I've been working on a voxel engine for a couple months, I understand how you can use 2d noise to make a heightmap, and 3d noise as a density value to chose what voxels should or shouldn't be solid, but that only gives you what I refer to as sponge terrain
How on earth do you get mountains and overhangs from that? It's confused me for some time now I thought of compositing them but that just leads to hills with a bunch of holes in them
I've read many related questions about this topic that I cannot link until I have more rep, I've even read the article on notches blog, and the article on moving blocks but they don't really go any more into how to generate these features than "You need to use 3d noise"
Any help or examples would be appreciated.
I was going about my solution all wrong, I was taking a 2d heightmap and cutting out noise of a certain threshold from a 3d noise, this did not work because the two noises were not related, Using a fractal noise and a noise gradient allowed me to solidify noise near the bottom as seen in this cross-section link, this article was very helpful in helping me realize this: http://accidentalnoise.sourceforge.net/minecraftworlds.html
