materials interinfluence

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blackcat
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materials interinfluence

Post by blackcat » Wed May 27, 2020 5:06 pm

I'm trying to render a scene with LuxCore for the first time since some years. The main problem for me is the noticeable materials inter-influence. In my render I would like to get the ceiling in white color throughout, but the red objects below make it reflecting red color inevitably. In Cycles I would just turn off the red objects influence. Please give me a hint how would I solve the problem the best way? Thank you very much in advance.
untitled1.png
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B.Y.O.B.
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Re: materials interinfluence

Post by B.Y.O.B. » Wed Jun 10, 2020 9:32 am

I think the only way is to reduce the path depth (bounces).
Or composite the image from AOVs (direct diffuse, indirect diffuse, direct glossy etc.) and desaturate the indirect passes before adding them all together.

Fox
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Re: materials interinfluence

Post by Fox » Wed Jun 10, 2020 11:22 am

What if you set the roughness to very high, like 0.85?

blackcat
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Re: materials interinfluence

Post by blackcat » Wed Jun 10, 2020 3:22 pm

B.Y.O.B and Fox, thank you both for the suggestions. I made a quick test playing around a bit with the red material properties and bounces. I wouldn't say any of these my tweaks has influenced noticeably the picture. B.Y.O.B. thank you for the another idea to use compositing In this case, that probably would be the best solution.
Thanks again!
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B.Y.O.B.
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Re: materials interinfluence

Post by B.Y.O.B. » Wed Jun 10, 2020 3:26 pm

If you have no other glossy materials in the scene, you could make the red roof a glossy material and set the glossy bounces to 1.

blackcat
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Re: materials interinfluence

Post by blackcat » Wed Jun 10, 2020 3:52 pm

Have tried that. You know the reddish tone is still persisting locally on the ceiling. Honestly sometimes I think about both Cycles and Lux regarding the situation. I love both renders but I can't understand why they imply such a strong inter-influence? These renders tend to be realistic, but in real life, has anyone ever seen such reflections in his room caused by the items inside it? I guess no, or at least not in such a high degree.

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B.Y.O.B.
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Re: materials interinfluence

Post by B.Y.O.B. » Wed Jun 10, 2020 10:36 pm

I'm pretty sure most renderers are correct when emulating this effect.
If the color bleeding seems to strong to you compared to real life, it might be because your material setup is different. Your materials might have much higher albedo than real materials, or your light settings or scene scale are different.
You also have to consider that your brain is applying heavy adjustments to everything you see, and can adapt to the whitepoint of many lighting conditions. Memory is also not reliable.

blackcat
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Re: materials interinfluence

Post by blackcat » Thu Jun 11, 2020 7:46 am

B.Y.O.B. thank you very much. Your answer is very helpful for me, as always, though. I see now clearly this problem occurs because of wrong settings rather than because of the render impropriety. I see I should work more with settings. Thank you again.

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