vray denoiser extra channels

[lukepenry]

When rendering the vray denoiser as EXR sequences, it includes all the extra channels i don't want, noise level etc , increasing the file size a lot. is there a way to just include the denoise result?

all i want is the original RBG the denoise effect and the a cryptomatte. is this possible?

[^Lele^]

Not currently, no.
It's done this way so one can make use of the more advanced multi-frame denoising, available only as a post-render method (using vdenoise.exe in the \bin folder).
It should be trivial for you to remove the extra REs as a nuke/fusion job (where i assume you'll make use of the cryptomatte).

There have been requests for a lean save of the denoiser channels (i.e. denoised result only) in the past, but those rapidly became a set of contrasting requests ("but please don't remove this as it's useful."), so nothing came of it.
The reasoning is that if one writes multilayer EXRs, after all, size on disk has little bearing on read speed (they only read what they need.), and disk space is plenty, and plenty cheap, today.

[lukepenry]

I’m actually using the cryptomatte in After Effects, I don’t have nuke!

The reason it would help me is that I am using cloud render farms and the extra channels makes each frame of this 1225 frame animation over 2gb as it’s a 4k animation. This would mean over 2tb worth of downloading and from what I can tell it does make a difference in After Effects on the read speed. Could be wrong though

[^Lele^]

You could enable multi-file save and delete the multipart EXR output, if that's a bother.
That way, you'll get both the original file and the denoised one.

If AE is having issues with multipart files, it's for AE to solve.
Here's an excerpt from the openEXR format specs:

• Multipart: ability to encode separate, but related, images in one file. This allows for access to individual parts without the need to read other parts in the file.

[lukepenry]

cheers! Is that the same as enabling seperate render channels? Because I have never gotten a cryptomatte to export correctly that way, it always seems to split it into 4 channels which don't have any data in them.

[^Lele^]

Eh, you're right, you'll need two passes.
The beauty pass, where the output is essentially the original and denoised RGB, without cryptomattes, and the data pass, where you may turn off lights and not render to a noise threshold (say, a 4/6/8 fixed AA sampling) where you output the multipart file with the cryptomatte in them (without denoising).
The data pass, done right, will go super quick.

You'll then have to remarry the cryptomatte and beauty in AE, but that should be doable.

We have an open request to be able to store the cryptomatte manifest in a sidecar file so that it can work with multiple files (thanks Peter for the tip!), we're bumping it with this thread, thanks for the feedback!

[lukepenry]

okay thanks, i'll look into this