Large difference in brightness between luxcore 2.2 and 2.3beta1

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kriscreative
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Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by kriscreative » Fri Jan 31, 2020 7:29 am

Hi there,

I've recently started using luxcore while learning architectural visualization.
I started out with blendluxcore 2.2 and recently also added blendluxcore 2.3beta1.

For some reason the render result for the exact same scene with the exact same settings is completely different between the 2 versions of luxcore. I made sure that the tonemapper is set exactly the same in both cases and auto brightness is off. For some reason the scene rendered using the beta version is much too bright.

Can anyone shed some light on what might be going on? I've gone over all settings back and forth, but all settings are exactly the same between the 2 renders.

Scene rendered using luxcore 2.2:
Image

Scene rendered using luxcore 2.3beta1:
Image

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B.Y.O.B.
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by B.Y.O.B. » Fri Jan 31, 2020 11:21 am

Light default settings have been changed in v2.3, see the last section of the announcement post: viewtopic.php?f=9&t=1738&p=19659#p19659

Note that they might change again to achieve compatiblity with Cycles/Eevee by default, so I would wait until the final release of v2.3 before porting old scenes.

kriscreative
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Joined: Fri Jan 31, 2020 7:16 am
Location: Hokkaido, Japan

Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by kriscreative » Fri Jan 31, 2020 11:32 am

I did see the note about changed light defaults in 2.3beta1 and changed them so they match the ones used in 2.2 (see my screenshots). That is unless there are some changed defaults that are not exposed to user control of course.

Anyways, thank you for the hard work! Looking forward to what the future might bring.

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B.Y.O.B.
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by B.Y.O.B. » Fri Jan 31, 2020 11:42 am

I see no light settings in your screenshots, only tonemapper settings?

kriscreative
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by kriscreative » Fri Jan 31, 2020 12:01 pm

Here are some more screenshots. It might be something obvious, but not seeing it right now.

2.2 Settings for the 3 types of light in my scene:
Image

Image

Image

2.3beta1 Settings for the 3 types of light in my scene:
Image

Image

Image

kintuX
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by kintuX » Fri Jan 31, 2020 11:59 pm

maybe changes in image pipeline/ camera settings got smthng to do with it...

chafouin
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by chafouin » Sat Feb 01, 2020 12:57 am

As far as I know, nothing in the image pipeline changed except for the auto brightness being off by default and the gain being set to 1 by default. Since your settings are identical there, it should be fine.

If there is a brightness change in the lights, then it's a bug. I haven't noticed it for lights but maybe it only affects emission nodes, I'll have a look.

Thanks for reporting.

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B.Y.O.B.
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by B.Y.O.B. » Sat Feb 01, 2020 1:00 am

It would be good to have a scene to reproduce the issue.
Maybe it's related to the fix of gain + power/efficacy settings?

chafouin
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by chafouin » Sat Feb 01, 2020 1:26 am

I want to say that it should not have affected light brightness if normalize by color luminance is unchecked.

We should have a test scene indeed.

kriscreative
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Re: Large difference in brightness between luxcore 2.2 and 2.3beta1

Post by kriscreative » Sat Feb 01, 2020 3:17 am

Test scene: https://1drv.ms/u/s!ApNar2nYtQJJhcd5-_I ... g?e=zxFJaX.

Scene contains 3 types of light:
HDRI Environment Light / Mesh light / Area lamp.
Each of the lights is in a separate light group.
HDRI Environment light and mesh lights seem to be experiencing the increased brightness.
Area lamp brightness does not change.

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