ACEScg scene not outputting true AP1 colour

[piotrus3333]

is it true that Vantage will render ACEScg vrayscenes from VRay but the output (even "raw" exr) will be limited to BT.709 ???

it would be contrary to what was stated here:
https://forums.chaos.com/forum/chaos...05#post1212505

but I'm trying and so far failing in getting ACEScg exr from Vantage. Everything I get is BT.709.
Colour management in 3dsMax2024 set to legacy gamma, all textures correctly tagged (colour space) via VRayBitmap.
I have 2.5.1 at the moment (not able to update but there is nothing in the full changelog)

scenes and outputs attached.

[radoslav.platikanov]

The actual .vrscene is missing, could you send it? Max files would also be helpful. It's hard to say what's going on otherwise.

The raw exr output is not limited to BT.709, it will be in the rendering color space of the scene - linear BT.709/sRGB or ACEScg/AP1. The output in the viewport however is limited to sRGB, unless you have an HDR monitor.

Vantage 2.5.2 does contain an important fix for the ACEScg support actually, but in this case with the legacy gamma color management in Max I'm not sure it's relevant.

[piotrus3333]

thank you for looking into this.

[radoslav.platikanov]

Thanks for the files. I'm getting exactly the same .exr results as V-Ray with Vantage 2.5.1.

The only thing I can see is that acescg.vantage points to the sRGB scene actually, not the ACEScg one. You can verify the color space of the current scene in File -> Scene Stats -> Scene units.

[piotrus3333]

my mistake - apologies for wasting your time. everything works as expected.

[radoslav.platikanov]

No problem, good to know it's working.

[piotrus3333]

for what it's worth - I'm attaching a lut that will help visualise aces srgb display transform in Vantage:
(not perfect - the error comes from Highlight burn behaving differently in acescg scenes)