Linear, ACES and OCIO

[dococtane]

Hey everybody,

I know there were already plenty discussion about this topic but I still have some questions about linear workflow and ACES / OCIO. While getting into this, I came across some questions regarding this topic and probably somebody can help me with this:

1. What's the correct way of transform textures to linear? The default gamma is 2,2. According to the octane-for-C4D manual every texture needs to be converted to linear by setting the gamma from 2,2 to gamma 1,0. Does this apply on the diffuse as on grayscale maps and other maps like normal map with 8 or 16bit? Everything with 32bit (mostly exr and hdri) are gamma 1,0 by default. I tested this with a self-made texture out of substance painter which was waaaay to bright with gamma 1,0.

http://www.aoktar.com/octane/OCTANE%20H ... KFLOW.html

In this fairly old thread roeland writes that most low dynamic range images are set to 2,2 while alphas and of course exr/hdri are set to 1,0. So what's the right way?

viewtopic.php?f=21&t=33214&p=143802&hil ... ma#p143144

2. I understand that you will never get the exact same output from the LV compared to a linear render since its tonemapped. When I render out the linear exr I get pretty good results by using OCIO and converting to ICC in Affinity. Looking at Blender it seems to work a little better, as you have the ability to use OCIO right in the Viewer. I read that I can use a ACES LUT in the camera imager but the imager accepts only .cube LUTs and even with the baked "preview" LUTs it's not really usable. All the baked-in ACES LUTs expect some kind of camera input (canon, arri and so on). With octane 2020 getting OCIO support this might be no problem anymore but I can`t find the setting in the C4D Plugin. Since it`s still beta, I guess it's not included yet?

3. Regarding the ACES support in octane 2020: I`m wondering why it's ACES2065-1 instead of ACEScg and what's the purpose of the extra ACES file?

Thanks!

[nejck]

Can't answer all your questions because I'm still looking into it myself but afaik ACES will be fully implemented in the next version and not the current one. When I say "fully" I am referring to the ability to control the input and output transforms via OCIO. As of right now only the basic color management is enabled.

But really, do take it with a grain of salt and don't quote me on it. I'm still trying to figure it out myself Hopefully someone smarter will come in here and set things straight

[dococtane]

Can't answer all your questions because I'm still looking into it myself but afaik ACES will be fully implemented in the next version and not the current one. When I say "fully" I am referring to the ability to control the input and output transforms via OCIO. As of right now only the basic color management is enabled.

But really, do take it with a grain of salt and don't quote me on it. I'm still trying to figure it out myself Hopefully someone smarter will come in here and set things straight

Well, at least an answer

Thank you and good to know that the OCIO will come at some point!

[Terryvfx]

Regarding the third question ACES2065-1 = ACEScg, different name same color space.

[dococtane]

Regarding the third question ACES2065-1 = ACEScg, different name same color space.

Good to know, thanks!

[ceen]

Any news on this? Is Aces implemented in 2020? And if so how do we render it correctly?

[fatrobotsneedlove]

Reading the Octane standalone page, it appears they have only added the option to export an ACES exr. So I don't think there is a way to use ACES in the camera imager response curve, so it's not possible currently to get any visual feedback within C4D as you can in Redshift and Arnold. Unless I'm missing something?

Are you sure ACEScg and ACES2065-1 are the same thing? They are separate options in Nuke and produce very different results.

[xplorer]

Following .... i thought i had it almost right, with these steps for 32 bits LWF :

viewtopic.php?f=30&t=74331

but now you got me confused again ha ha.
But i remembered this old gamma 1 stuff for the textures , and i'd need to try again. this Roeland thread is old yes, and octane evolved a lot. So it gets confusing ... are these recepies still up to date ?

What's the interest of Aces and OCIO btw ? How do you use it ?

[calus]

Regarding the third question ACES2065-1 = ACEScg, different name same color space.

no it's not.

[xplorer]

Hello ! ACES is now in Octane did you do some tests already ?