Problem with denoiser and glass

[INDUSTRIROMANTIK]

Hi!

I rendered a bathroom with a glass shower door. The denoiser makes everything behind the glass blurry. I've tested denoise render elements separately and affect all channels on the glass material witch is just standard glass.
affect all channels helped the noice but everything behind the glass got brighter. I attached a test image. Im on Maya 2015 Extension 1 + SP6 and VRay 3.40.02.



Regards

Patrik @ Industriromantik

[yolov]

Can you attach an exr or vrimg with all the channels so we can test this on our end and see what we can find?

[INDUSTRIROMANTIK]

Thanks! Here is a link to the vrimg. https://drive.google.com/file/d/0B9U...ew?usp=sharing

Regards

Patrik @ Industriromantik

[yolov]

Thanks, we'll have a look and get back to you. It seems that the denoiser fails to preserve detail through refractions in this case.
I'll let you know when there's news about this.

[vlado]

In the refraction options for the VRayMtl material, set the "Affect channels" option to "Affect all channels" and it will work better.

Best regards,
Vlado

[INDUSTRIROMANTIK]

I tried with "Affect all channels". The denoiser worked but everything in the refraction got brighter. As in the third image in my original post.

Regards

Patrik @ Industriromantik

[yolov]

Seems that there's nothing much we can do at the moment, the denoiser can't perfectly know what to denoise when there's glass (or multiple stacks of glass) in front of an object.
But as a workaround, you can use two denoiser passes and blend them together - one with less strength and mask the glass by the refraction filter, here's an example:


Comp-wise it would look like this in nuke, but in other comping applictions it would be the same, only I've used the denoiser directly in nuke, but you can use the maya or standalone denoiser to produce the two passes: