Terrain Builder is out !
Find quick guide here : Quick "Terrain Builder" tutorial (Edit: Link removed) And look at visitor 4 Manual : Visitor 4 Manual




Before anything else, you should know that making a terrain in ArmA 3 is quite similar to ArmA 2 in many aspects, so check this amazing post :
Resourcelink collection: How to make a map, step-by-step


TOOLS



L3DT




GETTING STARTED WITH VISITOR

Setting up your P: drive :



Guides :



Tips & Tricks :



ArmA 3 new features

New road system:



Loading Text:


3D Editor:



Satellite normals:




Textures :




Other Ressources :