Rivers are borders or connections consisting of "watery terrain" that run downhill to regions of water.
SynthesisMethod: make-rivers
This method looks for a border or connection
terrain type with a subtype-x
of river-x
.
then uses the world's elevation data to run rivers downhill
(always choosing the lowest of possible adjacent locations)
until they reach cell terrain with a subtype
> 0.
This method will not run if there are no appropriate terrain types,
nor if there is no elevation data.
TerrainTypeProperty: river-chance
n%
This property is the chance that a river will start in or around a cell of this
terrain type.
Defaults to 0
.
GlobalVariable: river-sink-terrain
t
If the value of this variable is a terrain type, then a cell completely
surrounded by river will be changed to be this type.
Defaults to non-terrain
.
Note that the algorithm computes rivers in a deterministic way,
so high values of river-chance
do not result in tangled rivers.