Setup Blender 3.40 (alpha) to work with OpenColorIO-Config-ACES 0.3.0 (OCIO V2-Pre-Release)
Just in time for Siggraph there is an update to the new OCIOv2 configs.
Here is the announcement on ACESCentral.com.
I wanted 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 0.3.0 (Pre-Release) from this link
- github.com/AcademySoftwareFoundation/OpenColorIO-Config-ACES/releases/tag/v0.3.0
- This time the download contains three .ocio config files:
- cg-config-v0.2.0_aces-v1.3_ocio-v2.1.2.ocio
- reference-config-v0.2.0_aces-v1.3_ocio-v2.1.2.ocio
- studio-config-v0.1.0_aces-v1.3_ocio-v2.1.2.ocio
- Unzip and 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-beta”. In this app I use a shell script to set the OCIO environment variable and start Blender.
- This time I want to use the studio config, because it provides some camera color spaces that are not provided (and not needed) in the CG-config. But be aware that at the moment there is no IDT for the ARRI Alexa available.
MAC “Automator” script
export OCIO=/Users/daniel/MEDIA/ACES/OpenColorIO-Config-ACES-0.3.0/studio-config-v0.1.0_aces-v1.3_ocio-v2.1.2.ocio
cd /Applications/Blender/blender.app/Contents/MacOS/
./blender
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:
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.
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.
https://developer.blender.org/T96590
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.
