The Sunny Side of the Mountain

The other day I was admiring the mountains in Kacey's amazing Ehren map:

I really like his shading approach.  (But go admire the whole map, it's well worth your time.)  One element of the shading is contour hatching with trailing lines behind the ridges.  That's not too different from the scribbled hatching I've been using, so I thought it would be a fun experiment to implement that sort of shading.

The basic approach is pretty straightforward -- rather than drawing back and forth as I do with scribbles, I just draw in one direction.  On top of that, I make each line trail off as it is drawn, so that it starts thick and gets thinner.  Finally, I have to do some tweaking on the lit side of the mountains, since the shadows there should be lighter there than on the other side of the mountain.

I think this looks pretty good.  Here's what it looks like on the map:

Here I have the shadows darkest right at the ridge lines.  That might seem backward; you might think the shadows should be darkest where they are farthest away from the ridge lines:

Orienting the shadows that way makes the mountains look more rounded.  I think I prefer the first version, but the program can easily generated it either way.  It's also easy to generate solid lines:

This gives a more two-dimensional / graphics arts sort of feel, but looks very flat on a map.

In Kacey's Ehren map, he also puts a gradient underneath the contour shading to add more depth.  SVG does linear gradients, so let's see how those look as mountain shading.  There's a lot of possible complexity here, but I'm going to start with a simple right to left gradient from 70% transparent to fully transparent:

And here it is combined with contour hatching:

And with reversed ("rounded") shading:

Here's what gradients + contours looks like on the map:

Overall, I like this a lot, and it's now the default shading for the mountains.