How not to get ugly landscape mesh faces?

this is what ue4 creates when you import a heightmap, a very much wrong topology.

It’s not “wrong topology” it’s 4 vertex per square meter…
If you want it to look better you need more than 4 vertex on each square meter.

Topology has nothing to do with it since it’s always the same. 1 vertex every meter, regardless of their Z position.

but if you change the topology in that picture youll get much better landscape