i want to make a texture where grass, stone, etc textures are automatically applied to the landscape based on how steep the ground is. (ex: as you sculpt the landscape grass stays on the flatter terrain and stone appears on steeper areas automatically as you sculpt)
take a look at this thread
https://forums.unrealengine.com/showthread.php?89191-Auto-Terrain-Texturer-Version-2-Release
Does this tutorial get you what you want? Unreal Engine 4 Tutorial - Procedural Material Based On Slope - YouTube