Brightness bug

[GradyDevillier]

I have a strange bug. When I change the resolution in the settings or the scale in the IPR window, the image becomes brighter. Switching to CPU doesn't change anything. Turning off OCIO doesn't help either. The latest drivers are installed. Nothing shows up in the logs. Only rebooting C4D helps.

Arnold 3.3.5/6.2.1.0
ACES 1.2
C4D S24.037

RTX 2060

Driver 466.27

[peter.horvath6V6K3]

Strange indeed. I can not reproduce it. Does it happen in a specific scene or all scenes? Does it happen without ACES? Is it related to the GPU or does the same happen on CPU? Does it become brighter and brighter as you change the scale?

[GradyDevillier]

Yes, it happens in all scenes. Without ACES, it happens too. And on the CPU, too. "Does it become brighter and brighter as you change the scale?" - No, the same constant brightness. I also noticed that if I stop the render in the IPR window, rescale, then close the IPR window, and start again, the brightness does not increase. Same with the settings - with the IPR closed, I can change the resolution without changing the brightness. By the way, in Picture Viewer the image looks fine (for C4D), as it should be. Rendering through the Arnold drivers also gives a normal image.
Installed 3.3.4 on S24.037. Same bug.
And version 3.3.5 on R23.110 works fine.

[GradyDevillier]

Also, I now noticed that if the brightness bug has already appeared, I can stop the render in IPR, rescale, close the IPR window and run it again, then the brightness returns to normal.

[peter.horvath6V6K3]

Ok, I can reproduce it in S24. I start to investigate, something must have changed or it's a bug in S24. Will keep you updated.

[peter.horvath6V6K3]

It feels like a bug in S24, so I'm going to report it to Maxon. Meanwhile I have a workaround which seems to fix the issue, so I'll probably release it in the next few days.

[baumannBMMGB]

Same problem here. Only happens with colormanagement (ACES 1.2) and with CPU.

[GradyDevillier]

I will wait. Thanks!

[peter.horvath6V6K3 · Accepted solution]

The fix is released in C4DtoA 3.3.5.1.