- In UE 5.5, add this line below CalculatePointShadowing is called in TextureMapping.cpp:
UE_LOG(LogLightmass, Log, TEXT("Shadow Sample %f"), ShadowSample.Visibility);
- Build UE5 Editor and UnrealLightmass
- Create a game project
- Add a DefaultLightmass.ini file in the Config folder and add the lines :
[DevOptions.StaticShadows]
; Using area shadows by default instead of filtering in texture space
bUseZeroAreaLightmapSpaceFilteredLights=True
- Open the project and in the project setting check allow static lighting
- Add a Stationary Spotlight actor and check "Cast Shadows", "Cast Static Shadows", "Cast Dynamic Shadows" and "Use Area Shadows for Stationary Light precomputed shadowmaps"
- Add two plane actors. Place one plane above the other plane so that it creates a shadow in the second plane
- Build Lightmass data with Build Lighting Only
- Open swarm agent and check the log. (Increase the MaximumJobApplicationLogLines to 10K to contain the entire log)
- Observe the value of ShadowSample.Visibility
- Perform the same steps for UE 5.6 and observe the value of ShadowSample.Visibility. The UE5.6 and UE5.5 results don't match.
- Disabling Embree by adding the following lines to DefaultLightmass.ini will make the result match between UE5.5 and 5.6:
[DevOptions.StaticLighting]
bUseEmbree=false