers needs a bit of (not so obvious) setup work.
You should in your CAD software split the surfaces as sketched in the attached image. The left part shows how your setup is a the moment (as far as I could see) and the right shows the ideal setup.

All three surfaces should have the dielectric material applied and be adjusted as this:
(Quoted from Dries (except from color references) from https://www.keyshot.com/forum/index.php?topic=12499.0 - Not sure why I didn't just link to this from the beginning)

Orange surface: Dielectric material. Refraction Index = 1.5 (or whatever is appropriate for your bottle's material)
Blue surface: Dielectric material. Refraction Index = 1.334 (the IOR of the liquid) / Refraction Index Outside = 1.5 (the IOR of the bottle)
Green surface: Dielectric material. Refraction Index = 1.334 (the IOR of the liquid) / Refraction Index Outside = 1 (the IOR of air)

Hope it helps.

Offline DMerz III

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Re: Glass does not look transparent
« Reply #3 on: May 18, 2016, 04:06:15 pm »
Esben, I have to draw that exact sketch out for my CAD designers every time we render some kind of glass bottle, haha.

Offline richardfunnell

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Re: Glass does not look transparent
« Reply #4 on: May 18, 2016, 06:30:36 pm »
Haha, yep, saved for future use! Thanks :D