Emission node problems

Use this forum for general user support and related questions.
User avatar
Dade
Developer
Posts: 4234
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Emission node problems

Post by Dade » Fri Oct 11, 2019 3:21 pm

We could add a "normalize" flag to blackbody texture so it may be easier to use by providing a [0.0, 1.0] values :idea:
Support LuxCoreRender project with salts and bounties

marcatore
Donor
Posts: 404
Joined: Wed Jan 10, 2018 8:04 am

Re: Emission node problems

Post by marcatore » Fri Oct 11, 2019 7:04 pm

Dade wrote:
Fri Oct 11, 2019 3:21 pm
We could add a "normalize" flag to blackbody texture so it may be easier to use by providing a [0.0, 1.0] values :idea:
In my opinion this is more useful, cause, at the end, what we need (at least me) is to have the "correct" color with a specific color temperature.
It's easier to setup a scene in that way.

User avatar
Dade
Developer
Posts: 4234
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Emission node problems

Post by Dade » Sat Oct 12, 2019 12:51 pm

I added an option to normalize BlackBody texture output:

Code: Select all

scene.textures.<texture name>.type = blackbody
scene.textures.<texture name>.temperature = 6500
scene.textures.<texture name>.normalize = 1
Anyway, you can already scale the output or set the gain to 1/89159.6 to obtain the same result.
Support LuxCoreRender project with salts and bounties

marcatore
Donor
Posts: 404
Joined: Wed Jan 10, 2018 8:04 am

Re: Emission node problems

Post by marcatore » Sun Dec 29, 2019 11:03 am

Dade, I've tested the Normalize option but there is something I cant' understand.

Using daily build.
Using an area light with "power" unit mode.
Image
Added a blackbody node to the light.
Image

Normalize OFF
Image

Normalize ON
Image


Using two area lights with "artistic" unit mode trying to match light emitted
With Normalize ON
Image

With Normalize OFF
Image

User avatar
Dade
Developer
Posts: 4234
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Emission node problems

Post by Dade » Mon Dec 30, 2019 10:50 am

marcatore wrote:
Sun Dec 29, 2019 11:03 am
Dade, I've tested the Normalize option but there is something I cant' understand.
But what is exactly that you can't understand :?:
Support LuxCoreRender project with salts and bounties

marcatore
Donor
Posts: 404
Joined: Wed Jan 10, 2018 8:04 am

Re: Emission node problems

Post by marcatore » Mon Dec 30, 2019 12:26 pm

I can't understand that you wrote "Anyway, you can already scale the output or set the gain to 1/89159.6 to obtain the same result." but, from my tests, is clearly that it's not like this.
So, if it should be the same, why the color is different if you use or not the normalize option?

And, speaking about the hue of the light, I can say that the unnormalized(but scaled as suggested) version is the color I'm expecting from a 2700°K light source.

User avatar
Dade
Developer
Posts: 4234
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: Emission node problems

Post by Dade » Wed Jan 01, 2020 12:25 pm

marcatore wrote:
Mon Dec 30, 2019 12:26 pm
I can't understand that you wrote "Anyway, you can already scale the output or set the gain to 1/89159.6 to obtain the same result." but, from my tests, is clearly that it's not like this.
So, if it should be the same, why the color is different if you use or not the normalize option?

And, speaking about the hue of the light, I can say that the unnormalized(but scaled as suggested) version is the color I'm expecting from a 2700°K light source.
This was (mostly) due to the presence of a clamp of the result between 0.0 and 1.0. I removed the clamp so it should have now the expected behavior.
Support LuxCoreRender project with salts and bounties

marcatore
Donor
Posts: 404
Joined: Wed Jan 10, 2018 8:04 am

Re: Emission node problems

Post by marcatore » Thu Jan 02, 2020 2:18 pm

Tested and now they've the same hue.
Thank you

Post Reply