VRay ACES workflow


#1

Hi, guys,

Does anybody have the experience to setup ACES workflow with Maya 2019 and VRay Next?
I did not find any valuable information about this topic…


#2

From the ChaosGroup Forum.

The ACES workflow is currently not supported, however, we are working on its implementation. There will be official support for future V-Ray for Maya releases.

Edit:
Thats not true. It just does not work out of the box. Read below.


#3

Have a read through the below tutorial/information guide. If you are on Vray 4.2 you should be able to use the ACES workflow. FYI You need to complete the process using Nuke/Natron/Fusion or another composite software - I was unable to get this working in Photoshop.


#4

Maybe it does work like in Arnold and doing the second part in nuke like James mentioned.

https://docs.arnoldrenderer.com/display/A5AFMUG/ACES+Workflow


#5

I saw this notice that ACES currently not supported, but also Vlado mentioned that it still somehow possible.

I am on Vray Next, v 4.30.00


#6

I tried in now with Vray 4.3.001
Vray does ignoe the OCIO file.


#7

Did you load it in Preferences > Color Management?

Probably we will need to turn Color Management off completely…


#8

Im loading the OCIO file from gitHub.


#9

Right, but how you tell Maya to use the profile?
“Use OCIO config” option locked for me in Color Management window…


#10

FYI I was using OCIO 1.0.3 - AcesCG from gitHub. I got it working from 3dsmax vray 4.2 to fusion & natron. Should be the same for Nuke.

I dont use maya but it should be the same if you follow the tutorial In the link I posted above. I also referenced the information Vlado posted in the Chaosgroup link kiryha linked above regarding getting your textures/colors into the aces color space.

My point about Photoshop is that it doesnt have a good 32bit pipeline which Is why compositing software is recommended once you have it working in 3D and output your exr files for finishing.


#11

If you load the file its unlocked.


#12

Ok, I was not able to achieve any difference in render (VRay Frame Buffer) . Neither with colors, nor with lighting.

Turned off color management in Maya Preferences. Create VRay material with solid color ramp texture plugged to diffuse color. There is no difference if I pass ramp through VRayTexOCIO…


#13

Have you tried it with Arnold?
Just to be sure it does work at all.

And you cant compare it in the framebuffer.
Cause if you switch the colospace both images will be transformed.

You have to save the image to disk, switch the colorspace, save again. And open both in nuke.


#14

You should be able to see a difference in the VFB as the colors have been transformed via the IDT/Rendering Space. From the article in Maya it looks like you should be using the color management in preferences.

There seems to be a misunderstanding here about color management - the OCIO is just showing the colors in the acesCG space, you can happily switch to sRGB instead at any point. It should not affect your rendered image, your image should render out linear with no colorspace information burned in. That one rendered image file is then loaded into Nuke/Natron/Fusion and you apply the acesCG ODT so you can view it as you did in the VFB and make further adjustments from there. You can also just view this same file as sRGB instead and work traditionally. The only time something is actually changed is when you require a texture that has been created in sRGB space to be converted to Aces via an IDT (such as a Vray Color or Ramp etc).

Below is the test I did using the OCIO in the frame buffer for the ACES output.
As well as the sRGB Output instead.

VFB

ACES

sRGB

Post Production (Natron)






#15

That does not work like this in Maya and Vray.
Its fine with Arnold.

Edit: I rearead your posts above. I missed the Color conversion for Textures by Hand part.
Now its clear but a way out for a pipeline we have here.

Valdo did a summary in the Link posted above.

  1. They converted their 8-bit color textures to ACEScg but with sRGB profile baked in. When bringing these textures into Maya, they would add V-Ray texture gamma attributes to the File nodes to convert from ACEScg sRGB to ACEScg.

  2. Any other bit depth would be plain ACEScg.

  3. Any color nodes such as Ramp and VRayUserColor may have to be passed through the VRayOCIOTex texture applied to put the color in ACEScg.

  4. In the V-Ray VFB, the OCIO color correction needs to be enabled for conversion from ACEScg to ACES for display.


#16

Interesting. Then if thats the case you may have to use the same workaround that we use in 3dsmax/vray using the VFB OCIO instead - hopefully as Vlado says it will be easier in future.


#17

I am pretty sure it is working in Arnold, they have a tutorial how to set it up. Unfortunately, it does not help with VRay. And I even don`t have an Arnold…

It is a bit wired that ACES is not a standard workflow for any render engine in 2020. And its very wired that VRay for Maya does not support ACES at all.


#18

Hello all!

An interesting topic, but unfortunately there is very little information on how to properly organize the workflow for the 3dsMax + V-Ray + ACEScg. I watched a lot of videos, but in none of them I heard the answer to some questions:

  1. How to properly gamma setting in Render Setup> V-Ray> Color mapping for rendering in ACEScg?
  2. When should you enable “ACEScg primaries” in “VRayBitmap > RGB Color Space” settings? Do I need to do this if “sRGB Primaries” is selected in Render Setup > V-Ray > Color management?
  3. How to properly configure “RGB primaries” in the VRayColor map? One of the videos on ACEScg said that when you enable “ACEScg primaries” in Render Setup> V-Ray> Color mapping, you must also enable “ACEScg primaries” in the VRayColor map, and not “sRGB primaries” as in the VRayBitmap. Is it so?

Thanks!