In the recent Fortnite focused tech blog something stuck out to me:
“Some problems were easier to solve. Lumen uses screen traces to add detail where software ray tracing is lacking, but grass is so detailed that these screen traces were introducing significant aliasing. A simple workaround to skip screen trace hits on foliage was enough to solve the artifacts.”
This seems to suggest it is indeed possible to skip scene traces for only certain elements.
Perhaps @Daniel_Wright could enlighten us on if this is something we can easily apply elsewhere when screen traces are unwanted?