Here’s what i once posted in another thread:
https://forums.unrealengine.com/showthread.php?44234-Cinema-4D-Workflow&p=239465&viewfull=1#post239465
Level of Detail models can be exported as a own fbx and added as LoD inside of UE4.
In regards to materials, only the basic materials itself are exported, Textures have to be imported and reassigned to the materials manually.
You can have multiple materials on a mesh by using polygon selections on them.
If you need to have certain effects like procedural generated textures (e.g. noise), AO or whatever on the model, you need to bake out these textures using the bake texture Tag.