In 2.79 when experimental feature set is activated, there are some new passes available to the compositor if Denoising is enabled.

The new passes that are there after rendering the denoising pass are as follows:

  • Denoising Normal
  • Denoising Normal Variance
  • Denoising Albedo
  • Denoising Albedo Variance
  • Denoising Depth
  • Denoising Depth Variance
  • Denoising Shadow A
  • Denoising Shadow B
  • Denoising Image
  • Denoising Image Variance

Here are a few example images of some of the passes with a simple scene:

Denoising Image: enter image description here

Denoising Image Variance: enter image description here Denoising Normal Variance: enter image description here

Denoising Shadow A: enter image description here Denoising Shadow B: enter image description here

The only information I have really been able to find regarding these extra passes is located here.

Quoting Lukas Stockner:

...added an option to store the denoising feature passes in the render result (only visible when experimental features are enabled).

This makes it a lot easier to debug problems and check why some scenes don't denoise well, and might be useful for animation denoising in the future (since that requires multiple frames at once, it has to be separate anyways).

Even still, I'm not sure how these passes help with debugging issues, or present any other use until implementation is completed.

The question: How are these passes to be used in current 2.79?

If they are simply for debugging issues, as mentioned by Lukas, or if there is another practical use for them, what would be a typical use case where it would be necessary to store them?

Here is the file used in the images above if anyone is interested:


There are no practical uses at the moment. It has been suggested that they will be used in compositor denoise setups, perhaps for denoising individual passes (as currently only the combined render is denoised.) However, whatever setup they are intended for has not been developed yet. It will probably happen when the denoiser is finished. So perhaps for 2.8, or perhaps not until later.

This info came from the blenderartist post. I asked about it here. I do not know if it discussed in more detail elsewhere in the thread, as the thread is huge!


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    $\begingroup$ I would say it provides the same benefit as all the other passes. There have been several tutorials on re-creating the final render by mixing all of the passes, the denoising passes expand on that to allow you to also combine them in any way you choose. So you could blur it before mixing or increase the mix amount, or not denoise the shadows... $\endgroup$ – sambler Jul 20 '17 at 5:27
  • $\begingroup$ @sambler Perhaps you could add an answer with a short overview of how to mix them back together? That would sort of invalidate "There are not practical uses at the moment.". $\endgroup$ – Leander May 14 '20 at 8:23
  • $\begingroup$ @Leander there is a difference between practical and possible. CGCookie has a tutorial on creating nodes that combine the base passes to match the final render. Today we have the Denoise Node which makes a simple case for using these. $\endgroup$ – sambler May 31 '20 at 5:07

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