Some new mountain tech. I've been really struggling with this step of development since it's so loosely defined but I'm still managing two steps forward for every step back.
The new mountains are part of my general solution for rendering the world. A very high resolution picture is made that just shows if a pixel is water, land, or river. Since every pixel is just one byte, this picture can be held in memory without issues.
Then new chunks are procedurally rendered as needed. For every pixel in the chunk, the distance from it to the nearest water is calculated. This gives a general mountain look. A lower res height map is then added to this so that rivers and lakes are not at sea level.
This height map can then be used by the shader to deform the mesh.