Denoiser and Render Mask

[baumgore]

If using render mask with Denoiser, the denoiser takes the same amount of time to process regardless of the actual rendered screen pixels.
This could lead to longer denoise times as the actual rendertimes.
Some optimizing would be great, i.e. the "noiselevel" layer is black on empty pixels --> telling the denoiser where no work is needed.

[Svetlozar Draganov]

Thanks for the feedback.
The initial release of the denoiser is indeed not very optimized since our focus was to fix the major bugs with it.
Future versions of that feature will have some optimizations.