Denoise ray-traced shadows

Unity Engine
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1

Hello,

I am wondering is there any article or paper focusing on denoise ray-traced shadows? I googled a lot and just find some ambiguous general idea.

“The denoiser is aware of the information about the light source, such as its size, shape, and direction and how far away it is from the receiver, as well as hit distances for shadow rays. The denoiser uses this information to try to derive an optimal spatial filter footprint for each pixel. The footprint is anisotropic with varying directions per pixel.” — Ray TRACING GEMS PREVIEW PART V

Currently I am just using a Gaussian Based denoiser, But the result is not good in some cases.

High roughness, High Metallic, Fine:

1378×761 160 KB

Medium high roughness, HighMetallic, Noise:

1374×769 139 KB

Low roughness, High Metallic, Fine:
1383×764 111 KB

Medium high roughness, low Metallic, Fine:
1375×762 114 KB

High roughness, low metallic, overblurred highlight shadows(the shadow under the green light):
1376×769 106 KB

Any ideas to improve denoiser quality?

Thanks

2

Best would be to just ask x.com on twitter. He always answers ray tracing stuff pretty fast :smile:

3

Also denoiser state of the art are currently moving to machine learning (dnn)

4

Thanks, I think I’ve found what I need.
https://research.nvidia.com/publication/2017-07_Spatiotemporal-Variance-Guided-Filtering%3A