Weird lines through static mesh

I have weird lines through my static meshes, they look like this:

How can I fix that?

Examine your mesh in your modeller.

I’m assuming it will be either the normals are wrong for the faces


The weird arrangement of the mesh - (might need to be tidied up to be cleaner, looks like the cylinder you put through the wall is radiating the faces away, i guess a quirk of subdividing.

So, how do I fix it?

The mesh was first a box BSP with a circle BSP which was subtractive and I made both into one static mesh.

In a 3D modelling package - like blender. For exact instructions, please see the docs of your preferred modeller.

I made the meshes in UE4, I don’t use blender for big walls.

Thats not the point. the conversion from BSP to Mesh changes it to a mesh, and now modifications can only be made in a 3d modelling package.

I don’t really know. But it seems like lightning problem… Maybe UV shading since it’s not a texture/material problem. Try checking UV shading from your modeller