Improved support of max colour management

[RecentSpacesSam]

Title.

We've been playing around with AgX as mentioned in some other posts and would ideally like to make use of it in Max's color management instead of the current solution using LUTs, however Corona currently doesn't support the "OCIO - Custom Config File" option.

[Aram Avetisyan]

Hi Sam,

Better and more support of 3ds Max's Color Management menu is planned, and I will pass this to the related task too.

It is not quite a LUT, while its effect can be faked well with an LUT, the closer thing to AgX is the ACES OT.
As I understand, you are specifying AgX setup in the custom config file, and that is what you would like to be supported. It is not just about AgX itself, right?

[RecentSpacesSam]

Hi Aram,

Correct - this is more about the custom config being fully supported.

Thanks

[Aram Avetisyan]

A few simple tests were made and it seemed to be working.
Can you please send the config file, which you think is not working, so we can test it?
You can attach it here or send via submitting a ticket here: https://support.chaos.com/hc/en-us/requests/new

[Aram Avetisyan]

Update:

AgX config files were loaded into custom OCIO workflow of 3ds Max Color management, and everything worked fine - meaning it got loaded and recognized.
The main issue here still remains that Frame buffer view transform is not supported (AgX is a view transform) yet by Corona in OCIO workflow.
After frame buffer view transform implementation, which will mostly complete 3ds Max Color management support for Corona, this can be retested.

[RecentSpacesSam]

Hi Aram,

My apologies for not uploading the OCIO file - I'd changed machines my last message so couldn't find it. I believe it was the one I've attached to this post, downloaded from https://github.com/sobotka/AgX/blob/main/config.ocio.

[RecentSpacesSam]

Update:

AgX config files were loaded into custom OCIO workflow of 3ds Max Color management, and everything worked fine - meaning it got loaded and recognized.
The main issue here still remains that Frame buffer view transform is not supported (AgX is a view transform) yet by Corona in OCIO workflow.
After frame buffer view transform implementation, which will mostly complete 3ds Max Color management support for Corona, this can be retested.

We're looking forward to seeing this implemented. Recently we have been using piotrus3333's LUTs setup to achieve this and have been getting great results, but it would be nice to have it as a "set and forget" option for the rest of the team.

[piotrus3333]

We're looking forward to seeing this implemented. Recently we have been using piotrus3333's LUTs setup to achieve this and have been getting great results, but it would be nice to have it as a "set and forget" option for the rest of the team.

If you like the feel of AgX please consider checking this:
https://github.com/sobotka/AgX-Resolve
this is THE AgX by Sobotka. ocio version is the simplified one. you should be able to create better luts from this. it's based on arrilogC3 encoding so I guess as a bonus (if porting to Corona) you get an easy access to all the arri's looks library.

[RecentSpacesSam]

Sorry for the slow reply piotrus3333!

I must admit I'm not very knowledgeable on the process of creating LUTs from resolve.
Would it be a case of using Resolve's CST's to go from linear to AgX and exporting that as a LUT?

I'd definitely like to explore this more - we've been using your AgX LUT pack for a while now and have been getting some great results.

[piotrus3333]

Sorry for the slow reply piotrus3333!

I must admit I'm not very knowledgeable on the process of creating LUTs from resolve.
Would it be a case of using Resolve's CST's to go from linear to AgX and exporting that as a LUT?

I'd definitely like to explore this more - we've been using your AgX LUT pack for a while now and have been getting some great results.

Try the DCTL version of AgX first (link above). I consider it much better but this is all quite subjective. Note: DCTLs only work with Resolve Studio.

This particular DCTL only accepts Arri Wide Gamut 3 with LogC3 encoding as input - there is full drop down menu with other inputs but only this one combination works.
So your raw render from Corona would need CST from srgb linear to awg3 logC3 + AgX DCTL.
AgX DCTL will take you much farther than AgX Base (from my luts) to final look but you should still grade to taste (in LogC3, before DCTL).

Use LUT Cube Analyzer node in Fusion for lut creation.

I'm attaching a crude example (works through CineonLog - Logarythmic in Corona LUT layer so clips the highlight at 13.52 float, should be ok for typical archviz scene)
(lut needs string option, essential for Corona to turn off all the gamma shenanigans in frame buffer: float colormap.additionalGamma = -1.2)

edit: this lut takes raw render from Corona, transforms it through AgX Resolve picture formation as the author calls it to display it on srgb display adding one of Arri's looks.

I hope this is somewhat helpful.

[muoto]

Hello Piotrus,

what do you mean by "float colormap.additionalGamma = -1.2" ?
do you type this in maxcript listener ? (when i type this, i got a bunch of errors)

thanks!

[piotrus3333]

Hello Piotrus,

what do you mean by "float colormap.additionalGamma = -1.2" ?
do you type this in maxcript listener ? (when i type this, i got a bunch of errors)

thanks!

[muoto]

It would be nice to have your resolve/fusion workflow to see how you manage to create those LUT's... ;)

Between the -1.2 string, the "log" option in the vfb lut, the AgX ocio and DCTL (that i managed to install in resolve+fusion), the custom color correct node, well...it gets a little confused ;)

So when i color edit a 32bit image with Agx and dctl, i have trouble exporting to a lut to have the same result in the corona vfb

[piotrus3333]

It would be nice to have your resolve/fusion workflow to see how you manage to create those LUT's... ;)

Between the -1.2 string, the "log" option in the vfb lut, the AgX ocio and DCTL (that i managed to install in resolve+fusion), the custom color correct node, well...it gets a little confused ;)

So when i color edit a 32bit image with Agx and dctl, i have trouble exporting to a lut to have the same result in the corona vfb

well,
feel free to ask the Corona Team why things are so convoluted with luts in CIE and frame buffer: https://forum.corona-renderer.com/index.php?topic=40988.0;all

if you're on 11.1 - you can use Gamma Operator 0.455 before LUT operators and the rest of invisible gamma transforms is cancelling itself out. no need for string option and this would work in CIE as well.

Fusion exports luts only for closed domain of 0-1 float, same as photoshop and most lut tools.
Easy way of doing that in Corona is Highlight compression 999 (Reinhard tonemapper x=y/(y+1)) - it acts as your log encoding - raw render is compressed into 0-1 range and lut can access those colour easily.
So in Fusion after creating hald image you need to apply reversed Reinhard on it, convert to arri logC3 and then AgX DCTL >>> and you have a lut that does Reinhard to one of AgX DCTL displays.

what are you trying to create exactly? a macro from Fusion is of no use if you do not know the math behind.

[muoto]

From my point of view, the Agx color management is quite seducing. Nice highlight falloff, colors OK, i like the desaturated aspect as will on high values.

I most of the time use your AgX matrix (thanks) + custom 1D curve made with Lutcalc, and it works quite well.

I also tend to have little photoshop editing at the end, so i like to have my colors right in the render, and i find it very hard to finetune them in the VFB.

So i thought of finding the nice color setups with a lut in Resolve, and then bake them with AgX in one single LUT.