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I've been thinking of making a top-down 2D game with a pseudo-infinite runtime procedural generated world. I've read several articles about procedural generation and, maybe I've misread or misunderstood them, but I have yet to come across one explaining how to divide the world into chunks (like Minecraft apparently does).

Obviously, I need to generate only the part of the world that the player can currently see. If my game is tile-based, for example, I could divide the world into n*n chunks. If the player were at the border of such a chunk, I would also generate the adjacent chunk(s).

What I can't figure out is how exactly do I take a procedural world generation algorithm and only use it on one chunk at a time. For example, if I have an algorithm that generates a big structure (e.g. castle, forest, river) that would spread across many chunks, how can I adjust it to generate only one chunk, and afterwards the adjacent chunks?

I apologize if I completely missed something obvious. Thank you in advance!

liviucmg
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1 Answers1

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Study the Midpoint displacement algorithm. Note that the points all along one side are based on the starting values of the corners. You can calculate them without knowing the rest of the grid.

I used this approach to generate terrain. I needed the edges of each 'chunk' of terrain to line up with the adjacent chunks. Using a variation of the Midpoint displacement algorithm I made it so that the height of each point along the edge of a chunk was calculated based only on values at the two corners. If I needed to add randomness, I seeded a random number generator with data from the two corners. This way, any two adjacent chunks could be generated independently and the edges were sure to match.

You can use approaches for height-maps for other things. Instead of height, the data could determine vegetation type, population density, etc. Instead of a chunks of height map where the hills and valleys match up you can have a vegetation map where the forests match up.

It certainly takes some creative programming for any kind of complex world.

Liam
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  • +1 for Midpoint displacement. It's a very good starting point since it's so easy to implement and understand (and lightning fast too). Only if the artifacts you get from midpoint displacement becomes a problem, it might be worth to look into perlin or simplex noise which are a lot more complex and unintuitive to work with. – Arahman Nov 26 '13 at 00:16