Hey guys,
So I created a room in my scene and used super simple lighting. There are a few point lights on the walls and a spotlight on the ceiling. I then duplicated the entire room because I need an exact copy of it. For some reason, the lighting in the second room is slightly darker. That may not sound important… but it’s a serious issue. Does anyone know why that happened?
Hi, could you send a picture of the two rooms? That would help identifying the issue.
You could be running into a stationary light issue if the rooms are close together, to many stationary lights in the same area will cause issues due to overlap
Other possible things i can think of are if they are not built ? if this is all real time then as Polysiens said can you post some images ?
Here are some pictures as requested. The GIF shows me teleporting from one room to the other. If the lighting were the same, you wouldn’t notice, but look at the walls. It gets darker. The final picture just shows how close the rooms are together. The yellow box is a lighting importance volume. The lighting is baked (which I don’t know much about but I’m pretty sure I did it right) and the lights are static. The settings for the lights are identical because I duplicated them.
Once ago I noticed lighting could change after duplicating a level (which has no sense, of course). What happens if both levels are “copies” of the “original” one? Instead of using one copy + the original, using just two copies.
Unfortunately they are still different. Great idea though
What are your lightmass settings?
Also it looks like your post process volume doesn’t completely cover the second room, is it unbound?
Yes, it’s unbound.
I don’t know much about lighting, so I apologize if this isn’t actually answering your question, but I did not alter any of the lightmass importance volume settings. I only put it there because UE5 through up an error without it. So, it does whatever it’s supposed to do by default.
I suspect your issue is caused by the fact that CPU lightmass processes different meshes on different threads, which has the issue of creating undesired lighting variation between meshes. Normally this represents itself as seams between modular pieces.
It may be worth trying GPU lightmass to confirm the problem, as it does not suffer from this issue. If it does indeed turn out to be the CPU lightmass thread problem, you may be able to solve it in a few ways:
Reduce the indirect lighting smoothness and use higher quality lightmass settings. I’d suggest trying these, but I warn you they will take much longer to build lighting for, especially if your lightmap resolution is excessive:
Or… merge them into a single mesh so that they all get processed on the same thread, the purest way to do this would be to merge all of the meshes in both rooms into a singular mesh. However it might be enough to just merge the corresponding meshes with eachother (ie: back wall for both meshes will be merged together, and so on for all the meshes)
