To show what went into that map, below is the layers setup that I used in Photoshop. It's a moderately large stack of Wilbur outputs.
Layers.png
In this map, layers are simply stacked with varying transparency; I didn't do any multiplicative effects. The stacking of grayscale images results in a fairly washed-out image that I tried to bring back with the contrast and saturation adjustment layers. Not terribly successful, as the whole thing looks a bit muddy.
The top two layers are for the map border. A black-filled semi-transparent layer gets the dark frame and a stroked white border of that selection gets the white line.
A sea mask is used twice in this image, once as the basis for the coastline stroke (select and cut the sea color gives the land outlines, which get a stroke style) and again as a darkening agent for the sea areas.
The rivers layer is the basic output from Wilbur with the solid-color background cut away. I should probably have used a layer mask or blending mode, but select and cut is easier for the hard-edged river mask.
There are two ambient occlusion layers because a larger occlusion radius gives larger and darker valleys, while a smaller radius highlights more detail. The two together give a more delicate effect that either alone. Of course, they are pretty much over whelmed by everything else.
You may notice the unused "Contours" layer. My original plan had been to go with a grayscale base with color rivers and contours on top. It looked a little odd and so I opted for the color base layer and to leave out the contours (I moved the contours layer to the bottom to just get it out of the way).
The color layer should probably have been a straight color map without any lighting at all, but I had a 90 degree vertical light on it and it seemed like a lot of effort to go back and change it. In an ideal world, I would have used the height map as the input to a gradient map in Photoshop and gone from there. Or maybe used the V2 shader in Wilbur instead of the basic one.
