Lighting problem

Hello, when I build my game, I encounter errors like this, and all of my errors write the same problem. How can I fix them?


Create a better lightmap for your meshes!! /or let Unreal do it for you!
Lightmaps should not overlap: every pixel needs their own information!

/google is your friend! :wink:

Thanks for your answer, I did some research on the internet but I could not access this information :slight_smile:

I managed to fix some of the errors, but some still give the same error. Although I have done the same thing in all of them, you can see that I added in the picture.

I can’t really see what part is what part but if Unreal says it’s overlapping then it is! :wink:
Did you lay the uvs or is it auto generated? …you can try Unreal to generate it for you…
Y…you can also upload the mesh if you’d like and I can check it…

UVs were created automatically. I set up automatic generation when importing in Unreal. But I am still facing such a problem. I get a lot of warnings this way, the same thing happens with the other things I upload.

That sounds a bit suspicious that the UVs are overlapping by exactly 50%. Above that there’s 100% overlapping UVs! How could it possibly be the case? Every line would have to be overlapping every line, unless the determinant of percent overlapping is based on a sliding scale or something.

It sounds more like a bug or an error of the engine’s UV check than the actual issue being overlapping UVs. How did you generate the UV lightmaps inside UE?

Could it be possible that your mesh has overlapping faces? Like duplicated polygons on top of each other… ?

How can I understand this, because I have no idea.

Can you upload the project with all the files used in the level?

How can I do this, where should I install it?

There’s several online services for free. One is DropBox, and also Google Drive. Try DropBox…

  1. Go to, and upload the entire project folder (when uploading, select the folder for the project…not any of the folders that contain the project folder).
  2. When it’s done uploading, get the link to it somewhere on the page. Copy and paste that link in the thread here, in a new reply.

Overlapping faces means in the 3D model, there’s a second face on top of another face so they’re in the same spot in the model. Or one face is partly in the same location as another face, like two sheets of paper, one on top of the other (or in the same exact space).

The size of my project is 20 GB, is it not possible to handle it all without loading? I get a lot of the same error, all of them have a different mismatch rate, don’t I have the opportunity to deal with them the easy way?

Because of my internet, I am doing this right now. I am sharing the link where I installed the fence instead. You can download it here. Don’t forget to activate automatic UV generation when transferring to Unreala.

20 GB!? That’s huge. I’ll download it though, and look at it, if you want. I don’t think getting a few meshes from it and having a look in my project or a new project would suffice. The problem is in the project you’ve made and modified.

Send me the link to the uploaded project, and I’ll download it. I have plenty of time, and 20 GB probably is 1 hour or 2 at the most to download.

Alright. Thanks. I’ll see if I’m able to yield a similar output / error.

Did you get the error? Did you find anything about his solution?

I’m testing it today. I downloaded the free meshes, and textures from the TurboSquid link. I’m thinking automatic UV generation might be the problem, although I’ll still activate it during import.

I tried to import the fbx meshes, but it didn’t import because there’s no smoothing group information that was applied in C4D. I’m not sure how you were able to import the meshes. Perhaps you could screenshot the Import settings used in Unreal Engine when you did it, even for only the fence mesh (by re-importing the fence mesh(es) from the same fbx file you provided the link for). Otherwise, I think I won’t be able to help.