Unfortunately, in addition to the already identified emissive material issue in GPULM, there is also a severe shadowing issue present in UE5.3.
@Arkiras has been able to reproduce this issue as well.
Example of the issue. (5.3)
Exact same scene and settings in 5.1.1
I was able to make some progress on this issue by disabling “support stationary Skylight” in the shader permutation reduction section of the project settings.
However, not that I’m not actually using stationary skylights.
This did allow me to bake lighting in certain sublevels, however, others remained broken.
This scene has some shadowing, but light is appearing from underneath the elevator machinery, which is a flat shelf. There also are light blockers that should prevent any light from coming up.
Doing some additional testing in this area, at some point somehow the engine just reverted to the completely broken state, and I have not been able to get back to where it was partially working.
