Best noise reduction approach

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Sharlybg
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Re: Best noise reduction approach

Post by Sharlybg » Fri Dec 11, 2020 11:23 am

Are we feeding OIDN correctly in this scene ?

https://drive.google.com/file/d/1LkSh9u ... sp=sharing
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Sharlybg
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Re: Best noise reduction approach

Post by Sharlybg » Mon Dec 14, 2020 9:48 am

Sharlybg wrote:
Fri Dec 11, 2020 11:23 am
Are we feeding OIDN correctly in this scene ?

https://drive.google.com/file/d/1LkSh9u ... sp=sharing
Please Can someone download and check if this scene have OIDN passes correctly setup ?
Thanks in advance for your help ;)
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Dade
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Re: Best noise reduction approach

Post by Dade » Mon Dec 14, 2020 10:23 am

Sharlybg wrote:
Mon Dec 14, 2020 9:48 am
Please Can someone download and check if this scene have OIDN passes correctly setup ?
Yes, it does however what are you using for the rendering ? If you are using LuxCoreUI, this is running ODIN at each screen refresh (huge useless overhead). It is a lot better to have 2 image pipelines, the first one without OIDN and the second one with. So you can use the first one for screen refresh and run the second one only on demand (for screen refresh or file save).
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daros
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Re: Best noise reduction approach

Post by daros » Tue Jan 19, 2021 3:42 pm

aniway it's wired...despite feeding OIDN with normal+ albedo, which should help to maintain texture detail...It seems impossible to use Oidn for final production. Even if i increase the resolution by 8 times, as suggested by Dade, the final area of the surface is blurred by oidn. Even if i increase rendering time by 8 times the Ai doesn't gets smarter. Oidn is very destructive.
path-gpu-10min.jpg


The last picture shows an other bidir rendering engine (10 years old) on which we tried a different approach obtaining decent results. We are running the same rendering twice at half the sampling level but using a different noise seed. Then we pass the two results through a time-based video noise reduction tool (neat-video). The result is an in-between of the noise of each pixel. In our implementation the only noticeable defect is that light distribution is slightly less "evolved" because the lower sampling level. But, at higher sampling levels, it converges correctly to optimal result with no artifacts. By sure it's a silly approach but it helped us to increase rendering speed by roughly 5 times with almost no noticeable artifacts.

All tests are 3 minutes long and done on 4 Xeon Gold 6138 Cpu's


Luxcore+Oidn
lux-oidn-View-03-1200x600.jpg

Luxcore no Oidn
lux-no-oidn-View 03 1200x600.jpg

Other bidir engine with time based noise reduction.
other bidir View 03 1200x600.jpg

Anyway i want to remark the fact that a speed up in bidir is truly needed. Please help!
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Continuum
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Re: Best noise reduction approach

Post by Continuum » Tue Jan 19, 2021 11:13 pm

Just a guess, not enough pixels in the image for OIDN to distinguish features properly? Here is a 4K render (6min path tracing Blender).
oidn.jpg

daros
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Re: Best noise reduction approach

Post by daros » Wed Jan 20, 2021 1:34 pm

Yes probably...however a noise reduction algorithm is supposed to deal with the signal/noise problem.
If we have to render images at such high resultion in order to make the algorytm understand what is signal and what is noise...it means the algorhytm is cheap or at least not suitable for final production. Rendering a picture at 16 X the desired resolution means 16 X rendering time. I prefere to render at original resolution 12 times longer.

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Dade
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Re: Best noise reduction approach

Post by Dade » Wed Jan 20, 2021 2:15 pm

Have you disabled Pixel filtering in LuxCore ? Intel OIDN is trained without pixel filtering and BlendLuxCore takes care of that kind of settings.
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Sharlybg
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Re: Best noise reduction approach

Post by Sharlybg » Wed Jan 20, 2021 2:23 pm

Dade wrote:
Wed Jan 20, 2021 2:15 pm
Have you disabled Pixel filtering in LuxCore ? Intel OIDN is trained without pixel filtering and BlendLuxCore takes care of that kind of settings.
Where can we find this parameter in Blender ? And does it make sense on Bidir engine ?
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Re: Best noise reduction approach

Post by daros » Wed Jan 20, 2021 3:37 pm

Dade wrote:
Wed Jan 20, 2021 2:15 pm
Have you disabled Pixel filtering in LuxCore ? Intel OIDN is trained without pixel filtering and BlendLuxCore takes care of that kind of settings.
Yes, we have disabled the pixel filters as always wen using Oidn

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Sharlybg
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Re: Best noise reduction approach

Post by Sharlybg » Wed Jan 20, 2021 4:26 pm

daros wrote:
Wed Jan 20, 2021 3:37 pm
Dade wrote:
Wed Jan 20, 2021 2:15 pm
Have you disabled Pixel filtering in LuxCore ? Intel OIDN is trained without pixel filtering and BlendLuxCore takes care of that kind of settings.
Yes, we have disabled the pixel filters as always wen using Oidn
Ahh ok it is this same blackman harris filter stuff. i didn't see any improvement with/without. will test again and see.
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