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:
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: