Procedural mapping style experiments

[gilgamec]

One nice feature of the original map is the shading implying slope. This was the hardest thing to get right (and even so, I can't get the same slopes shown in the original). It's simple in theory: we can calculate the slope from the height field, take the dot product with a "light" vector, and shade (with blend type "Darken"):

Alas! The slopes in the mountains (in the east) are so high that there are very few slopes anywhere else. In order to show the slopes elsewhere, I change the shading to depend on the square root of the slope; this means that much smaller slopes will still be dark-ish:

The spatial scale is still too small, though. A Gaussian blur will take care of that:

So close, but too dark! I drop the opacity to 0.75 and cut back the darkest colour shown to be about 60% grey to get:

which is very nice (but, like I said, doesn't remotely match the shading on the original). The underlying grid is a little too visible, but I'll leave that for another day (as it's not too bad at this scale).

We add back in the vector elements to get a pretty good recreation of the original map: