Env. Light Visibility Cache

Discussion related to the LuxCore functionality, implementations and API.
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lacilaci
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 6:19 am

epilectrolytics wrote:
Tue Jul 30, 2019 6:14 am
lacilaci wrote:
Tue Jul 30, 2019 4:58 am
Maybe it's some biased performance tricks or something that others do to avoid the issue or I really don't know.
Maybe in Cycles filter glossy helps with that.
Do you have reflective caustics and filter glossy activated when you render in cycles?

I never found an explanation how it actually works but I suspect it uses higher roughness for second and further bounces or something.
Even with filter glossy disabled I haven't seen any change in cycles's behavior...

Luxcore renders just fine without part of the environment/obstructions
noenviro.jpg
45sec

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lacilaci
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 6:34 am

It's the GI caching causing most of the noise.
If I lower the gi caching glossiness threshold to cover the sink as well I get this:
pgi_on.jpg
There is still some pretty bad noise over there that will take ages to clean....

maybe agressive russian roulette?

I can get pretty bad performance in cycles's reflections too if I leave defaults of min. bounces to 0 and leave cycles to automatically decide when to terminate ray. But! If I set min. bounces to the same value as max bounces in cycles, I get just a small performance hit but a lot cleaner glass and reflective shaders in interior!!!

I guess this type of stuff isn't exposed in blender? To make sure rays don't get teminated before their max depth?

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Re: Env. Light Visibility Cache

Post by B.Y.O.B. » Tue Jul 30, 2019 7:32 am

lacilaci wrote:
Tue Jul 30, 2019 6:34 am
I can get pretty bad performance in cycles's reflections too if I leave defaults of min. bounces to 0 and leave cycles to automatically decide when to terminate ray. But! If I set min. bounces to the same value as max bounces in cycles, I get just a small performance hit but a lot cleaner glass and reflective shaders in interior!!!

I guess this type of stuff isn't exposed in blender? To make sure rays don't get teminated before their max depth?
It is not exposed in Blender, we use the default values of LuxCore:
https://wiki.luxcorerender.org/LuxCore_ ... PATHCPU.22
("path.russianroulette.*")

But I can send you a BlendLuxCore version where you can use these parameters if you want to test that.
It only requires to add them here: https://github.com/LuxCoreRender/BlendL ... ig.py#L242

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Dade
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Re: Env. Light Visibility Cache

Post by Dade » Tue Jul 30, 2019 8:06 am

lacilaci wrote:
Tue Jul 30, 2019 6:34 am
It's the GI caching causing most of the noise.
If I lower the gi caching glossiness threshold to cover the sink as well I get this:
Can you post a test scene ? Just light source + walls + sink ?
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lacilaci
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 8:43 am

here, but it never gets that noisy with a basic setup as it does within "complex" environment full of obstacles.
lux_sink_only.blend
(1.96 MiB) Downloaded 16 times
The reason why I thought it is russian roulette is that it looks cleaner with low glossiness threshold for photongi, so when the sink actually uses photongi it becomes much faster to render... although some noise sill remains in the full scene...

I will try to dig through the scene, maybe there's something else that's the source of the crazy noise. Some shader settings, maybe bad normals on some objects or something(although cycles didn't have a single issue with even more complex version of the scene)

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lacilaci
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 8:57 am

B.Y.O.B. wrote:
Tue Jul 30, 2019 7:32 am
lacilaci wrote:
Tue Jul 30, 2019 6:34 am
I can get pretty bad performance in cycles's reflections too if I leave defaults of min. bounces to 0 and leave cycles to automatically decide when to terminate ray. But! If I set min. bounces to the same value as max bounces in cycles, I get just a small performance hit but a lot cleaner glass and reflective shaders in interior!!!

I guess this type of stuff isn't exposed in blender? To make sure rays don't get teminated before their max depth?
It is not exposed in Blender, we use the default values of LuxCore:
https://wiki.luxcorerender.org/LuxCore_ ... PATHCPU.22
("path.russianroulette.*")

But I can send you a BlendLuxCore version where you can use these parameters if you want to test that.
It only requires to add them here: https://github.com/LuxCoreRender/BlendL ... ig.py#L242
I did this:
rr_12.jpg
But no change in how it looks... so I guess that's not the issue here. (Unless I screwed it up :D)

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Re: Env. Light Visibility Cache

Post by Sharlybg » Tue Jul 30, 2019 9:12 am

Please what is your clamping value ?
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lacilaci
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 9:15 am

Sharlybg wrote:
Tue Jul 30, 2019 9:12 am
Please what is your clamping value ?
I tried 100000 and also 10... little to no change

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Re: Env. Light Visibility Cache

Post by Sharlybg » Tue Jul 30, 2019 9:27 am

I tried 100000 and also 10... little to no change
So what is your current lighting setup in the complexe scene and your sink max white albedo ?
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Re: Env. Light Visibility Cache

Post by lacilaci » Tue Jul 30, 2019 9:45 am

Sharlybg wrote:
Tue Jul 30, 2019 9:27 am
I tried 100000 and also 10... little to no change
So what is your current lighting setup in the complexe scene and your sink max white albedo ?
constant color background and material color is at 0.7 white and roughness at 0.02 it is as basic as it gets

I also tried octane, and there doesn't seem to be any issue with this type of stuff just like cycles.. so I'm confused.
I will watch out next time I'm building a scene for this issue and maybe figure something out, right now I have no idea what went wrong.

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