A way to get realistic terrain types on a generated map is to
use the Whittaker diagram. This diagram defines the terrain type
from two parameters : temperature and precipitation. You can
easily compute temperature from the latitude, distance from sea
and altitude, but the precipitation is not as intuitive. One way
to get it is to simulate winds. Imagine a point on the map
following the wind. When it is over the sea, it accumulates
water in a waterCount variable. When it travels above land, it
drops a part of its accumulated water at each step. To simulate
orographic rains, the percentage of waterCount that is dropped
on ground is proportional to the land slope in the wind
direction. This method has two benefits over the previous one :
- precipitations are nicely spread from sea to land and don’t
stop a few kilometers after the coast - mountains acts as
barrier for precipitations Now I didn’t try to do some realistic
wind simulation. I simply apply 4 steps, one for each cardinal
direction. This is the altitud