VFB display correction reverts to aces CG without asking

[seandunderdale]

I know my VFB display colour settings arent technically correct, but I get the results I want and I dont have to fuss with calibrating backplates to work with aces. I set my Input colourspace to scene-linear DCI-P3 D65...which through trial and error I find gives me the results without hassle. Vray sends me all sorts of warnings that it isnt supported, but its fine....thing is, when I close a scene, and re-open it has unhelpfully switched my scene back to aces. Can this behavior please be changed so that whatever I set in the VFB, stays as the setting in the VFB?

Im using Maya 2022.3
V-Ray 5 for Maya, update 2.2

(v5.20.02, revision 31334 from Mar 31 2022)

[hermit.crab]

We must have missed this since it was also happening in 3ds Max. I've logged the issue (internal bug-tracker id: VMAYA-11536). The current workaround is to use the OCIO environment variables to set defaults.

[seandunderdale]

I have never used env variables before, are you able to elaborate on to set this up?

[hermit.crab]

Click the Windows key and search for environment variables. In the system properties menu (advanced tab), click on the Environment Variables button. Afterward, create a new variable by clicking "New". The variable name goes in the Name slot and the value is whichever color space you wish (you need to follow the config's syntax to work). For example:

 VRAY_VFB_OCIO_INPUT_COLORSPACE = ACES - ACEScg

[seandunderdale]

Cool! Ill try that. Thankyou.

[seandunderdale]

Does Vray have to always print the warning message that the colorspace isnt supported, is there a way to mute these warnings? I also wonder why its an option if it says it isnt supported.

[hermit.crab]

Which warnings are you referring to? This one?

 Warning: V-Ray: Failed to set Maya Color Management to convert dolbypq4000nitsshaper_ap1 to sRGB (ACES) #

This seems to be caused by the fact that V-Ray tries to match the VFB input color space to the Maya Color Management rendering space, which when using a custom OCIO config (in my test ACES), only a single option is available (determined by the rendering role in the config.ocio file itself). There's shouldn't be warnings whenever the color spaces match. I'll need to investigate more to confirm this. If you're referring to another warning, do share.

[seandunderdale]

The error I get is this
// Warning: V-Ray : Unsupported rendering color space scene-linear dci-p3 d65. I have the same colourspace set in my maya prefs as I do in the VFB.

[hermit.crab]

Well, rendering in that space is not supported (choosing it as an input space in the VFB is though), hence the warning (this is the answer to the warning message mentioned in my previous thread as well). The only supported ones are the ones you can set in the Color Mapping options (basically sRGB/Rec709 and ACES). I don't think you can mute the message.

[seandunderdale]

Ah ok...I hadnt seen the "rendering colour space" menu in the "colour mapping" drop down....I stopped looking in there once I switched to VFB tonemapping. When I switched VFB input space it changes the Maya prefs rendering space (theyre clearly linked), so I got confused when you said VFB input is fine, but rendering space isnt...but I see now I can set rendeting space in render settings color mapping...Ill try that now and see how it goes. Cheers!

[seandunderdale]

Your suggestion has fixed it. Once I changed to aces in render settings, and my usual colour input in the VFB, there's no more error warnings, and Vray seems much happier!