Denoising an EXR sequence.

[ripe]

Saw some stuff in an earlier thread - but no definitive answer.

I'm using 3.5 and rendering an animation to EXR files using Light Cache / Brute Force GI.

Getting nice quality and speed using denoiser but...

When I enable all channels and use denoiser on render elements as opposed to RGB - I get the best results and my textures stay nice rather then getting softened by the denoiser - but my EXR files are MASSIVE due to all the extra render elements getting saved. Is there not a simple way to denoise using the render elements (save the denoised RGB result as a channel) - but NOT save all the channels required into my EXR as I only want the channels I have specified?

[pg1]

Am struggling with this too.
If I generate a multi-layered exr. the file is huge.
If I turn off the vfb and use max render elements dialogue I a vray denoise element that has nothing in it.
If I generate separate render elements from the vfb I get the correct result which is fine for a still image but as all the elements are in one folder it becomes annoying with lots of frames and lots of elements.

[Svetlozar Draganov]

It's the way the denoiser works for now but obviously it needs some modifications.
The best way to get what you are looking for is as ripe suggested to render to a Separate Render Channels, this will remove the denoiser elements but other elements will be saved as a separate files.
Maybe we have to export denoiser elements only when the mode is set to Generate Render Elements Only, do you think this would be a good idea?

[ripe]

Hi Svetlozar.

Thanks for the reply.

Yes - ideally we need to have an option to NOT save all the required channels into the EXR - I only want the channels I choose to be in my files, not all the ones that Denoiser uses to work it's magic - I appreciate they are needed to calculate the denoise - but they should not be saved into the EXR unless the user chooses to do so, the default should be that they are not saved IMO and the only additional channel saved is the denoise result. It's making my animation files HUGE - over 100meg per frame as opposed to around 20meg - so it's slowing my workflow somewhat as After effects also has more work to do with opening / processing the files

[Svetlozar Draganov]

Animations should not be denoised during the rendering, they should be denoised via Standalone Denoiser tool once the animation is completed, this of course will require Denoiser render elements to be available otherwise Denoiser won't work. There should be an option to enable/disable Denoiser elements, it's default state is pretty subjective one might want it disabled in order to save some space and work faster in compositing apps another might want to keep the files in order to have the possibility to denoise the image again if needed.

[hardrock_ram]

Hi Svetlozar.

Thanks for the reply.

Yes - ideally we need to have an option to NOT save all the required channels into the EXR - I only want the channels I choose to be in my files, not all the ones that Denoiser uses to work it's magic - I appreciate they are needed to calculate the denoise - but they should not be saved into the EXR unless the user chooses to do so, the default should be that they are not saved IMO and the only additional channel saved is the denoise result. It's making my animation files HUGE - over 100meg per frame as opposed to around 20meg - so it's slowing my workflow somewhat as After effects also has more work to do with opening / processing the files

In my Nuke workflow I usually rerender the EXRs as a first step. I remove channels I don`t need. That way I get a scanline exr that is much lighter to work with.

[pg1]

Feel like Im missing something obvious here.
If I cannot use the output in the vray frame buffer how do I denoise an image?

I get a vraydenoise element but its empty and my rgba pass is not denoised.

[pg1]

We used to re-render exr sequences to get them as scanline but since they added the option to output exr as scanline in the exr dialogue box a few years ago we stopped.
Would rather have a way to output without the extra elements and also a way to get the vray denoiser to work without the vray frame buffer.
At the moment it seems to do a lot of things that are not expected.

[vlado]

If you want to denoise outside of V-Ray, you will have to use the V-Ray frame buffer with the "raw image output" option and .vrimg or OpenEXR file as output.

Best regards,
Vlado

[Leeds3D]

associated issue: if the better way is to de-noise an animation outside the render for an animation (rather than individually for each frame). are there any good ways to keep the vrimg/exr small? i'm finding my vrimg files for a 2000x1000 image is above 400mb each frame (this is including a number of the elements for compositing. Its killer if i'm downloading a 5000 frame animation from a cloud render provider at 400mb a go!

[vlado]

are there any good ways to keep the vrimg/exr small?

You can output 16-bit EXR files, if you are not doing this already. Using DWAA compression would have been perfect (it can reduce file sizes 2-3 times), but we need to change some things in the EXR writer. Hopefully for the 3.6 update.

Best regards,
Vlado