Glass roughness problem

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JoeDDD
Posts: 26
Joined: Sun Jan 13, 2019 8:00 am

Glass roughness problem

Post by JoeDDD »

When I try to increase the glass roughness value the edges of the object get very dark.

I am trying to get this result:
https://ibb.co/ns9CTtV



But I am getting this by using glass shader with 0.5 roughness value and homogeneos volume with red absorption color and 0.05 scatter scale:
https://ibb.co/9vcgkmx

Am I using wrong materials?
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Dade
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Location: Italy

Re: Glass roughness problem

Post by Dade »

JoeDDD wrote: Wed Jan 16, 2019 8:07 pm When I try to increase the glass roughness value the edges of the object get very dark.
Are also using a volume or not ? It may be worth trying to use glass+homogeneous volume with a lot of scattering, it may be a more accurate simulation of that kind of material.

Also, that kind of darkness,may be the result of too short paths: try to increase the max. path depth.

If you post a test scene, it will be easier to help you.
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JoeDDD
Posts: 26
Joined: Sun Jan 13, 2019 8:00 am

Re: Glass roughness problem

Post by JoeDDD »

Dade wrote: Wed Jan 16, 2019 9:46 pm
JoeDDD wrote: Wed Jan 16, 2019 8:07 pm When I try to increase the glass roughness value the edges of the object get very dark.
Are also using a volume or not ? It may be worth trying to use glass+homogeneous volume with a lot of scattering, it may be a more accurate simulation of that kind of material.

Also, that kind of darkness,may be the result of too short paths: try to increase the max. path depth.

If you post a test scene, it will be easier to help you.
TestScene.blend
(3.19 MiB) Downloaded 159 times
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Dade
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Re: Glass roughness problem

Post by Dade »

I think the material you should use is "mattetranslucent": https://wiki.luxcorerender.org/LuxCoreR ... ranslucent

Image

Roughglass is more intended for opaque glasses like the one used in bathrooms, etc.:

Image

mattetranslucent+volume as described in https://wiki.luxcorerender.org/LuxCoreR ... sion_Color should deliver the result you are looking for.

Your test scene has also a very uniform and low intensity light (i.e. sky only), I would add a sun light source (or some other kind of direction light source).
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