White balance: how should work in luxcore?

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marcatore
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White balance: how should work in luxcore?

Post by marcatore » Sun Dec 29, 2019 10:32 am

I'm trying the new white balance camera option and I'm quite confused how it works here.

Considering a super simple scene. Default Blender scene. A plane, a cube, a camera and an area light.
No environment lighting, just one light source (the area one).
Plane and cube have a default luxcore material (white material)
Add a node to the area light and input, as color, a blackbody node with a value like 2700.
The viewport rendering is now yellowish.
Select the camera
Activate the white balance.
What value should I use to get a white image?

Thanks

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lacilaci
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Re: White balance: how should work in luxcore?

Post by lacilaci » Sun Dec 29, 2019 3:05 pm

Just like with a dslr you would pick a color of something that you know should appear white in the image (white wall, something neutral gray, with camera you could use a color checker board)

White balance for camera is useful. But since this is cg, you might be best off keeping your lights neutral white and only play with light temperatures if you are simulating some specific light source or want to establish some mood.

Anyways for archviz purposes I would stay as close to neutral lights as you can and only correct balance if some object casts a lot of color in the scene (for example saturated floor or wall...)

marcatore
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Re: White balance: how should work in luxcore?

Post by marcatore » Sun Dec 29, 2019 4:41 pm

You're right but I'd like to use real light temperature as much as possible and I'd like to have a reliable way to white balance correctly.
I really like the opportunity to setup my scene starting from a "as much real values as possible" setup and then make some "unrealistic but a bit artistic" tweaks that cg luckly permits.

At the moment, as my tests, with a 2700°K color light temperature is not possible to white balance the image.

But I should wrong with my setup, so I'd like to hear something by anyone had used this feature.

chafouin
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Re: White balance: how should work in luxcore?

Post by chafouin » Mon Dec 30, 2019 8:58 am

lacilaci wrote:
Sun Dec 29, 2019 3:05 pm
Anyways for archviz purposes I would stay as close to neutral lights as you can and only correct balance if some object casts a lot of color in the scene (for example saturated floor or wall...)
It depends what kind of environment you are rendering, really. Exteriors or sunset lighting benefit a lot from using real light colors and camera white balancing.

marcatore
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Re: White balance: how should work in luxcore?

Post by marcatore » Thu Feb 13, 2020 11:07 pm

In my opinion this feature is broken or I can't understand how to use it.

Anyone is using it?

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lacilaci
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Re: White balance: how should work in luxcore?

Post by lacilaci » Fri Feb 14, 2020 6:11 am

marcatore wrote:
Thu Feb 13, 2020 11:07 pm
In my opinion this feature is broken or I can't understand how to use it.

Anyone is using it?
No, I balance lights not camera...
But I tried it and it is bad. It should inverse the value you input to make given value white not set everything into the value. So in theory you need to invert the value you are trying to set but that won't work cause you can go max to 10K which isn't enough to counterbalance the value you tried(2700). On top of that there isn't any tint control and no colour picker... So yeah, it's pretty useless.

If you really need this feature the photographer addon has it working well and also has a picker + other controls.

Overall I have to say the imagepipeline in camera needs to be redone from scratch. The only working feature is abberation

Bloom looks horible and cannot be used for any purpose
vignetting looks bad and has just a single control
Mist can cause artifacts, it's unreliable
Film simulation has no controls over how strongly they affect the image and also kinda look weird
and yes that white balance is better to avoid.

chafouin
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Re: White balance: how should work in luxcore?

Post by chafouin » Wed Feb 19, 2020 5:10 pm

I think Octane is a good example of Image pipeline done right. The combination of tonemapper, glare and film look gives a nice cinematographic feel out of the box, which convinced a lot of artists to switch.

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Sharlybg
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Re: White balance: how should work in luxcore?

Post by Sharlybg » Thu Feb 20, 2020 11:29 am

chafouin wrote:
Wed Feb 19, 2020 5:10 pm
I think Octane is a good example of Image pipeline done right. The combination of tonemapper, glare and film look gives a nice cinematographic feel out of the box, which convinced a lot of artists to switch.
I will add fstorm /Corona
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