So, in my last post I remarked that for procedurally generated landscapes to be interesting, they would need features. But what sort of features was I talking about? Population centres, in particular, tend to to be found close to certain kinds of... things. The first of these which always comes to my mind is the "defensible position." Something like, say, Edinburgh Castle.

A lot of the truly great cities in Europe tend to centre around castles, but you don't tend to find castles just plonked anywhere on the landscape. Edinburgh Castle is a good example because:

  1. I think it looks awesome. Look at the way it seems to just grow out of the rock of those cliffs!
  2. It's pretty much unassailable from every direction but one (I think I mentioned the cliffs);
  3. It's on a raised vantage point with a decent line of sight to just about every direction of approach.

It's not the most castle-ey looking castle and it lacks, for instance:

  1. A moat;
  2. The sort of tower Rapunzel might hang out in.

But I think it makes a reasonable example here. I think this is a good rule of thumb: a castle should look good and be well situated (defensibly speaking).

Another feature which population centres tend to spring up around are harbors. They're very important for trade, thus they attract people. Wikipedia served up a reasonable example:

Rule of thumb number one for a harbor: it should be at the intersection of the land and the sea, ideally. If we're playing in a fantasy sand pit this isn't actually the only option, but that's a story for another day. The nature of the coast is important as well, though. You need reasonably deep water right next to the land, but not too deep. Lastly, and just as importantly: it should provide shelter. The boats in the harbor need to be able to survive the harsh weather the sea sometimes serves up. A sheltered cove with high cliffs to each side sounds about right, no?

The last kind of feature I'm thinking of here is again something quite important to trade: the bridging point. You need to get your trade caravan across the river (or gorge) which separates the harbor and the castle (for example), thus you need to cross the bridge. The bride spans the river at a conveniently narrow point and it's the only one for miles. Thus, the bridge becomes a nexus of activity and a town springs up there. Over time the town increases in size and more bridges get built. Before you know it... BOOM, Florence!

This is, of course, just the tip of the ice berg. We've not even talked about churches, cathedrals, monasteries, oases, and any number of geological features.

Another question, of course is how to go about actual generating the population centres themselves. Well, I'm going to talk more about this later, when I actually get around to talking some other people doing some procedural content related stuff, but here's a little something to wet your appetite:

{% include youtube.html video="MG41yYBD-rE" %}

Cool, no? More about procedural city generation from me later (I don't want to get too far ahead of myself), but you can read more about this project at this excellent series of blogs. Start at the beginning, and be ready to loose a good hour of your time.