Applying Material to Procedural Mesh

I followed the wiki on creating a procedural mesh - A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums - but when I apply a material to the mesh, either the either mesh is just a color (just green instead of grass) or each quad has a dark and a light triangle of just that color.

Do I have to do something with the UVs? I’m generating terrain based on simplex noise.

Here are some screenshots showing what I am getting:

This is a placeholder material I made:


This is the terrain with the placeholder material applied:


This is a grass material I got off the marketplace:


And this is it in use, showing the weird dark triangle and light triangle thing:

Same problem here. Have you found a solution?

There’s this