Issues with the Official DLSS 4 Plugin in Unreal 5.5

Gaming and Visualization Technologies Engines Unreal
1

I’ve tested the official DLSS 4 plugin, and I have to say the results are disappointing.

Here are the key issues I’ve encountered:

  • Compilation Warnings: The plugin generates multiple warnings due to the use of deprecated functions or incorrect declarations.

  • Screen Space Emissive Issue: Just like the community-tweaked versions, the plugin incorrectly retrieves information from the screen space for translucent emissive materials with lumen enable. TSR, XeSS, and FSR do not exhibit this problem.

Expected result (TSR, TAA, XeSS, FSR) :

HighresScreenshot01210
HighresScreenshot012101920×1080 26.7 KB

Result with DLSS 4 in 5.5 incorrect :

HighresScreenshot01211
HighresScreenshot012111920×1080 34.9 KB

This “hack,” if it can even be called that, of using a translucent emissive material with an opacity of 1 is widely used to make Lumen ignore it, thereby preventing screen tracing and noise from appearing in the scene.

In the end, this “official” version is no better than the port I had made myself from the 5.4 plugin to 5.5. The difference is that it took months instead of just a few minutes on my end. All this waiting for nothing it’s on the same level and still not production-ready.

Here is the issue in video, with a comparison between DLSS On and Off with TSR :

Very disappointing.

1 Like
2

I investigated and found the cause of the issue. It occurs when Separate Translucency is unchecked.
In this case, it causes issues with DLSS and screen traces, whereas TSR and others work correctly.

Capture d'écran 2025-02-26 223229

Here is a test project that replicates the issue:

Re-enabling this option “fixes” the issue.
However, if you need to keep it unchecked for project-specific reasons, you’ll have to wait for a patch.

Update :

The issue can also occur with the new screen trace feature enabled.
Capture d'écran 2025-02-26 224715

Setting it back to “Scene Color” fixes the issue.

1 Like