Make Filmic tonemapper desaturate bright colors (like ACES)

[atirut-w]

Describe the project you are working on

N/A. Applies to projects with realistic graphics

Describe the problem or limitation you are having in your project

Currently in both the master branch and 3.x, only the ACES tonemapper has gotten the "fitted" treatment while Filmic stays the same. I can see some people prefering Filmic over ACES since both can be used for more realistic colors with Filmic being on the brighter side.

For details about Filmic, see Color Grading and Filmic Tonemapper(Unreal Doc)

Blender reference:

Comparison of ACES and Filmic in 4.0
ACES:

Filmic:

Same comparison in 3.x
ACES Fitted:

Filmic:

Describe the feature / enhancement and how it helps to overcome the problem or limitation

The Filmic tonemapper should desaturate very bright colors, which help projects that have realistic graphics where ACES may not be a good option since it is significantly darker than Filmic.

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

N/A. No idea how tonemapping math works.

If this enhancement will not be used often, can it be worked around with a few lines of script?

Rendering is core.

Is there a reason why this should be core and not an add-on in the asset library?

See above.

[Calinou]

See godotengine/godot#52476 and godotengine/godot#52477.

cc @Lauson1ex

[ettiSurreal]

I am pretty sure that is just an issue with Filmic as a whole. Note that the author of Filmic has made a new version of it called AgX (https://github.com/sobotka/AgX), which i hope will soon be implemented into Blender, effectively replacing Filmic (which is planned to be kept for compatibility). We could potentially take a similar route and deprecate Filmic in favor of it.