Just a demo how 3d terrain generation can works. When you start the project you have to wait 2-3 seconds until the terrain is ready bright areas=mountains dark areas=valleys you can change the slider for different high mountains.
See inside the code, its very simple for example If you want to code 3d minecraft you can use this. I created this project only because anyone those name i dont will say dont know how to make 3d terrain generation for his 3d minecraft.