Gamma issue with viewport rendering

[John_Do]

Hi,

I've just upgraded to C4D 2025.1.3 from 2024.5 and use Corona 12.1H1, but I have something like a gamma issue when rendering in the viewport compared to the VFB :



I'm not using OCIO and have reset the render settings. The problem doesn't occur with Viewport IR.
Scene is attached.

[John_Do]

Am I the only one having the issue ?

[burnin]

Hey, no issue here.
R 2024 w/ latest daily

See, if you got "Use Cinema 4D color space" on (checked in Preferences/Renderer/Corona). 

[John_Do]

Thanks for the feedback, but I have the issue on R2025 only, 2024 is fine on my side too.

[bnji]

Hello @John_Do


Thank you for posting.
Could you please double-check if the Linear Workflow (LW) is enabled for your viewport?
(see attached image)
If not, please enable it and see if the issue persists.
Let us know the outcome.
Looking forward to hearing from you.

[John_Do]

Hey Benjamin,

Every is default here, nothing has changed in my workflow from the 2024 version.



Issue occurs only in the viewport, VFB output is fine.

[maru]

@John_Do - did you make sure that the viewport setting from Benjamin's last screenshot is enabled? (not the Corona setting but the C4D viewport setting)
Also, are you using a wide-gamut monitor? I don't think this is related, but maybe something we could check.

[John_Do]

Hi Maru,

Yes it's enabled, everything is default regarding color management on my side. I don't have a fancy monitor, just a Dell with classic sRGB coverage. Settings are identical between 2024 and 2025, yet the viewport rendering seems to lack a 2.2 gamma transform.

Just tried to switch from my custom startup scene to a blank one but the issue persists :



You guys don't have the issue ?

[bnji]

Hello @John_Do

Thank you for your reply.
I just want to be sure your "Linear Workflow Shading" is enabled for the Viewport.
You sent a screenshot of the Corona Preferences (use C4D color space) and the C4D built-in Color management options (sRGB linear workflow), but could you please double-check the setting I was talking about? It's in the "Options" menu for the Viewport.
If it's disabled, please enable it and see if the issue persists.
Looking forward to hearing from you.
Kind regards.

[John_Do]

Hey Benjamin,

Sorry I wasn't really clear in my previous message, already checked and the setting is enabled. In any case shouldn't this setting affect only the viewport shading and not the render output ?

Just tried again and although the final rendering in viewport is wrong, viewport IR gives the correct result :

[d4l1]

Is there some Post Processing Overwriting enabled in the Corona Frame Buffer? We're experiencing some difficulties with the Overwriting and Not-Overwriting of those settings. Especially when the stuff is managed via Key Frames inside the C4D scene. Only since 2025 for us too.

[bnji]

Hi there @John_Do,
Thank you for your reply.
Please consider that while the "Render viewport" tool can launch the rendering process in the viewport, its main purpose is to work with the C4D's built-in render engine (we didn't design/integrate it).
Instead, the suggested tool is to use the "Corona Interactive Viewport" since it was designed specifically to work with Corona.
On a side note, please also consider that Maxon has introduced new changes, features, and improvements (including but not limited to its new color management system), which will affect all rendering-related processes and benefit their own render engine.
I hope this helps.

[John_Do]

Hi Benjamin,

Thanks for the feedback, so to be clear what's your answer ? You guys can't fix it ? It's not in your reach ?
If so, would it be possible for you to create an equivalent command native to Corona ?

I'm using it quite a lot in conjunction with full screen mode and viewport render region. It's also useful in Camera 2D Mode. It's really nice to check some details in full res without having to deal with the VFB, moving/ resizing window, thus staying in the flow and focused.

[bnji]

Hi there @John_do,

Thank you for your reply.
What I'm saying is that we have our own solution (equivalent) for that, which is the Corona Interactive Viewport (menu Corona > Interactive Viewport)
Alternatively, you can dock the VFB window to the C4D UI; just place it wherever is most convenient for you.
Now, about the render region, the Interactive Viewport also works with the render regions in the VFB; simply define a rendering region in the VFB and then launch the Interactive Viewport.
You can modify C4D's UI to place the Interactive Viewport icon where it is most convenient for you.
I hope this helps.
Looking forward to hearing from you soon.
Kind regards.

[John_Do]

Hi @bnji,

Thanks for your feedback, but I have the impression we're running around circles here. I know very well that Corona VFB and its integration allow for the same kind of thing, I use it everyday. The thing is Cinema native rendering tools and commands are more practical and handy in some cases, allowing me to work faster without cluttering my workspace with another window.

I know it's a matter of preference and that the function is still possible with native Corona commands, but it was working and now it doesn't, so from my point of view it's a regression. The thing is I don't know if it comes from C4D or Corona so :

- Can you fix it ?
- Will you fix it ?
- Do I have to submit a request to Maxon so they fix it on their side ?

Thanks