Emission node problems

[Dade]

We could add a "normalize" flag to blackbody texture so it may be easier to use by providing a [0.0, 1.0] values

[marcatore]

We could add a "normalize" flag to blackbody texture so it may be easier to use by providing a [0.0, 1.0] values

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.

[Dade]

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.

[marcatore]

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.

Added a blackbody node to the light.


Normalize OFF


Normalize ON



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


With Normalize OFF

[Dade]

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

But what is exactly that you can't understand

[marcatore]

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.

[Dade]

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.

[marcatore]

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