If you are using the standard terrain engine and still want smooth and dense textures, then you can apply tri-planar mapping. It is especially useful when you are generating the terrain procedurally because you cannot use 3Ds Max or Blender to unwrap the textures and adjust UV mapping. The tutorial below explains how the tri-planar technique works:
→ How-to improve Unity terrain texturing tutorial – Raving Bots
I have submitted my version of the shader to the Asset Store. It is very easy to use, efficient, and compatible with the newest Unity version:
→ Terrain UV-Free Triplanar Texturing | VFX Shaders | Unity Asset Store
