When objects are placed behind or beneath a masked landscape and r.Lumen.HardwareRayTracing.SurfaceCacheAlphaMasking is enabled, the direct light evaluation is incorrect.
There are two workarounds, but one of them only works in UE 5.6 and up:
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-347428 in the post.
| 0 |
| Component | UE - Graphics Features - Lumen |
|---|---|
| Affects Versions | 5.5 |
| Target Fix | 5.8 |
| Created | Oct 5, 2025 |
|---|---|
| Updated | Oct 10, 2025 |