ACEScg in new VFB and sRGB display.

[wyszolmirski]

Hey Guys,

Let's talk about ACES.

Short story:
I want to be able to save sRGB display correction when using ACEScg rendering primates.

Long story:
We're using ACEScg workflow for a while. Typical setup is like this: exposure +0.75, display correction set to OCIO, conversion from ACEScg -> sRGB and "saved in image" turned on.

With new VFB it looks like we can get the same result with display correction set to sRGB and added filmic tone mapping (with space set to ACEScg). In this setup order in which corrections are being applied feels more intuitive. Curves correction could be applied after tone mapping etc.

I would like to use this setup in production, but after saving outputs I'm getting wrong colors. I need something like "save in image" option for sRGB display correction otherwise colors won't match.

Best,
Tomasz

[nikoleta.garkova]

Hi wyszolmirski

Are you using the Display Correction Exposure option? If so, this is display only, meaning it will not be saved out from the VFB (unless you copy to clipboard (ctrl+c) and paste it somewhere). You will need to add an Exposure layer, adjust the settings there and then it would save the right output. If I've not understood you correctly, please do provide some more examples/screengrabs or a comparison so we can have a look. Thanks!

[wyszolmirski]

HI nikoleta.garkova

This has nothing to do with exposure. It just doesn't save in image what's displayed with sRGB Display Correction - http://www.dabarti.com/screens/s6e31...9d5bd027bQ.jpg

It saves the image without any corrections instead. Typically with just gamma 2.2 applied (or whatever is set in 3ds Max settings) - http://www.dabarti.com/screens/s0a79...5e931aa32o.jpg

As far as I understand, currently when V-Ray is set to ACEScg rendering RGB primate and display is set to sRGB (default) it converts the colors from ACEScg to sRGB for display. This is great, simplifies the workflow in general. But it doesn't save sRGB display in image and that's what I'm asking for.

I need something like this - http://www.dabarti.com/screens/s8b33...dddb3b653t.jpg for the sRGB display correction.

Scene: http://www.dabarti.com/screens/teapots.zip

Best,
Tomasz

[vlado]

As you suggested, we should add option to the "Display" layer to save the correction to the image so that the ACEScg -> sRGB correction is burned in.

Best regards,
Vlado

[wyszolmirski]

As you suggested, we should add option to the "Display" layer to save the correction to the image so that the ACEScg -> sRGB correction is burned in.

Best regards,
Vlado

Exactly. Once that's there the whole ACEScg workflow with V-Ray will get easier. No need to download OCIO.

Overall I'm extremely happy with what's been done so far to make the whole ACES experience as easy as possible. Great job!

vlado - side question, converting textures at render time adds some computing cost, so I would like to convert them beforehand and it seems there is a cmd tool for that: "ocioconvert". Is there a chance you guys could precompile it and post as "Misc Tool" for everyone to enjoy? https://docs.chaosgroup.com/display/VMAX/Misc+Tools

Best,

[vlado]

side question, converting textures at render time adds some computing cost

The cost is actually negligible (just a matrix multiplication), but I agree that it might be more convenient to convert the texture once (hopefully with proper naming ), rather than trying to remember to do it every time.

I would like to convert them beforehand and it seems there is a cmd tool for that: "ocioconvert". Is there a chance you guys could precompile it and post as "Misc Tool" for everyone to enjoy? https://docs.chaosgroup.com/display/VMAX/Misc+Tools

I guess we could, I will make a note to look into it.

Overall I'm extremely happy with what's been done so far to make the whole ACES experience as easy as possible. Great job!

Really glad to read this

Best regards,
Vlado

[StateofArt]

Hi there!
Regarding this topic, I'd like to suggest you a video made by Enrico from the SoA Academy team as a contribution to the AcademyDays2020 the architectural visualization event which was online this year. We tried to dive into this topic which is quite waste, giving an easy and correct overview and setup on the ACES workflow with V-ray5.
The video is on the on-demand page of the AcademyDays2020 here https://www.stateofartacademy.com/co...emy-days-2020/ and you need register at the event, for free. You'll get the access to all the contents from our fantastic contributors.
The event has been created to raise funds for ICRC and support its campaign against COVID-19. So if you find interesting the contents I encourage you to donate at this link https://www.icrc.org/en/support-us/o...9-academy-days
Even a small contribution can make a difference and give relief to the most vulnerable.
Thanks a lot and please send us your comments or questions. We'll be very happy to reply.

Gianpiero Monopoli
V-ray Mentor at SoA Academy

[piotrus3333]

HI nikoleta.garkova
I need something like this - http://www.dabarti.com/screens/s8b33...dddb3b653t.jpg for the sRGB display correction.

you can save with “convert to sRGB” with LUT layer in VFB2.
display correction: none
LUT layer: load lut that does nothing, saved from frame buffer with no corrections - back in a day when you were able to do it (yes, slight dig heh)

I used that to get log colour from VFB. looks like it’s working with acescg >> srgb as well but as Im not using acescg I might have missed something.

edit: save with gamma 1 in 3dsmax

[wyszolmirski]

The cost is actually negligible (just a matrix multiplication), but I agree that it might be more convenient to convert the texture once (hopefully with proper naming ), rather than trying to remember to do it every time.

I guess we could, I will make a note to look into it.

Really glad to read this

Best regards,
Vlado

vlado I see that this option is already implemented. ACEScg workflow got even better. Thank you .

[Mikhalenko]

vlado I see that this option is already implemented. ACEScg workflow got even better. Thank you .

where is impllemented? I missed something?

[wyszolmirski]

where is impllemented? I missed something?

I've seen it in the beta nightly. Will be most likely released with new version.

Best,

[vlado]

The option to burn the ACEScg -> sRGB conversion is now included in V-Ray 5.1 (see screeshot).

Best regards,
Vlado

[Mikhalenko]

I've seen it in the beta nightly. Will be most likely released with new version.

Best,

Can you please point me out where is this option?