What on earth is happening here? Black artefacts and flickering in Lumen reflections.

Development Rendering
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1

Hey Community,

Anyone able to jump in and let me know what’s happening here with my Lumen Reflections? Everything default in engine settings - Unreal 5.5.4.Mac with SM6 enabled.

2

Hello there @Damian_Grady!

That is a very strange occurrence with just default settings. Checking around the community, there are ways to deal with flickering, let’s try to implement some of them:

  • The first step would be to ensure your OS and video drivers are in the latest version available

  • Next, test disabling Nanite for your reflective meshes

  • Disable high quality reflections and screen traces from console command. These features are usual suspects for other flickering cases:

r.Lumen.Reflections.HierarchicalScreenTraces 0
r.Lumen.Reflections.HighQuality 0
r.Lumen.ScreenProbeGather.ScreenTraces 0
r.Lumen.Reflections.ScreenTraces 0

  • Disable hardware ray tracing as well:

image
image690×385 31.6 KB

  • Finally, test by adjusting the current value for rendering the reflection resolution. Go to Project Settings > Engine > Rendering, and look for the Reflections option. From there, increase the resolution value to improve reflection quality:

23-capt-refl-set-reflection-capture-resolution
23-capt-refl-set-reflection-capture-resolution840×560 40.5 KB

There are further methods to improve Lumen reflections, I suggest following this guide. It helped me a lot on my own projects.

1 Like
3

Hey @brs-sebascova
Thanks so much for taking the time to reply with guidance and a few options for me to try. It’s very much appreciated. I’ll report back asap.