Author Topic: OCIO / ACEScg  (Read 637 times)

2025-04-17, 21:54:55

mrsacan

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Hi guys

I'm used to work on gamma 2.2 workflow and I don't use OCIO. Recently I installed 3ds Max 2025 and it says gamma 2.2 setting is legacy so I wanted to start work with OCIO (because legacy usually means at some point it's going to become obsolete and not supported), but first of all I can't get colors right (corona bitmap).
I attached some screenshots. I tried different color spaces, but it's always different.
I checked some old topics and this link : https://support.chaos.com/hc/en-us/articles/20474209561617-Color-Color-space-and-Color-Management-Basics
But I didn't able to see a solution/workflow.
I can still use gamma workflow and do my job, but I want to learn how can I setup OCIO / ACEScg correctly. Is it possible or not etc.


2025-04-18, 09:43:40
Reply #1

Aram Avetisyan

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Hi,

Which version of Corona are you using?

There were related fixes which should be in latest Corona 12 Update 2 release candidate. If possible, please try with it.
I suppose your veneer texture has nothing special and should be with sRGB primaries.
Aram Avetisyan | chaos-corona.com
Chaos Corona QA Specialist | contact us

2025-04-18, 11:19:14
Reply #2

maru

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RGB primaries set to "auto" should give you the correct results.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2025-04-18, 15:48:53
Reply #3

mrsacan

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Which version of Corona are you using?

There were related fixes which should be in latest Corona 12 Update 2 release candidate. If possible, please try with it.
I suppose your veneer texture has nothing special and should be with sRGB primaries.

12 update 1 (hotfix 1)

2025-04-18, 15:50:16
Reply #4

mrsacan

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RGB primaries set to "auto" should give you the correct results.

My last screenshot is set to auto, maybe I'm missing something else in another screen/option?

2025-04-22, 16:02:14
Reply #5

maru

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Is your texture using an ICC profile? If yes, then the issue is that 3ds Max / Corona is not ICC-aware.
Recently there was a discussion about this.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2025-04-30, 14:03:48
Reply #6

piotrus3333

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RGB primaries set to "auto" should give you the correct results.

first time loading a bitmap into CoronaBitmap follows ocio rules (sRGB by default) but then selecting Auto gives incorrect result (Linear sRGB in this case).

and why there is no "gamma 2.2 sRGB" in the drop down options? this would be the natural option to pick for users coming from old 3dsMax versions.
Marcin Piotrowski
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CGI OCIO config 04