Here are some screen-grabs right out of UnrealEngine showing a demo-piece I recently made.
I was using "Autolandscape Material" (thanks&shouts to Unreal Sensei) to distribute some
nice Quixel materials through different masks, I got from Gaea (terrain done entirely in Gaea)
Some extra sculpted rock formations and avalanches are blended into the terrain using RVT blend technique.
-enjoy!
KS