LuxCoreRender Forums

chafouin wrote: Fri Aug 02, 2019 3:48 am They also don't have any specific units and only have a Gain setting.

Welcome chafouin, and thank you for your awesome addon!

Sun and sky in LuxCore calculate their brightness depending on the angle of the sun. The rest is real-world values, e.g. mean distance between earth and sun, power output of the sun, etc.
If you leave gain at 1 and only rotate the sun, you should get realistic radiance values for a cloudless day.

You can check the calculations here:
Sun: https://github.com/LuxCoreRender/LuxCor ... ht.cpp#L35
Sky: https://github.com/LuxCoreRender/LuxCor ... t.cpp#L160

Note: to get correct sky brightness, it's important to link sun and sky, otherwise the sky doesn't know about the sun rotation.

chafouin wrote: Fri Aug 02, 2019 6:12 am Okay I'm not sure what I did wrong, it wasn't clamped, but just started a new fresh scene and it follows the sunny 16 rule right out of the box.
So intensities seem correct, my apologies!

I'll use this as a reference then (and fix Photographer as it seems it is a couple of EV off...).

LuxCore‘s sun brightness and tone depends on suns rotation. The flatter the angle between sun‘s vector and ground is the darker and redder the light. If angle is rectangular you should get 100‘000 lux or more (sun gain 1.0).
Did you rotate the sun too much, almost ground parallel to see beams direction better?

welcome chafouin!!

I think it's important to have a camera white balance tool.
Curious to see your next steps!

FarbigeWelt wrote: Fri Aug 02, 2019 8:22 am LuxCore‘s sun brightness and tone depends on suns rotation. The flatter the angle between sun‘s vector and ground is the darker and redder the light. If angle is rectangular you should get 100‘000 lux or more (sun gain 1.0).
Did you rotate the sun too much, almost ground parallel to see beams direction better?

I think the issue was that the color management exposure (the one that I use for exposure with Photographer) wasn't set to its default, and was applied on top of LuxCore Camera ImagePipeline exposure.

Thank you for your help everyone!

It's hard to find out correct intensities for sun/distant light, hdri and local lights, and to find some sort of correlation with Cycles as well (to make the add-on work for both).

I've done a bunch of tests, I would like to continue this conversation and get some insight from you, but I don't think this is the right place:)
Could an admin give me the rights to create a thread please?

Please try again to create a new topic, it should work now.

chafouin wrote: Fri Aug 02, 2019 3:15 pm It's hard to find out correct intensities for sun/distant light, hdri and local lights, and to find some sort of correlation with Cycles as well (to make the add-on work for both).

You might want to wait for the 2.8 version of our addon, I will try to make the lights match closer to Cycles.

B.Y.O.B. wrote: Fri Aug 02, 2019 3:42 pm You might want to wait for the 2.8 version of our addon, I will try to make the lights match closer to Cycles.

That's good to hear, maybe my findings in the other thread can help you: viewtopic.php?f=4&t=1269. I will wait anyway to make the changes to my addon.
About the white balancing, would it be possible in Blender 2.8 to not have the viewport refresh everytime you change something in the property panel? Color management changes should be instant and not trigger a viewport refresh (same for the White Balance picker I have that can't be used properly).

Thanks a lot B.Y.O.B. for the great support!

chafouin wrote: Fri Aug 02, 2019 4:42 pm About the white balancing, would it be possible in Blender 2.8 to not have the viewport refresh everytime you change something in the property panel? Color management changes should be instant and not trigger a viewport refresh (same for the White Balance picker I have that can't be used properly).

Thanks for the heads-up, I fixed it.

Awesome!

B.Y.O.B. wrote: Fri Aug 02, 2019 3:42 pm You might want to wait for the 2.8 version of our addon, I will try to make the lights match closer to Cycles.

I'm curious to know what your plan is. Will you change the default luminous efficacy to 683 ?