I would like to know how I can do to create a dynamic landscape material that shows cliffs in the most inclined parts. Thanks 
Do you mean create a material that procedurally paints the terrain based on incline? Like this: https://www.youtube.com/watch?v=Kh8F3uUdiRA
I generally link to these because… I wrote them. And I think they’re not awful.
https://joy-machine.com/devlog/2015/10/8/generating-detailed-procedural-terrain-datasets (this is maybe not up your alley)
https://joy-machine.com/devlog/2015/9/25/unreal-engine-4-procedural-landscape-materials (this should be what you want)