Luxcore testing scene

Post your tests, experiments and unfinished renderings here.
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Zorianpl
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Joined: Tue May 25, 2021 2:34 pm

Luxcore testing scene

Post by Zorianpl » Sat Jun 05, 2021 10:52 am

Hi Luxcore render masters. I've got a few questions. Every time when I'm trying to start using Luxcore, I feel that I am hitting the wall. Many of people says, that Luxcore is superfast, but according to my tests for example Octane beats it drastically. Maybe I am using some weird settings that makes my render much slower?

My Computer specification is:

Rtx 3090
RTX 2080ti
Threadripper 3960x 24 core 3,79GHz
Ram 128GB

While in Octane, I am using only RTX 3090 for rendering.

Here below is a short animation made using Lux core render (where the caustics are not so much visible, but they are visible in caustic pass - which I increased in compositor)

https://youtu.be/t91pKu_c67c

One frame in fullhd took 7minutes and 30 seconds and the passes looks like that:

Noised image:
noise.jpg
denoised by Luxcore:
denoised.jpg
Caustics:
caustics.jpg
Denoised Caustics using Open Intel image Denoiser Node:
caustics denoised.jpg

And here are Octane outputs, rendered in 3minutes and 35s

Noised image
noised image Octane.jpg
Denoised image used Denoise node:
denoised image Octane.jpg

Here below are Luxcore settings:
settings.JPG

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Sharlybg
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Re: Luxcore testing scene

Post by Sharlybg » Sat Jun 05, 2021 8:21 pm

Hi ,
Welcome to the Luxcore comunity.

First try to match octane lighting if you want to compare ( Hdri rotation and power)
Second it look like your clamping value is unnecessary high (Suggested value is arround 0.5 and you render with 100X higher value. try something closer to the suggested value until you loose to much details in lighting quality).
Third you really don't need Light tracing to be enable for this scene i think only a white shadow color on your glass panel will make it easier to render.
Fourth for a linear lighting approach disable auto brightness in your camera setting put something default like 1 and play with your HDRi power.
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Zorianpl
Posts: 2
Joined: Tue May 25, 2021 2:34 pm

Re: Luxcore testing scene

Post by Zorianpl » Mon Jun 07, 2021 6:42 am

Hi Sharylybg

Thanks for welcoming me and your suggestions.
Sharlybg wrote:
Sat Jun 05, 2021 8:21 pm
First try to match octane lighting if you want to compare ( Hdri rotation and power)
It isn't a new project, I'm working on it quite long, and I made also versions where Luxcore scene is lightened similiar way as Octane (I didn't find any possibility to make Ray switch setup for environment, where lighting is caused by one HDRi and reflections/background by different, which is common in other render engines.) So I used Background image in camera Tab. The topic with Luxcore renders compared to the Octane renders are here: https://blenderartists.org/t/dutch-exte ... /1306520/4

Sharlybg wrote:
Sat Jun 05, 2021 8:21 pm
Second it look like your clamping value is unnecessary high (Suggested value is arround 0.5 and you render with 100X higher value. try something closer to the suggested value until you loose to much details in lighting quality).
The first test were made using suggested value, and in my opinion looked much worse, so I decided to play with this value.
Sharlybg wrote:
Sat Jun 05, 2021 8:21 pm
Third you really don't need Light tracing to be enabled for this scene, I think only a white shadow color on your glass panel will make it easier to render.
As far as I observe the world, there should be caustic on facade, especially in the shadows. Isn't this option responsible for reflection caustics? I do not need caustics from windows, only from water. Is there any possibility to render only caustics, without rendering other data?
Sharlybg wrote:
Sat Jun 05, 2021 8:21 pm
Fourth for a linear lighting approach disable auto brightness in your camera setting put something default like 1 and play with your HDRi power.
Will check it. First I had Camera settings exposures, but while testing changed it to linear.

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Sharlybg
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Re: Luxcore testing scene

Post by Sharlybg » Mon Jun 07, 2021 7:16 am

For caustics underwater you need to enable caustic cache.
Theses caustics aren't the usual one you can render with light tracing.
You just render it and make the cache persistent so that you don't to rerender it again and again.
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kintuX
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Joined: Wed Jan 10, 2018 2:37 am

Re: Luxcore testing scene

Post by kintuX » Mon Jun 07, 2021 2:45 pm

Hi & welcome.

To see, everything works fine do take a moment and test caustics & SDS paths on an example scene "Underwater Paintings".

For reflective caustics thrown on a wall from water surface check a "pool tester" scene here.

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