Possible VFB bug in Max 2024

[GLASS-CANVAS]

Hi There,
I'm just going through the process of setting up Max 2024 for my company, now that the first service pack is out, and I think I've found a bug in the VFB:
When starting up Max, we have a custom MaxStart.max file that, amongst other things, has the VFB set to use OCIO and ACEScg. However in Max2024 it no longer defaults to it. The exact same file works fine in Max2023

I also noticed this happen when I sent a render to backburner from a file that had previously been worked on in Max2023. The file rendering on a render node had gone back to sRGB, which is not good at all. Can you confirm this is a bug please? And if so will there be a fix, or am I doing something wrong. Is there a possible workaround for now?

Best regards, Bill

[GLASS-CANVAS]

Confirmed it's a Max thing and not V-Ray's fault at all. To get Max 2024 to remember that OCIO is the system default you have to specifically save it into the MaxStart.max file, as detailed in this section of the help file:


What's really annoying is that you can't save this file to be backward-compatible with Max 2023. If you try to backsave it you get this message:


In our company we have a custom MaxStart file that has our Layer structure and many other settings all set up. This will be a problem as it means we can't slowly migrate people over to Max 2024 as they finish current jobs, they will have to all switch at once. I guess it's not the end of the world, but it's pretty annoying.
Thank-you for your help with this matter, Vladimir, we got there in the end!

[vladimir_krastev]

HI, thanks for posting. The maxstart.max file works for 3ds max 2023 and 2024 on my end. Are you sure you do not have anything else set, for example environment variables?

[GLASS-CANVAS]

Hi Vladimir,
No, there are no environmet variables set at all for the VFB, outside of the OCIO one. Are we using the correct version of OCIO? Is there a more recent one that you use that might be causing this?

[vladimir_krastev]

Hi, I tested aces_1.2 and after your post aces _1.0.3. Everything works as expected, maxstart.max works, env. variable works. There must be something else. If you can not figure it out I suggest we meet on a team viewer session. Please open a ticket and mention my name and paste a link to the thread.

[GLASS-CANVAS]

Ok, with further investigating I've discovered it's a bug we're having in 3ds Max 2024 itself. For some reason it's not remembering that preference to use OCIO as the Colour Management workflow, even when repeatedly setting it as the system default. Anyway, when I do switch over from Gamma 2.2 to OCIO the VFB instantly switches to ACEScg as expected. I'll have to do a bit more digging to figure out why Max isn't remembering the setting. If you know of a .ini way of doing it please let me know

[GLASS-CANVAS]

Confirmed it's a Max thing and not V-Ray's fault at all. To get Max 2024 to remember that OCIO is the system default you have to specifically save it into the MaxStart.max file, as detailed in this section of the help file:


What's really annoying is that you can't save this file to be backward-compatible with Max 2023. If you try to backsave it you get this message:


In our company we have a custom MaxStart file that has our Layer structure and many other settings all set up. This will be a problem as it means we can't slowly migrate people over to Max 2024 as they finish current jobs, they will have to all switch at once. I guess it's not the end of the world, but it's pretty annoying.
Thank-you for your help with this matter, Vladimir, we got there in the end!

[GLASS-CANVAS]

Sorry to have to re-open this thread, but as an update I've found what I think is a closely related bug:
When I send a render to the network using backburner, once again the target machine renders with the wrong Display Correction in the VFB (sRGB instead of OCIO), causing the colours to be saved incorrectly. Is this something you can reproduce at your end?

[vladimir_krastev]

Can you describe once again what are you doing?
Are you building a scene in 3ds Max 2024 with OCIO as colour management system, save and send to backburner?
If there are no maxstart scene and no environment variables both 3ds max's colour space and VFB's colour space are kept in the scene so there should be no issues.
Could it be that backburner does not support the new colour management from 3ds Max 2024?

[GLASS-CANVAS]

Can you describe once again what are you doing?
Are you building a scene in 3ds Max 2024 with OCIO as colour management system, save and send to backburner?
If there are no maxstart scene and no environment variables both 3ds max's colour space and VFB's colour space are kept in the scene so there should be no issues.
Could it be that backburner does not support the new colour management from 3ds Max 2024?

Yes, that's exactly what we're doing. The thing is, as far as I understand backburner, it just packages up your current scene with all it's assets and sends it to render on a remote computer, so as you say, all of the colour space workflow settings are saved within the scene. That's why I don't understand what's causing this information to be forgotten. Is there an environment variable I can add to the remote machine that will always force V-Ray to render with OCIO on? Or maybe there's a 3ds Max .ini setting that does something similar?

[vladimir_krastev]

Is there an environment variable I can add to the remote machine that will always force V-Ray to render with OCIO on?

Here are the environment variables for controlling the VFB.

These are for enabling the OCIO:

VRAY_VFB_OCIO – If set to 1, the OCIO button of the V-Ray VFB is automatically switched on. If set to 2, the OCIO button of the V-Ray VFB is switched off.

VRAY_VFB_OCIO_INPUT_COLORSPACE - Specify default overriding input OCIO color space. A default OCIO configuration can be specified by the OCIO environment variable.

VRAY_VFB_OCIO_DISPLAY_DEVICE - Specify default overriding OCIO display device. A default OCIO configuration can be specified by the OCIO environment variable.

VRAY_VFB_OCIO_VIEW_TRANSFORM - Specify default overriding OCIO view transform. A default OCIO configuration can be specified by the OCIO environment variable.

[GLASS-CANVAS]

Sadly that didn't work. I set the environment variable, restarted the machine, fired up the backburner server and it still rendered in sRGB

[GLASS-CANVAS]

As an update we just noticed this error in the backburner window. Probably should have noticed it before!

[vladimir_krastev]

Hi, I created a scene with the new 3ds Max's OCIO colour correction, save it and open on a different computer and it works. After that tried the same scene trough back burner and it renders with RGB. I wanted to test Deadline as well but the latest version of Deadline does not support 3ds Max 2024.

[GLASS-CANVAS]

I tested a scene with the Autodesk colour management set to Unmanaged, Gamma 2.2 and OCIO, and the V-Ray settings/frame buffer set to ACEScg/OCIO and it failed to render correctly via backburner in all 3 instances. It's looking a lot like backburner is the culprit, which doesn't make a lot of sense, but is nevertheless extremely frustrating. Until we figure out a way around it we can't network render using 2024 i.e. we can't use 2024 full stop

[GLASS-CANVAS]

Question - does the ACEScg workflow work correctly with Deadline? Is that something you can test? Because if it does, then we may have to move over to it. Right now we simply can't use Max2024 with our current pipeline