Intel Denoiser + alpha awareness!

[^Lele^]

As mentioned, the V-Ray denoiser does a better job of it, but if you're after physically accurate, you should avoid denoising entirely.
Attached, a custom mode with 1.0 strength and 50 px for kernel size.
We only implement OIDN, and we can't make substantial changes to the tech by ourselves.

To answer your doubt, however, yes, denoising always had issues, and will continue to sport limitations for the foreseeable future.
There is no guarantee, explicit or not, that a denoising job will work just fine for any given scenario.
Emissive surfaces behind glass are one such corner case that never was, and currently isn't, well handled (whereas non-emissive behind glass works fine, with the caveat of affecting all channels for the glass.).

As for LWF, hit me via email, and i'll try and help.

[HowardDay]

Heh, true enough. I'm over here wanting accurate but fast, obviously I shouldn't realistically expect that. Thanks for walking through it with me.

[^Lele^]

Oh, we'll use this specific scenario to investigate ways around it.
Wether that'll be in OIDN, or our denoiser, or both, is not yet clear.
We have ideas, but no ETA.

[piotrus3333]

I've just tried ODIN on Refraction pass separately and it does much better job than on RGB color. So maybe use Source: Composite in VFB and comp it back from separately denoised elements?

[HowardDay]

Piotrus: ..I have no idea how to do that. I don't actually use the VFB for much at this point, I'd love a quick rundown on what you're doing?
Thanks!

[piotrus3333]

file via pm.
basically this:

[piotrus3333]

there is VRayBackToBeauty element that will do it for you automatically but for some reason it does not work as expected in this case so you need to add all needed elements one by one. you probably wont need all of those, depends on the scene.

[^Lele^]

Very clever, it never occurred to me that it could be done with the VFB.

[HowardDay]

I second that, genius. I'm already seeing better results. Thank you!

[piotrus3333]

I was under impression that this is the intended workflow for old and no longer available mode of denoiser: denoise render elements separately.

edit: just the bug with Denoise option in VRayBackToBeauty not working is making things less convinient. but than I'm not on the latest version so it might be ok.

also it would be nice to be able to have a version of an element denoised and original. for me it the later rendered black.

[HowardDay]

It's definitely still broken in the nightly from 10/30.

[HowardDay]

Okay, so now I apparently don't understand how to get VRay to *save* out the denoised result. This is what I see in the VFB as it renders:

And this is what's saved to disk:

Obviously I'd hope they'd match.
I do get a logged warning:

But I'm not saving the REs but just the final image result, right?
Here's my setup:

I hope this is an easy fix, cause VRay's rendering it right! I just want to save the result.
Thanks!

[piotrus3333]

you need to save through render settings > vray > frame buffer not render settings > common.

[HowardDay]

So what are the best settings there to get a single set of exported EXRs, like I was getting from the Common panel? I'm currently using separate render channels, as that's the only way to enable any of these settings:

But that exports a bunch of stuff I *don't* want.
Tons of garbage.

I want *just* the final effect result.

Thanks!

[piotrus3333]

VRay raw image file will give you an option to save as one multilayer exr.