Shadow grain and jitter

Development Rendering
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1

I’ve seen many topics on this problem, unfortunately the solutions I’ve found don’t seem to work. No RT supported. The rest of the project settings are the same with this tutorial.

Screenshots of the problem:
Exterior sample:

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Interior sample:

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This is my general lighting components, however the problem seems unrelated to them because even if I disable them all nothing changes in the screenshot with the interior point light. Also at the moment “Force no precomputed lighting” is on (although if I understand how this works, I plan to turn it off, make all lights static and build lighting to improve performance).

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In my PPV lumen is set to these:
(Although it doesn’t probably matter because even if I hide the PPV the problem remains)
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Now a screenshot with Shadow Maps instead of Virtual Shadow Maps:
(The grain is still there, just less exacerbated and more “static”, so I suspect it’s not the real problem.

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Also this doesn’t appear on a few meshes/materials
(dragged a light into the scene and floor seems ok):

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Grain seems to appear when viewing the material:

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I have tried these to no effect:

  • r.Lumen.ScreenProbeGather.StochasticInterpolation 0’
  • Disabling contact shadow on the meshes (only removing shadows completely makes it go away)
    *Setting source size of the torch to 0. Changing to to movable/static/stationary.
2

Hi,did you fix it ?

3

Nope, have been trying stuff for hours :confused:

4

Are you using PDO in your materials that exhibit this issue?

PDO basically can’t be used on any shadowcasting mesh without artifacts. This looks like the typical result you get trying to use PDO with virtual shadow maps.

With regular shadowmaps you may be able to slightly mitigate this issue by increasing the shadowmap bias, but it won’t help much.

This is simply due to the way PDO works.

As an additional aside; It looks like you have no antialiasing enabled. Enabling TAA/TSR might help mask the artifact, but again… it isn’t going to help much.

Your best option is to just not use PDO on shadowcasting meshes.

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5

PDO was indeed the culprit in the master material graph! Many thanks mate!

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