1.4.1. Blender 3.4 alpha & OCIO v2-release

Setup Blender 3.40 (alpha) to work with OpenColorIO-Config-ACES 1.0.0 (Release)

The first release candidate for the new OCIOv2 configs are available.
Here is the announcement on ACESCentral.com.

I want to test the new config in Blender in the same way I did in the past with the OCIO V1 configs. The instructions can be found on the previous page and also here in a shortened version:

  • Download the OpenColorIO-Config-ACES 1.0.0-rc2 from this link:
  • github.com/AcademySoftwareFoundation/OpenColorIO-Config-ACES/releases/tag/v1.0.0
  • This time the download contains six .ocio config files:
  • cg-config-v1.0.0_aces-v1.3_ocio-v2.0.ocio
  • cg-config-v1.0.0_aces-v1.3_ocio-v2.1.ocio
  • reference-config-v1.0.0_aces-v1.3_ocio-v2.0.ocio
  • reference-config-v1.0.0_aces-v1.3_ocio-v2.1.ocio
  • studio-config-v1.0.0_aces-v1.3_ocio-v2.0.ocio
  • studio-config-v1.0.0_aces-v1.3_ocio-v2.1.ocio
  • Place the config in your user folder or on a server location.
  • On macOS I use Automator to create an App called “Blender_3.40_OCIOv2”. In this app I use a shell script to set the OCIO environment variable and start Blender.
  • I am used to have all the IDTs and ODTs in one config, so I am testing out again the studio-config.

MAC “Automator” script

export OCIO=/Users/daniel/MEDIA/ACES/OpenColorIO-Config-ACES-1.0.0rc2/studio-config-v1.0.0_aces-v1.3_ocio-v2.1.ocio

cd /Applications/Blender/blender.app/Contents/MacOS/


For now this did the trick and Blender starts with the new config and seems to run fine. I re-rendered the old scene I used for my Blender&ACES 1.2 setup guide and compared the two ocio-configs:

Blender 3.4 Alpha with OCIO v2 config – viewer set to Rec.709
Blender 3.40 Alpha with OCIO v2-ACES 0.2.0 config – viewer set to Rec709.

The render results are identical.

macOS 12.5 – 27″ iMac (Intel & AMD) bug

As I was setting up this test on my 2020 27″ iMac, I ran into display bug. By default the Device Display is set to “sRGB”. I rendered the first test images, and only the cyan sphere turned partly magenta somehow. I initially tested this is macOS 12.3, but the bug is sadly still persistent with macOS 12.5.

Update on the 29th of October 2022:
The bug is still persistent after updating the iMac to MacOS Ventura and check again the same blender scene with Blender 3.4 Alpha and the release version of the OCIOv2 config. I was hoping the bug could have been fixed by now, but it seems it isn’t…

Blender 3.2 Alpha running a OCIO v2 pre-release config.
Blender 3.20 Alpha with OCIO v2-ACES 0.2.0 config – viewer set to sRGB.
Blender 3.20 Alpha with OCIO v1-ACES 1.2 config – viewer set to sRGB.

With the OCIO v1 config this never happened before. This only seems to happen when the Blender “Display Device” is set to sRGB! After I tested around a bit, I found out that changing the Display Device to Rec.1886 / Rec.709 Video does the trick. The image looks fine again.

Further testing and after posting a bug report for Blender, I realized that I cannot replicate the issue on a M1-Max MBP. So maybe it’s not even a Blender but a macOS issue.


I posted this “issue” also on ACESCentral in the following thread:

OpenColorIO 2 Configs for ACES

Furthermore I found out that the PNG writer in Blender from the Render View writes out a broken image. The JPG writer works fine.

I will continue testing and looking out for other problems and issues. For now I am happy to see a modern and small config running OCIO v2 that makes the life in Blender a bit easier when it comes to selecting the right colorspaces.

OpenColorIO-Config-ACES 0.2.0 config with a limited set of colorspaces.