Hello,
I'm trying to set up ACES workflow properly.
I have OCIO env variable set up, the render view is in ACES.
However from what I understood the textures have to preconverted to ACEScg lut too, to prevent unwated oversaturation.(source [cgrenderdna.blogspot.com])

Because I'm using Renderman I cannot use OCIO Color Transform VOP node like I would in Mantra, but I have to preconvert the textures.
I can do that in NUKE or Affinity Photo but that's not really convenient for updaing lots of textures all the time.

Some command line tool woul be the best, but i found nothing on OCIO in iconvert documentation.

Anyone knows a way how to do this?

Thanks a lot!

Solved it! For anyone who might have the same problem:

VOP COP2 filter can do the job.



For sRGB images either linearize in the file node or use Utility-sRGB-Texture as “from space” in the ocio_transform. (not sure which one is better)

Now just need to automate it a bit with python..

Thanks for the post, I had the same issue in one of my projects, the only thing to watch out is that Utility-Linear-sRGB is the preset for Linear images, if you use texture in 8bit or 16 bit, you will need use preset Utility-sRGB-Texture

source https://cgrenderdna.blogspot.com/2018/06/how-to-use-acescg-in-arnold-for-houdini.html [cgrenderdna.blogspot.com]

Hello,
thanks for this post,
i've made my testings on my side,

In the case of an 8 bit srgb image file
in the file node in cop check linearise non linear images,
this will make your 8bit a 16bit / then do a vopcop2filter
> Utility - Linear - sRGB conversion to ACES - ACEScg : just as previously mentioned.

If you don't linearise what happens is that your 8bit stays 8bit,
so for example if you try to put a gamma correct node after the conversion,
colors will be clamped and saturation will touch the sky > not be relevant anymore.
(That's what may happen if an intense light is close to this texture).

If you don't want to linearise, put your file node then a convert node
to convert 16 bit then apply the conversion to acescg as previously mentioned.
( Or make your own by down “fstopping” + up ‘fstopping" the duplicated file manually
and then do a fusion hdr in photoshop, that may help to fake the 16-32 bit look
with an 8bit file but that’s out of topic).

Hope it helps,
++

kubo-von
Some command line tool woul be the best

There is ocioconvertfrom the OpenColorIO package:


For example:

pabcou

kubo-von
Some command line tool woul be the best

$ ocioconvert diffuse.tif srgb_texture diffuse.exr acescg

Can you explain a little more, its an advanced topic, but i want to learn how to use the command line to convert to accescg. Thanks