@anonymous_user_972c05d8
I’m sure about a specific Unreal plugin, but I’ve personally used a Blender plugin that uses ArcGIS data to create 3D models of cities, landscapes, terrain, and roads.
Here’s the link to the page, there’s both a free and paid version:
My best advice would be to figure out a unique way to scale the models so that your flight sim still feels real, but uses less space to compute. And to mess around with the culling, a lot.
I hope this can help, it seems like a really cool project!
-Zen