weird volumetric lighting glitch

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Dade
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Re: weird volumetric lighting glitch

Post by Dade »

B.Y.O.B. wrote: Sun Jun 09, 2019 9:51 pm About the weird stripe: I can reproduce it even with just the volume cube and the sun. Maybe it's a bug, or maybe some other problem in the scene that I couldn't find.
I should have fixed the problem.
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FarbigeWelt
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Scattering volume: BCD succeeds where OIDN fails

Post by FarbigeWelt »

Looks like there is still a good reason to keep BCD on board of LuxCorerRender.
Scenes with scattered light, homogeneous volume or heterogeneous volume, lead on openCL to a strange distributed noise pattern even. These patterns do not disappear with 2500 samples. OIDN is currently not able to denoise these scattered patterns as shown in last post. OIDN creates organic very disturbing looking patterns.
But there are two solutions. One is to switch to BiDir, Metropolis,. Even with a noisy image OIDN makes a good result with the BiDir render.
Another one is to render openCL, what is much faster to achieve the same sample count, and use 'good old' BCD. Just switch denoiser type to BCD with default values and you get following results. Okay, BCD is slower. BCD plus openCL is still much faster than BiDir plus OIDN.
[attachment=1]Sun beam in house openCL 2500 samples OIDN 1.0. indir cache homo vol no sky
[attachment=1]Sun beam in house openCL 2500 samples OIDN 1.0. indir cache homo vol no sky
Sun beam in house openCL 1500 samples BCD 1.0. homo vol sky 2m03s denoise 18s indir cache
Sun beam in house openCL 1500 samples BCD 1.0. homo vol sky 2m03s denoise 18s indir cache
Sun beam in house openCL 1500 samples BCD 0.0. homo vol sky 2m37s
Sun beam in house openCL 1500 samples BCD 0.0. homo vol sky 2m37s
Sun beam in house openCL 1500 samples BCD 1.0. homo vol sky 3m00s denoise 21s
Sun beam in house openCL 1500 samples BCD 1.0. homo vol sky 3m00s denoise 21s
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B.Y.O.B.
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Re: weird volumetric lighting glitch

Post by B.Y.O.B. »

But isn't this result still wrong?
Look at the corners of the room - they are completely blurred.
Judging from the noisy images it looks to me like they should be sharp.

Try to use a texture on the back wall and see what the denoisers do to that.
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FarbigeWelt
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Re: weird volumetric lighting glitch

Post by FarbigeWelt »

B.Y.O.B. wrote: Mon Jun 10, 2019 10:37 am Try to use a texture on the back wall and see what the denoisers do to that.
EDIT
Instead of a texture I placed a spot light for the projection of the test picture.
Sun beam in house openCL 1500 samples BCD 1.0. test projection 8m02s denoise 1m27s
Sun beam in house openCL 1500 samples BCD 1.0. test projection 8m02s denoise 1m27s
The comparison of BCD and OIDN. BCD keeps details and flatness. OIDN creates wrinkled paper like faces and looses details.
Sun beam in house openCL 1500 samples test projection compare BCD to OIDN
Sun beam in house openCL 1500 samples test projection compare BCD to OIDN
Last edited by FarbigeWelt on Mon Jun 10, 2019 11:50 am, edited 1 time in total.
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madcat117
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Re: weird volumetric lighting glitch

Post by madcat117 »

lord Dade has blessed us once again!

cvvzoou80pp01.jpg
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FarbigeWelt
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Scattering volume: BCD vs. OIDN (2:0)

Post by FarbigeWelt »

Sun beam in house openCL 1500 samples BCD 0.0. test back wall
Sun beam in house openCL 1500 samples BCD 0.0. test back wall
Okay, the image is beside of the beam very noisy.
Sun beam in house openCL 1500 samples BCD 1.0. test back wall
Sun beam in house openCL 1500 samples BCD 1.0. test back wall
BCD detects the correct patterns in the test picture. However, the result is a bit blurry but then with this amount of noise the result is well acceptable. :)
Sun beam in house openCL 1500 samples OIDN 1.0. test back wall
Sun beam in house openCL 1500 samples OIDN 1.0. test back wall
Umpf. OIDN's algorithms got hick up by eating the openCL patterns of scattering volume. Fancy, but not very accurate. ;-)

EDIT
And this is the last image of the little investigation.
Sun beam in house, BCD openCL without indir cache 1500 samples
Sun beam in house, BCD openCL without indir cache 1500 samples
I cannot see any wrong behavior of LuxCoreRender. There is obviously everything okay from material volume to camera volume including indirect cache.
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Re: weird volumetric lighting glitch

Post by madcat117 »

I LOVE YOUR TESTS
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FarbigeWelt
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Re: weird volumetric lighting glitch

Post by FarbigeWelt »

madcat117 wrote: Mon Jun 10, 2019 3:07 pm I LOVE YOUR TESTS
Thank you a lot. You are welcome.
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kintuX
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Re: weird volumetric lighting glitch

Post by kintuX »

Still appears to be something present... :?
RAW render
Prism2CF_LC2-2b_RAW_VolumeGlitch.jpg
CONVERGENCE mix with SAMPLECOUNT
Prism2LC 00001_CONVERGENCE over SAMPLECOUNT.jpg
Scene
Prism2LC.blend
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epilectrolytics
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Re: weird volumetric lighting glitch

Post by epilectrolytics »

kintuX wrote: Wed Jun 12, 2019 9:12 am CONVERGENCE mix with SAMPLECOUNT
Very nice drawing :D

Really need to play with those AOVs more...
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