Upgrade to 5.1 Causes Glitched Rendering


After upgrading a small test project of mine to 5.1, the rendering has gone very bad. See image below:

I am trying to find the problem, but so far, no luck. I did get some error warnings:

But I have fixed those errors and restarted the project. I am also using an AMD 6800 xt with the latest drivers of :“Adrenalin 22.11.1 Optional” and on Wondows 10.

Any help would be great!

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Im having this exact same issue, anyone manage to find a solution?

I did enable SM6 and try a range of things from lighting, ray tracing changes and shading changes with no luck.

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Maybe is the same problem here. in my UE5.0.3 everything is perfect, but when updating to 5.1 and change it to shader model 6, every rect or directional light ends up in those strange white squared noise.

As you can see, spot light and point light, as well as path tracing(with all kinds of light), are working fine.

I´m using a ryzen5 2600, 40gbram and a RX6750xt. Windows 10. both directX and amd video drivers updated.

Hey everyone, “happy” to see I’m not alone.
Have same issue described right here

What I have investigated so far:

  • It’s about combo of Raytraced shadows + Virtual shadow maps/Shader Model 6 + UE5.1. On 5.0.3 everything works fine with SM5 and SM6

  • For some reason virtual shadow maps work fine with SM5 in 5.0.3, but refuse to work with SM5 in 5.1.

  • It’s not about light type as you mentioned, but about light radius. If you will take point light and increase it’s radius from 0 it will create same issue.

  • Looks like it’s related to AMD GPU, since we all have it (mine is RX6600, drivers 22.11.2)

  • TEMP FIX: If in UE5.1 you will turn off SM6, turn on SM5, turn off virtual shadow maps and turn on Raytraced shadows - issue will be gone. I wonder it will loose in quality with such settings? (how do I get rid of this noise in the shadows?):

At this point I’m wondering if there is any point in using 5.1? 5.0.3 should provide nearly same lightning quality options without this issues, right? I wish we could tag a UE developer here somehow, because it’s clearly AMD/UE bug.

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I remember reading on the forum that from 5.1 up only pure hardware ray-tracing will be supported for newer cards. 5.0.3 was the cutoff point where the 20 series and older amd cards would still be able to use it.

I think it has to due with the switch of architecture in the cards. (probably lovelace & rdna3 on-wards)

Interesting, still hope this is not related since cards mentioned above here fully support SM6, standard RT (don’t know if it’s “pure” or “fake”) and are 20/21/22 year of release, so it’s kinda stupid.

This also makes me wonder what RT settings in which UE (5.0 or 5.1) should I use to get maximum quality

I think they were axing pascal support not sure about the amd family.