Here is an example of the latest World Machine setup I'm using for large area mapping with the output resolution of 30m/pixel.

Terrain is generated in three steps, base terrain, highlands and features. It also includes river and lakes, and something I call FILL LAKE. Fill lakes are just my term for filling any depression in the terrain with a level surface without altering the terrain under the surface, great for salt flats, mounting lakes and such that have no natural inflow or have eroded the landscape around.

The file is set up so you can easily (well relatively easily, we all know WM..lol) plug more of of each of the terrain generation routines.

Textures and forest are only rudimentary in this setup, I'm working on that part. It has support for multiple Biomes that handle general and forest texturing. The placement of forest are controlled using separate FOREST SPREAD controllers for multiple ways to place forest and you can create more as needed.

I will make a video explaining this setup in more detail soon, and there will be new versions of this as I add features. I'm giving you a chance to study it, play with it and see how I do things under the hood.

The goal with this setup is to be as modular as possible, so I can plug in or reuse parts of this in various other projects. The LAKES and RIVER functions are very powerful, in my humble opinion better than the ones built into World Machine.

To be fair WM's rivers are still in beta, and I'm sure Stephen will make WM's native river function much better than what I have managed to do in the not too distant future. But in the mean time this works fairly well.

I will make a special video explaining how it works.   

You can grab the file here: https://www.dropbox.com/s/27djc970mo2611o/2018_1-30m%20setup.tmd?dl=0