Light build black shapes problem

Hello all !
I post here because I don’t have any new idea for fixing my problems.
I created a scene in unreal and, when the light build comes, I discover a lot of things but with the help of great people on the internet I fixed a lot of problems but I still get some really strange things :confused:
Screen taked after a “High” light build.
First, on couple walls in a room I get this big black things : Imgur: The magic of the Internet
Light only screen version : Imgur: The magic of the Internet

Second, I have an orange light, I touch the parameters etc but I still get some small light of her in other room like this : Imgur: The magic of the Internet
The light passtrought but very small, and the area of the light is not in this room.

Next, in the same room of the orange problem, my wall have an opacity maps but the light don’t passtrought the little holes like this here : Imgur: The magic of the Internet (the blue walls, that don’t get shadow by the way).

And the final things but I think it’s a uv things, the black walls here : Imgur: The magic of the Internet

So, problem list finished.
I want to add, all the walls have a 512 lightmap resolution.
I have Lightmass Importance Volume (all the object are in the area).

My world settings : Imgur: The magic of the Internet

I hope you can help me on this, I can’t found any other idea :frowning:
If you need any other informations, ask me.


Any idea about this please ? :frowning:

You need to make flat surfaces like walls out of single objects rather than constructing them from multiple objects–it’s bad for performance and it creates lighting issues like you see there.

Yeah but it seem like it’s a modular building here no ?

Ok but do you have a solution ?
Because it’s modular assets and I have a dead line so I will not go back to max and create a big walls, this will change my UV so textures etc etc … this is just how lossing time I guess :confused:

I fix the big rounded black things with moving objects but I think you speak about the big walls in the main room right ?
Can I fix this with touching the uv of the lightmap ?

No, the issue is that the walls are separate, which means that the lighting will get processed on them individually and there will be lighting variations between them. Making a simple surface out of multiple objects is bad for performance, that’s not how modular workflow should be done.