Hi guys, I am new to unreal engine 4, have been using it for about a week, liking it a lot, I have figured out most of my issues with it. With building a open world-ish game, a game made of several blocks of area, about comparable to 5 city blocks. I use blender and photoshop for modeling and texturing, I have followed the tutorials for importing from blender, and everything is fine, but with a large mesh, such as a road mesh, if import it with correct tilling uvs, and a second set of uvs for lightmaps, the lightmap uv is much to small for a good res shadow maps, so I was wondering if it is better to build basic level geometry with the bsb meshes in unreal. I have not looked at them very much, but they seem like it might work. As a noob to unreal, what would you guys recommend?
As a search on the forums will undoubtedly lead you too … BSP should not be used for a final game and should ideally only be used for prototypes and quick tests. There are numerous threads with regards to this, just do a search … you’ll find them. 8-}
Here is one post:
https://forums.unrealengine/showthread.php?54641-Questions-about-making-Static-Meshes-for-UE4-Modularity-Light-maps-BSP-etc&p=194463&viewfull=1#post194463
You can use a BSP, but convert them to a mesh for the final game 
If you have a large mesh that can’t get a high enough detail in the lightmap, then you have to split it up into pieces.