Hey guys, I’ve been trying to wrap my head around taking a render from blender and bringing it to Nuke and keeping the same look.
As I understand it, it goes like this. From blender you output an openEXR or openEXR Multilayer, this will ignore the color management settings of view transform, exposure, gamma etc, outputting a file in Linear Rec.709. Then you bring that file into nuke, change the project settings to use OCIO as color management and use a OCIO filetransfer node to get the AgX color transform for your file that is in linear space. That’s what makes sense to me, yet I always get it looking different from what my render looked like in Blender.
I’ve watched several videos, been fiddling with OCIOcolorspace, OCIOfiletransform, tried different output settings from blender, this and that. I can never match it, which I should be able to easily no?
It even has me questioning if I have the right AgX ocio.config file, but it’s literally from Troy Sobotkas Github
Are you using the same AgX for both software? AgX which is shipped with Blender 4+ is based on the
Original AgX by Troy but it is not completely the same. Have you tried using ocio.config from the Blender installation folder?
However it looks like the config.ocio file straight from 4.1 doesn’t function here at all for whatever reason in the filetransform node. However it did slot into the colormanagment in Nuke
I also tried with a OCIOColorspace node
I tried to many options it provided for output, but again none of them seem to match
I don’t use Nuke so i can’t say for sure, but i guess some of the configurations in the Blender AgX is not supported in Nuke, as it is custom-made for Blender, i remember having the same issue in Substance Painter, so i tweaked the original AgX (or Blender AgX beta/earlier version --i forgot-- before it was integrated in Blender) config to be used in SP (i only edit the look transform, as i only need the rough estimation of the contrast).
If you think the original AgX version is enough for your needs, why don’t use it the other way around? use the original AgX in the Blender config.
Or, maybe you wanna try to use this fork of AgX GitHub - MrLixm/AgXc: Fork of Troy.S AgX by MrLixm, as he got the configuration for Nuke (but still, it is based on Original AgX, not the Blender AgX).
It does look like there’s a slight saturation difference, but exporting the Blender image and doing a difference between the results shows the images are all but identical, so it’s just something about the display process itself between the two programs? Possibly something with my P3 Mac display. Whatever the cause, I can be confident the pixel values I’m creating are the same, even if they look slightly different between the two programs for some reason.
If you’re using a color space transform inside the node graph, are you bypassing the project-level transform? The data coming out of that transform (OCIOColorSpace or OCIODisplay) is display-referred data, ready to be sent directly to the screen, but by default you’ve also got a display transform on your viewer (sRGB, rec709, whatever). If that’s still on while you’re doing that AgX transform in nodes, they’ll double up, and you’ll get a washed-out image. You can set your viewer to Raw, which will bypass that second transform, but means viewing any node other than the final color transform will look incorrect, or you can select the transform there instead of inside the node graph, applying it nondestructively on top of everything at the project level (equivalent to the way it works in Blender).
