Hello. I was inspired by procrasimnation's hijab lookbook and wanted to combine their hijab and lonelyboy's scarf into a morphed accessory. I remeshed their model to have smoother topology. And for uniformity, I made the diffuse a grey square.

It looked fine in tsrw, but the shadows look disjointed in game. There're weird bright areas and dark areas on different parts of the mesh. I tried applying a fabric pattern to give it some texture, but it still didn't look right. What can I do to fix this?

I've attached the accessory. Ignore the receding hairline.

The problem that arises from using a blank texture is that you can't generate a proper normal map from nothing, which is likely the main culprit here.
A blank normal just tells the lighting engine that part is flat, which obviously isn't appropriate for a mesh that isn't flat.

Additionally, there's a fair bit of UV overlap on the scarf which can impede the normal map from functioning correctly as well.

Side note, there's something very bizarre going on with the clothing category flags in that file - it has every flag, enabling it even for horses and plumbots? :P

I replaced the normal map with a flat one. I checked horseriding and other situations because I thought it would meant the acc could be used for those categories. I changed it so it's only available for everyday for now. The shading seems to be working, thank you!

Didn't we just go over how to make a normals map? An FYI, you can use a gray 32 x 32, to make a temporary normals map for testing, or even leave that in the package if you don't need normals detail. But perhaps you missed that when using the multiplier, you need another layer behind it, filled with solid color. Otherwise, you have to change other settings.

Another thing is that it looks like something happened to your UV, and some vertices didn't split. Because you use a solid gray in that area, just unwrap it, and it should work.

Yes that's right. I guess I was rushing through the process and forgot to fill in the background of that normal. I'll try unwrapping it again just in case, thank you!