In short we need a function of the format:

In light of the requirements above, grid values will need to be effectively infinite in number, generated on the fly, have no visible patterns or repeats, and be reproducible across program runs. A grid of points are generated, if the noise is sampled outside of the grid, the pattern is simply repeated this has the advantage of being fast - requiring only an array lookup instead of a random number generation - but has the disadvantage of creating a repeating pattern. Perlin noise, in it's original form is slightly unsuited to this task, due to the fact that the values used at the grid points are precomputed.

Realtime arbitrary generation order: Minecraft terrain is generated on the fly, as the player explores the world, this means that terrain chunks can be generated at any order, at any time, across different play sessions, Minecraft versions, Java versions, generator versions, or even devices.

Technical limits are OK (the same type of limit at the root of Minecraft's fabled '8 times the surface of the earth' claim)

'Infinite' generation: The noise generator should able to generate noise without any built in limits, terrain should not repeat.

By composing multiple noise generators, it will be possible to generate a world.īecause I want this generator to work similarly to Minecraft's world generator, there are a couple of unique requirements: This - and similar coherent randomness algorithms - are useful because they allow us to specify things such as the period (the scale of the noise, in the context of a terrain generator, will allow the generated noise form the basis of things of all scales, from tiny hills to entire continents) and the amplitude (the 'height' of the noise). Perlin noise generation is a technique first engineered to reduce the memory requirements of textures in early computer graphics. Perlin noise is in fact used in a critical role in MInecraft's native generator, as Notch describes in Terrain Generation, Part 1 (of 1). If you visit any online resource about terrain or world generation, chances are good that it will mention Perlin noise and associated 'Coherent Randomness' algorithms.

Minecraft world generator algorithm