Roughness different depending of C4D color management setup

[yannverbeke]

Hi,

I use ACES with OCIO for color management. Depending if C4D color management is setup as Legacy (Linear sRGB) or ACES2065-1 I get a different result in my roughness (my texture is set to non-color data and goes via a gradient).

See pictures.
Any clue why that is?

I hear two stories : for Octane always leave C4D color management to Linear sRGB (legacy), and other say use ACES. The Octane Documentation shows how to setup up ACES (complex version) and suggests to setup C4D color management to ACES.

Thanks

Yann

https://www.dropbox.com/scl/fi/34ge6fe5 ... pm0ka&dl=0
https://www.dropbox.com/scl/fi/fl70thui ... 4qr5v&dl=0

[skientia]

Any clue why that is?

1. Texture level settings.
2. The rule of thumb is: all textures are linearized since rendering is linearly calculated.
3. The "right option" depends on the texture file encoding specifications:
if it's a non-linear encoded file or linearly encoded, integer or floating point, etc. This guide covers this subject.

I hear two stories : for Octane always leave C4D color management to Linear sRGB (legacy), and other say use ACES. The Octane Documentation shows how to setup up ACES (complex version) and suggests to setup C4D color management to ACES.

There are still some misconceptions floating around, in addition to misinformed individuals spreading misinformation.
This contentious topic is for another day, but long story short: as a single individual, there are no rules when it comes to this choice.
Also, ACES has some pending flaws and AgX is the sole viable alternative, in such context.

When it comes to the "correct setup", this depends if the "color pipeline" is set to ACES. The rule of thumb remains, as it is universal: renderers calculate in-linear, thus in any 3D DCC, it is fair to assume the "correct" option is Linear. If AgX is chosen, which has a much straightforward workflow (close to load, set and done).

Octane is self "color managed", linearly calculating and as recommended, linearly encoded (with OpenEXR).
When in need of "just processing the output", it is not mandatory to load an OCIO config-file, since both ACES and AgX are natively present (built-in) in Octane. One in the Imager, the other via Octane's compositor (AOV Group System). In this case, textures are simply "converted to internal spectral calculations" and either ACES or AgX is applied in the end of the signal processing chain.

Further information: Octane "Color Management" guide and Octane ACES guide as well as other pages in the available pages and categories.