Description
From Random Scattering: Creating Realistic Landscapes:
Two competing methodologies in procedural content generation are teleological and ontogenetic. The teleological approach creates an accurate physical model of the environment and the process that creates the thing generated, and then simply runs the simulation, and the results should emerge as they do in nature.
The ontogenetic approach observes the end results of this process and then attempts to directly reproduce those results by ad hoc algorithms. Ontogenetic approaches are more commonly used in real-time applications such as games. (See "Shattering Reality," Game Developer, August 2006.)
If you are generating a map using Simplex Noise for height, you are using an ontogenetic approach. This is because nothing about the geological processes which result in hills, mountains, and slopes resembles the process used to create the noise, other than the fact that the output can be fractal-like when multiple layers of noise are combined. A teleological analogue to this would be to take a flat height field, distort it by mimicking the movement of plate tectonics (on a large enough scale), and then using a Rain-Drop Algorithm to mimic erosion.
Teleological Algorithms
Ontogenetic Algorithms
PCG Wiki References
External Links
Random Scattering: Creating Realistic Landscapes - Mick West
