Weird lines across the land.

My map has these weird lines allover it.

The land is split up into squares but i grouped them alltogeather after the displacements were done.

Is it a lighting error maybe, how can i correct this?

You sew the displacements together?

Also try “Treat as one” (for the lighting issue)

I clicked sew but then it ruined the displacements.

Did you use subdivide at all on your displacements?

Destroy the side faces of the displacements, don’t make a whole brush a displacement.

Ah right, thank you.