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
If you need any other informations, ask me.


Did you take a look at the lightmap UV’s of those meshes?

It’s weird that it looks pretty good in the lighting only. And the shadows in the first picture don’t match those of the lighting only. Maybe you need to change the wall material.

btw. I don’t think you need to set the Indirect and Sky Bounces that high. You can easily half those values. Especially if you want to find the light error first.