I am building a procedural terrain using UDynamicMeshComponent. Each ‘chunk’ that is calculated is joined using FDynamicMeshEditor->AppendMesh. Finally, once all calculation/merging is complete, FMeshNormals::QuickComputeVertexNormals is used to calculate the vertices for the final mesh.
Here is how the issue looks using the world normal visualization:
That is zoomed in on the border between two chunks (which have since been joined into one mesh). The normal difference results in a poor look on these edges, and seams.