LUMEN REFLECTION PROBLEM ON SINGLE GEOMETRY

International
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1

Hi everyone,
I have a problem!
I have taken an Alias model (surface) to VRED PRO. Prepared the entire model (high tesselation with correct normals and UVs) and exported as FBX. Then imported into Blender to create a rigg and then exported again in FBX.
I have imported the FBX model into Unreal 5.1.1 as a Skeletal Mesh.
However I have very low quality lumen reflections only on this particular model (specially in glass areas). The rest of static meshes and environment have crisp reflections as I am with Lumen with Hardware Raytracing enabled and 4096 resolution of reflection capture.
This makes me think the problem is on the import of model or model file itself as everything else works perfectly…

Anyone have any idea of what it could be?
Thank you all

(Running on Xeon Gold, RTX 4090 and 128gb RAM)

2

The problem is unlikely to be derived from the model, given how you’ve described the situation.

Lumen by default uses a low-resolution radiance probe system to provide GI to transparent surfaces-it’s expected for them to look bad unless ‘high-quality translucent reflections’ is tagged in the post-process volume, which runs the full lumen reflections pipeline twice for transparent geometry.

Furthermore, you’ll want to make sure ‘use hit lighting for reflections’ is enabled. The current lumen implementation cannot handle skeletal meshes without this setting, outside of screen-space. I hope this helps!

3

Reflection captures are also a system designed to be integrated with static lighting-lumen reflections are a separate pipeline entirely and the two are not expected to interplay.