In UE5.7, objects using subsurface scattering or two-sided foliage materials display a red color in reflections such as glass, indicating abnormal reflection. What could be the cause, and how can this be troubleshooted and resolved?
I am having the exact same issue. Did you find the solution or maybe just a reason why this is happening?
Hello there!
Indeed, that red color shows an issue on how reflection is being handled, most likely due a conflict with the material in use, and how Lumen/Ray Tracing are hitting the lights.
Checking around the community, one solution is to change how Lumen rays interact with the mesh surface. Open your Post Process Volume, check on Global Illumination, and set “Ray Lighting Mode” to “Hit Lighting for Reflections”. This change will force UE to re-evaluate the material when light hits:
In addiion to this change, please make sure that Ray Tracing is enabled and supported in the foliage meshes in use, as well as in your project itself. For the meshes, simply open them in Content Browser, go to Details, and under “Ray Tracing”, check “Support Ray Tracing”:
For the project, go to Project Settings > Rendering, and enable the checks below:
Hope this helps, and good luck!
Hello, thank you very much for your prompt reply.
I am experiencing exactly the same problem.I tested the method you suggested, but when using ray lighting modes in Post Process, both HitLight and Hit Lighting for Reflections cause red artifacts in reflections. There also appears to be abnormal emissive glow across the scene.Only Surface Cache calculation works properly.
However, this method removes diffuse lighting entirely, making shadow areas highly unphysical and unrealistic.
THNKS,I WILL TRY.
THANKS!! I WILL TRY
This works, thanks !