Seeing weird lines on FBX model in Unity after applying materials

[cubus331122]

HI ,
I’m pretty new to Blender and creating my own models. I made a pistol model, and it looks fine in Blender.

I tried exporting it as an FBX, packing and unpacking the textures (I read that Blender materials aren’t really compatible with Unity), and I also tried using Smart UV Project before exporting—but nothing seems to work when it comes to transferring materials from Blender.

So, I ended up importing the model into Unity without materials, added some there, and when I applied them, I noticed weird lines showing up in some places:

What did I do wrong, and how can I fix this?

PS
I’ve read that post:

Weird lines in object(exported blender texture to unity)

Hello Everyone, So here I have pistol I made in blender and UV unwrapped correctly as I checked multiple times. For some reason the grip is coming out with these weird lines. These 3 photos shows the texture and it on a material thats on the grip and the correct UV unwrap [help em 3.PNG] [helpme2.PNG] [helpme 1.PNG] , if anyone has any advice?

but I think my issue is a bit different.

[kdgalla]

Looks like the UVs are bad. When you press “Smart UV project” in Blender, maybe you didn’t have all of the relevant faces selected?

Just clicking “Smart UV Project” may not be enough. You’ll need to actually edit the UVs so that the texture maps to the model how you want it to.