Glossy transluscent and grass

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wasd
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Glossy transluscent and grass

Post by wasd » Mon May 14, 2018 1:36 pm

I have a question about glossy translucent material. I am trying to make grass, but wiki has very little information on how to use this material. And what troubles me the most is that part of grass just disappear. The first screen is glossy material and the second is glossy translucent.
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ss1.png
ss2.png

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Dade
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Re: Glossy transluscent and grass

Post by Dade » Mon May 14, 2018 3:48 pm

wasd wrote:
Mon May 14, 2018 1:36 pm
I have a question about glossy translucent material. I am trying to make grass, but wiki has very little information on how to use this material. And what troubles me the most is that part of grass just disappear. The first screen is glossy material and the second is glossy translucent.
Too much transmission ? Have you tried to use a darker color ?
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B.Y.O.B.
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Re: Glossy transluscent and grass

Post by B.Y.O.B. » Mon May 14, 2018 3:48 pm

Can you upload the scene?
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wasd
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Re: Glossy transluscent and grass

Post by wasd » Mon May 14, 2018 3:59 pm

Dade wrote:
Mon May 14, 2018 3:48 pm
Too much transmission ? Have you tried to use a darker color ?
The same with pitch black.

wasd
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Re: Glossy transluscent and grass

Post by wasd » Mon May 14, 2018 4:03 pm

B.Y.O.B. wrote:
Mon May 14, 2018 3:48 pm
Can you upload the scene?
Yep.
And two more shots with a little different angle of view. One has grass disappeared, other has not.

If it matters, HDRI is green point park 8k from hdrihaven.
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machine-le-grass-test-b.blend
(1.59 MiB) Downloaded 6 times
Скриншот 2018-05-14 20.05.36.png
Скриншот 2018-05-14 20.05.48.png

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B.Y.O.B.
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Re: Glossy transluscent and grass

Post by B.Y.O.B. » Mon May 14, 2018 4:30 pm

When you turn around it with viewport render running, you can see it flicker.
Weird problem.
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Dade
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Re: Glossy transluscent and grass

Post by Dade » Mon May 14, 2018 4:38 pm

B.Y.O.B. wrote:
Mon May 14, 2018 4:30 pm
When you turn around it with viewport render running, you can see it flicker.
Weird problem.
Scene size :?:

Max. path depth :?:
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wasd
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Re: Glossy transluscent and grass

Post by wasd » Mon May 14, 2018 4:43 pm

It also depends on normals direction. It's either left side, or right side which disappear (depending on normals direction). Left/right side of the screen, not the side of the bush.
Attachments
Скриншот 2018-05-14 23.38.00.png
Скриншот 2018-05-14 23.38.07.png
Скриншот 2018-05-14 23.38.42.png
Скриншот 2018-05-14 23.38.37.png

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B.Y.O.B.
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Re: Glossy transluscent and grass

Post by B.Y.O.B. » Mon May 14, 2018 5:46 pm

I have tried different epsilon settings, or deleting the (large) ground plane, but it does not help.
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Dade
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Re: Glossy transluscent and grass

Post by Dade » Mon May 14, 2018 6:54 pm

wasd wrote:
Mon May 14, 2018 4:43 pm
It also depends on normals direction. It's either left side, or right side which disappear (depending on normals direction). Left/right side of the screen, not the side of the bush.
Oh, aren't they solid ? There may be a mess with inside/outside volumes. Glossy translucent material is like glass, it assumes to enclose a volume and has different behaviors when a ray is going from outside to inside and vice versa. I think this is the source of your problem.

Have you tried to use normal glossy + transparency ? Transparency is a property common to all materials. It also a lot faster to render than glossy translucent material.
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