The flickerfree animation challenge

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Dade
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Re: The flickerfree animation challenge

Post by Dade » Sun May 10, 2020 11:19 am

Dade wrote:
Sun May 10, 2020 11:08 am
mischterlampe wrote:
Sun May 10, 2020 10:57 am
Sorry, but I don't get it. Please exlude the light tracing issue here (I disabled it for this test) and just focus on the indirect cache.
This means, if I rise the threshold, more and more materials should become black. But noting happens. If I rise the threshold to 0.9, which means almost every material should be not in the cache, doesn't exclude the materials, the debug image looks the same like the threshold of 0.05. I lowered the threshold to 0.001, but the result was the same. So changing the threshold of the indirect cache doesn't do anything.
Have you disabled persistent cache ? Otherwise the cache is not re-computed.
Oh, I see, BlendLuxCore is using an hold properties name "path.photongi.indirect.glossinessusagethreshold" while the correct name is "path.photongi.glossinessusagethreshold" because the threshold is used for caustic cache too in PGI, not only for indirect cache.
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mischterlampe
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Re: The flickerfree animation challenge

Post by mischterlampe » Sun May 10, 2020 11:47 am

First problem solved :-)

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B.Y.O.B.
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Re: The flickerfree animation challenge

Post by B.Y.O.B. » Sun May 10, 2020 12:28 pm

Dade wrote:
Sun May 10, 2020 11:19 am
Oh, I see, BlendLuxCore is using an hold properties name "path.photongi.indirect.glossinessusagethreshold" while the correct name is "path.photongi.glossinessusagethreshold" because the threshold is used for caustic cache too in PGI, not only for indirect cache.
I fixed this in the addon.

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Re: The flickerfree animation challenge

Post by Fox » Mon May 11, 2020 2:13 am

mischterlampe wrote:
Thu May 07, 2020 10:54 am
Nonetheless, the caustics of the glass bottle are very weak
The sun is at scale 4. With scale 1 and clamping off, caustics are stronger.

This is Ryzen 3900x equivalent to 1 hour
Smaller Sun Sharper Caustics.jpg
Border render
border render 200kspp.png

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Dade
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Re: The flickerfree animation challenge

Post by Dade » Mon May 11, 2020 12:14 pm

Can you try to render the animation with the latest built (when it is ready, in a couple of hours) and disabling the HDR light source (i.e. with only the sun light source) ?

I may have spotted the chain of events that is the source of the problem.
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epilectrolytics
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Re: The flickerfree animation challenge

Post by epilectrolytics » Mon May 11, 2020 8:08 pm

I have now rendered the scene with latest build and HDRI, sky or no background: everything flickers.
But worse is the speed loss: feels like 10 times slower and therefore looks noisier.
0052.gif
Instead I have another suggestion.
Dade wrote:
Sun May 10, 2020 10:59 am
Knowing the average luminance of the image to render is the only Metropolis requirement but it is not a trivial one: it must be know before doing the rendering (i.e. requires the crystal ball). If the estimation is wrong the result will be brighter/darker than the correct solution.
Why not introduce a manual setting for the average luminance?
By default it should be on auto, like the previous version after issue#312 fix which was rather stable with good light, only not in difficult circumstances like Danish Mood with HDRI.
But there would be an advanced setting similar to how clamping is implemented: the auto setting is already shown as a suggestion.

This would make animations possible even with moving glass bodies, as long as the lights are not animated.
Also we could use a BiDir render to gauge the correct brightness (somehow light tracing never matched BiDir results).
And no further development time would be wasted on this topic, the old speed advantage would be back too.
Of course this would also mean adjustable caustic brightness which is biased, but so what?

BTW here is a render with LuxCore v2.2, somehow nearly no flicker:
DnMd.mov
(617.7 KiB) Downloaded 29 times

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Re: The flickerfree animation challenge

Post by mischterlampe » Mon May 11, 2020 8:24 pm

I also rendered with the latest version 41da08d
and I get flickering, too.
https://streamable.com/wsu0yd

World Setting has no light, just one sun, 4k samples.

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Dade
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Re: The flickerfree animation challenge

Post by Dade » Mon May 11, 2020 8:25 pm

epilectrolytics wrote:
Mon May 11, 2020 8:08 pm
I have now rendered the scene with latest build and HDRI
I asked to render without HDR :?:
epilectrolytics wrote:
Mon May 11, 2020 8:08 pm
Why not introduce a manual setting for the average luminance?
Eh ? Do you know in advance the luminance of an image yet to render ?
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Re: The flickerfree animation challenge

Post by epilectrolytics » Mon May 11, 2020 8:46 pm

Dade wrote:
Mon May 11, 2020 8:25 pm
epilectrolytics wrote:
Mon May 11, 2020 8:08 pm
I have now rendered the scene with latest build and HDRI
I asked to render without HDR :?:
Please quote correctly:
epilectrolytics wrote:
Mon May 11, 2020 8:08 pm
I have now rendered the scene with latest build and HDRI, sky or no background
So I rendered it three times, including sun only, from which the GIF is made.
Dade wrote:
Mon May 11, 2020 8:25 pm
epilectrolytics wrote:
Mon May 11, 2020 8:08 pm
Why not introduce a manual setting for the average luminance?
Eh ? Do you know in advance the luminance of an image yet to render ?
After rendering first with auto setting the calculated luminance would be saved and shown in the UI (similar to suggested clamping value in BlendLuxCore).
Screen Shot.png
If it looks ok I switch to manual and use the saved value persistently for all further renderings such as of an animation.

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Dade
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Re: The flickerfree animation challenge

Post by Dade » Mon May 11, 2020 11:19 pm

epilectrolytics wrote:
Mon May 11, 2020 8:46 pm
After rendering first with auto setting the calculated luminance would be saved and shown in the UI (similar to suggested clamping value in BlendLuxCore).
Screen Shot.png
If it looks ok I switch to manual and use the saved value persistently for all further renderings such as of an animation.
Luminance is not constant across different frames.
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