Game coding

/frog/, I'm writing a 3D game and I need help with the logic.  I'm trying to model the ability to walk around anywhere on earth.  In order to do this (& keep it interesting), I need a map generator.  I have the temptation to model it after minecraft's block generator, but I don't want to have a blockly terrain.  It should be regular terrain, like Elder Scrolls or Halo.  Does anyone have an idea about how I would do this?

tl;dr: how do I make a normal map generator?

Adler Scrolls did not have autogenerated terrain.  It was modelled by hand by a team of chinese slaves in chains.

Also you have not specified your desired map format, or have given any sort of technical specs, which means that you have not written anything, or have any clue about programming.  Thus, fuck off.