Production Render brighter than Interactive Render when using Section planes

[manishpaul_simon]

Hi,

I've been facing this problem for quite some time now and I can't figure out why. But the Production render comes out 2x brighter than the interactive render when I use section plane with the "Affect Light" parameter turned off.

The attached renders use the default settings with RTX turned on. I get the same result with CPU mode as well.

But when I don't use section planes, the lighting remains the same between production & interactive renders.

Also, please note that I do not have any reversed faces inside the scene and it is using the default SketchUp material.

Hoping to find a solution to this. Else, I will have to get rid of the section plane workflow.

[nikoleta.garkova]

Hi manishpaul_simon,

Which V-Ray version is this? I see no difference between Interactive/Production rendering, as in the attached screen recording: http://ftp.chaosgroup.com/support/sc...5_14-54-17.mp4
What happens if you switch from RTX to CPU for example - is there any difference?

[manishpaul_simon]

Hi Nikoleta,

Thanks for getting back.
It worked for you since you did not have the "Affect Light" settings turned off in the Asset Editor.

I'm working with the latest vray version. I have recorded my version of the workflow for your better understanding.
https://youtu.be/vM652G3fOLs

Hope you guys can help me with this problem or suggest an alternate workflow.

Thanks & Regards,
Manish

[manishpaul_simon]

Hi,
This is with the CPU mode on
It's still the same result

https://youtu.be/zd_0y-gp7zE

Also, I have no idea why it's turning black after I stop the interactive render.

[nikoleta.garkova]

Hi manishpaul_simon,

Check if the material you're using in this particular project is with a pure white color. IPR is rendering with Brute Force/Brute Force, while by default, Production is using Brute Force/Light Cache. Using LC on pure white materials can cause such overexposed result; see if changing the color (i.e. RGB: 0.85, 0.85, 0.85) makes any difference.

[manishpaul_simon]

hI nikoleta.garkova

Thanks for getting back.

I did check with your suggested RGB values. It's still the same.

I guess it's got to do with the different render engines. Thanks for your support.

Best Regards,
Manish Paul Simon

[konstantin_chaos]

Hi manishpaul_simon,

I was able to reproduce the described behavior and it looks like a bug.
The difference is due to the Light Cache GI combined with the Affect Lights option.
And there is an additional issue when the walls are using the default SketchUp material.

We'll investigate both and try to improve the behavior.
Thanks for bringing our attention to this.

Konstantin