@grinseengel...
it isnt that complicated... Just import your Mesh into Blender, add an "edge split" Modifier to your Mesh, apply it and export the Model... Done...

Image where to find this option:


regards Sebastian


Tutorials:
[Blender]Terrain creation ENG/GER
[Blender]Low Poly Tree Modeling
[GIMP]Create a Texture for Terrains
CLICK HERE