Hi All,
I am having some trouble with Lumen in UE 5.3.2 that I’m hoping you can help with.
We have this scene which has a 15km long road with all the detail you can see in the image below as well as some extended terrain around the outside:
We are struggling to get all the objects to display in the Lumen view and have them contribute to the global illumination. This is all that was visible when I switch to the Lumen Scene views:
I thought this might be related to the size of the objects, because the road mesh for example is one mesh for the full 15km. When we split the mesh into smaller sections, the road starts to appear in the Lumen View:
We assumed this was a fix and started to split all of the large meshes, but this didn’t work as well for things like the road markings and the road barriers. To get the road barriers and the markings to appear in Lumen, we need to split the meshes into lots of smaller meshes which would mean we need hundreds of meshes to cover the full 15 km route. Is this the correct fix and only way to get those meshes to appear in Lumen? We have gone through all of the other settings for Lumen and tried to tweak the settings for more detailed meshes etc. But nothing seemed to make a difference other than one setting which was the Hardware Ray Tracing. If we turn that on in the project settings, we get a lot more detail and more meshes appear in the Lumen views:
However, turning Hardware Ray Tracing on in my scene reduced the FPS by 40-50%. This isn’t really viable for this project so I don’t think that’s a solution we can go with. If you can help or if there is any advice you can give us, we would really appreciate it.
Thanks,
Adam