I tried to export the entire level with FBX/OBJ, but the material/texture information is lost. Any ideas how to do this?
Take a look at this thread: https://forums.unrealengine.com/showthread.php?4907-Tool-UE4-T3D-Converter-for-bsp-brushes Otherwise you have to export and unwrap it -> then import it
Any way to maintain textures?
Bumping to find a way to maintain textures.
As Fighter suggested, when you’re using the FBX/OBJ export you’ll need to unwrap it then reimport. You may have some luck with the exporter that is suggested but this is not supported by Epic. I have found that it can cause issues when importing with it that result in “invisible” BSPs that are converted to Subtractive brushes even though they appear in the Top, Side, Front views and are listed as Additive.
With regards to “maintaining the textures” can you not apply the materials again? Do they not appear right on your mesh?
If it’s something wonky with the mesh and the textures that needs better explaining please include a screenshot as this will help to resolve the issue you’re having much more quickly!