World and levels › Vegetation and placement
Biomes: how a forest is built
Know first: What real land looks like
Nothing in nature grows in an even carpet, and this lesson shows why. A forest is built in layers, and its trees compete for light. It gets colder with height. A south-facing slope is drier than a north-facing one, water has its own kind of forest, and the forest edge is a strip, not a line. Trees stand in groups, and old ones stand next to young ones. These are the rules of nature, and later they become the rules a computer uses to place a forest in a game.
Why this matters
A beginner’s forest is usually trees scattered across the map at random, equally thick everywhere, like seeds on a table. They are all the same size and the same species, as thick on the ridge as in the hollow, with the same dense grass under every tree. A forest like that does not look like a forest, even if each tree is beautiful. The eye sees a carpet at once.
A real forest can be read from far away. It shows where the water is, where the ground is high and where a fire once burned, and the player uses it to find the river, the path and the clearing. So the rules of nature are not decoration. They are the language the land uses to describe itself.
Together, the rules for one patch of the world (which plants grow where, and how thickly) are called a biome. Nobody invented them: each plant takes the place where it can survive. The sections below go through the rules a biome is built from.