Linear, ACES and OCIO

Tue Jun 02, 2020 10:02 pm

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

yes, but this thread is about the test made with 2020.1

did you manage to get some good results with passes?

Tue Jun 02, 2020 10:54 pm

charlieL wrote:
xplorer wrote:Hello ! ACES is now in Octane did you do some tests already ?
yes, but this thread is about the test made with 2020.1
did you manage to get some good results with passes?

Not yet, i was advised to wait for the 2020.2 version + i first had to understand how to get a correct lwf EXR workflow.
For ACES .. i navigate a bit blind .. as i'm not totaly sure how to handle the ACES EXR LWF 32 bits properly into Affinity photo or else.
I'm still on 2020.1 obviously. How did this work for you ? And how did you proceed if i may ask ?

Fri Jun 05, 2020 8:27 pm

xplorer wrote:
charlieL wrote:
xplorer wrote:Hello ! ACES is now in Octane did you do some tests already ?
yes, but this thread is about the test made with 2020.1
did you manage to get some good results with passes?
Not yet, i was advised to wait for the 2020.2 version + i first had to understand how to get a correct lwf EXR workflow.
For ACES .. i navigate a bit blind .. as i'm not totaly sure how to handle the ACES EXR LWF 32 bits properly into Affinity photo or else.
I'm still on 2020.1 obviously. How did this work for you ? And how did you proceed if i may ask ?

Ho yes? I can't get the passes to work properly

I dont know if you can work with ACES within Affinity photo... from what I read they already have OCIO implemented. so that should give you the ability to work with ACES files.
it is doable in Photoshop with quite a lot of effort , ( i did not try it myself though) you can check it herehttps://community.acescentral.com/t/ace ... flows/1369

Fri Jun 05, 2020 8:54 pm

Ho yes? I can't get the passes to work properly
I dont know if you can work with ACES within Affinity photo... from what I read they already have OCIO implemented. so that should give you the ability to work with ACES files.
it is doable in Photoshop with quite a lot of effort , ( i did not try it myself though) you can check it herehttps://community.acescentral.com/t/aces-photoshop-friendly-workflows/1369

At least, just to be sure, do your LWF 32 passes NON ACES work correctly ?
well, i hear a lot about OCIO but i admit i'm not sure what it is exactly.
thanks for the link ! that should be a nice read.

One point that seems crucial is : what kind of textures should be used in the input ... what color space and gamma etc for ACES workflow ...
my tests with 16 bits textures with a gamma of 1 instead of 2.2 ( as recommended somewhere or in somediscussion ) already didn't really work, for a "simple" 32 bits LWF. hazy subject i think.

Wed Jun 10, 2020 1:06 pm

ACES is implemented but OCIO is not yet.
Without OCIO you are flying blind since you cant see how the ACES image translates to a normal sRGB LUT.
For this you would currently need to render it and import it into a compositor and view it there, which is a bit dumb.
So its not yet fully implemented.

Mon Jun 15, 2020 7:47 am

DinoMuhic wrote:ACES is implemented but OCIO is not yet.
Without OCIO you are flying blind since you cant see how the ACES image translates to a normal sRGB LUT.
For this you would currently need to render it and import it into a compositor and view it there, which is a bit dumb.
So its not yet fully implemented.

Building on your premise - you're saying that ACES in Octane works perfectly, only we can't observe it directly in Live Viewer. So if I throw my ACES output into Nuke (properly set to OCIO) I should be able to view the render in correct ACES look in Nuke viewport?

Mon Jun 15, 2020 12:03 pm

From what i understand, it requires at least an ACES2065.1 config profile file, to set your software's input. Here with Affinity photo you have OCIO, and you can set it up :

https://affinity.serif.com/fr/tutorials ... 297059572/

But i can't find this ACES2065.1 config file, to upload it in affinity ...

Mon Jun 15, 2020 6:32 pm

Great read here !

https://chrisbrejon.com/cg-cinematograp ... stem-aces/

among many things, we should render in ACEScg rather than in ACES2065.1 . ( it's explained why ) .

the srgb and Linear textures need an IDT ( Input design transform ) to convert it to ACEScg.

a proper monitor ... able to display something like DCI-P3

and of course, some display transforms.

BUT ..... Octane doesn't have an IDT feature, no display transform for ACES, no ACEScg.
There are exemples in the article done with Guerilla render, which i don't know .. but it has these features.

Mon Jun 15, 2020 7:32 pm

Octane is a spectral rendering engine. ACEScg is specifically designed for RGB rendering engines, not spectral engines. As such, the ACES2065.1 container may be a better choice for now.

As anyone currently investigating ACES may realize, and this thread itself shows, ACES is a murky topic and clear cut workflows with regard to rendering are still coalescing.

Mon Jun 15, 2020 7:41 pm

jayroth2020 wrote:Octane is a spectral rendering engine. ACEScg is specifically designed for RGB rendering engines, not spectral engines. As such, the ACES2065.1 container may be a better choice for now.

As anyone currently investigating ACES may realize, and this thread itself shows, ACES is a murky topic and clear cut workflows with regard to rendering are still coalescing.

Yes ... how long does it take to research a complete workflow with ACES .... Not everybody has the time for it. I wish that Otoy will work on it and show some video tutorial, from the pre render : texture managment, to the work in post in various softs, including affinity photo if possible. and all the tools needed to handle ACES properly.