Advanced customization of Open Image Denoiser [Solved] Tweet

[LewisO]

Edited:
Ricky provided an example setup herehttps://render.otoy.com/forum/viewtopic.php?f=102&t=83378
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I really love the Open Image Denoiser which offers much better quality in most cases.

To be clear I use only the Houdini plugin but I don't think it's possible to have it in Houdini before anything said below is doable in the standalone.

Is it possible to customize the layers fed to the Open Image Denoiser? It's not a usual thing to do BUT it can be so much more useful to have this in certain situations.

Right now it's hard-coded to use the albedo(which I believe to be something similar to the diffuse filter with refraction in mind), this is good for most cases.
But it's pretty much useless if the object itself has no diffuse, and only constructed with refraction/colorful transmission/subsurface scattering (with or without textures/procedural noises etc) In these cases, it would be awesome if one can control what to feed into the albedo channel of the open image denoiser so one can construct a more visually accurate representation of the raw colour albedo requested by the denoiser, instead of the black *albedo* without textures from other BxDFs etc in considerations
Even better if it's made of a customizable denoising render AOV group network (in which I can use my custom AOV outputs). If there is already such a thing it would be really appreciated to expose it to users.

[skientia]

Worth mentioning that the compositing + denoising can be setup in Standalone as well as any compositing software where none of the inputs are hard-coded to specific AOVs.

Edit: the Open Image Denoiser documentation does mention this particular case:

Using auxiliary feature images like albedo and normal helps preserving fine details and textures in the image thus can significantly improve denoising quality. These images should typically contain feature values for the first hit (i.e. the surface which is directly visible) per pixel. This works well for most surfaces but does not provide any benefits for reflections and objects visible through transparent surfaces (compared to just using the color as input). However, this issue can be usually fixed by storing feature values for a subsequent hit (i.e. the reflection and/or refraction) instead of the first hit. For example, it usually works well to follow perfect specular (delta) paths and store features for the first diffuse or glossy surface hit instead (e.g. for perfect specular dielectrics and mirrors). This can greatly improve the quality of reflections and transmission. We will describe this approach in more detail in the following subsections.

[LewisO]

Worth mentioning that the compositing + denoising can be setup in Standalone as well as any compositing software where none of the inputs are hard-coded to specific AOVs.

Edit: the Open Image Denoiser documentation does mention this particular case:

Using auxiliary feature images like albedo and normal helps preserving fine details and textures in the image thus can significantly improve denoising quality. These images should typically contain feature values for the first hit (i.e. the surface which is directly visible) per pixel. This works well for most surfaces but does not provide any benefits for reflections and objects visible through transparent surfaces (compared to just using the color as input). However, this issue can be usually fixed by storing feature values for a subsequent hit (i.e. the reflection and/or refraction) instead of the first hit. For example, it usually works well to follow perfect specular (delta) paths and store features for the first diffuse or glossy surface hit instead (e.g. for perfect specular dielectrics and mirrors). This can greatly improve the quality of reflections and transmission. We will describe this approach in more detail in the following subsections.

I have been doing this in the past two or three years using Houdini's own Open Image Denoiser in COP, but it's way better if you get it in IPR to see the results on the fly rather than another extra step of the independent process after the render is done.

[LewisO]

I don't know if that's the case in the standalone, if so it would be great news as all the work left to do is up to the plugin dev to expose it to users

[skientia]

I have been doing this in the past two or three years using Houdini's own Open Image Denoiser in COP, but it's way better if you get it in IPR to see the results on the fly rather than another extra step of the independent process after the render is done.

Undaniably.
For clarification sake, in case of misinterpretation, there was no subtext indicating to exclusively denoise in post, but rather that final frames can be denoised via any suitable AOVs given the fact the plug-in input limitation is strictly plug-in(s) related.

I don't know if that's the case in the standalone

The reply was to indicate that Standalone (and compositing software) do not have such limitation:

[LewisO]

I have been doing this in the past two or three years using Houdini's own Open Image Denoiser in COP, but it's way better if you get it in IPR to see the results on the fly rather than another extra step of the independent process after the render is done.

Undaniably.
For clarification sake, in case of misinterpretation, there was no subtext indicating to exclusively denoise in post, but rather that final frames can be denoised via any suitable AOVs given the fact the plug-in input limitation is strictly plug-in(s) related.

I don't know if that's the case in the standalone

The reply was to indicate that Standalone (and compositing software) do not have such limitation:

I don't see why it's technically impossible to use the aov compositing on the fly but only the completion frame. Still that's neither the answer nor a solution to my feature request here.

[skientia]

I don't see why it's technically impossible to use the aov compositing on the fly but only the completion frame. Still that's neither the answer nor a solution to my feature request here.

There was never a mention of impossibility nor meant to be an answer or solution, which solely comes from the development team.
The genuine intention was merely to provide options, given the limitations. It may not be relevant to you but can be to others.