📝Use gradient noise functions for map generation
Large/3D terrain maps can be generated by layering multiple gradient noise functions. You can use a couple of noise functions with different amplitude and frequency (scale) to generate a height map. (See Fractal noise)
Then additional gradient noise functions can be used to sprinkle additional features: assign different terrain types, add trees and plants. One can use a 3D noise function to add 3D features like caverns.
Pros
- Because noise functions are deterministic, the whole map can be generated incrementally from a seed value. This can be used to generate huge maps without having to store them in full.
Cons
- Noise functions tend to get repetitive, so you need to combine multiple functions.
- It might be hard to generate realistic/interesting terrain with noise functions.