# Seed based terrain generation

Hello! I was looking for some help building a seed-based terrain generation system, like Minecraft. If a world for one player has seed 2, and another player loads a world with the same seed, the same terrain would generate.

I have got some chunks that I could implement. Right now, each chunk (32x32 studs) just needs to be a different brick colour, and different structures should appear (think villages in Minecraft, and other structures, like jungle temples are rarer)

Please let me know if you have any ideas. Thanks!

Iâ€™ll leave you with math.noise, but just know that this is a very complicated subject in more than one aspect, if youâ€™re going for the full concept of Minecraft generation.

Iâ€™ve seen that before, but didnâ€™t understand how it could be utilised.

So the way that seeding works is that it makes your pseudorandom generation the same across each input, for example

``````local seed = 1
Random.new(seed) -- the seed value can be made consistent
Random:NextInt(1, 10) -- this should return a consistent value
--However, Math.noise generates its noise from its inputs, not from the math.randomseed() function
math.noise(x, y, z) will always equal math.noise(x, y, z)
``````

Therefor you can use that seed value to adjust the inputs of Math.noise

``````local seed = 1
local chunksize = 16
local scale = 10.71 -- math.noise only works with floating point numbers, integers will return 0
for x = 0, chunksize do
for y = 0, chunksize do
local height = math.noise((x / scale) * seed, (y/scale) * seed)
end
end
``````

Cheers!

3 Likes

Thanks! Just to ask, how do I make it generate structures with rarity? For it to be consistent across worlds using the same seed, how would it be done?

Youâ€™ll need multiple noise maps for multiple different things. Iâ€™d give more in-depth information as Iâ€™ve worked directly with this sort of thing, but thatâ€™s also a project Iâ€™m still working on (albeit on the back-burner at the moment).

1 Like

Eek. Still donâ€™t really understand it all. Do you have any code examples of using multiple noise maps?

Thereâ€™s a lot of videos on YouTube about using perlin noise in regards to terrain:

Thereâ€™s many more that have nothing to do with Roblox, but can still be relevant.

3 Likes

Thank you! Iâ€™ll take note of this.

Creating structures using noise can be done by using a second noise map with a higher-scale.

So instead of generating noise to get the height of a voxel in a chunk, set your noise inputs based on the chunk position itself. This will allow you to handle things such as biomes and structure generation by using a separate layer of noise.

The code for generating a noise sample is the same, you just have to change the input.

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Just a heads up: this only works if the RNG is called for each thing in the same order every time! If your goal is to have terrain that generates in chunks around the player as they move through the world, for â€śinfiniteâ€ť terrain, then you need to keep careful track of several RNGs to actually get the same result every time.

Just generating the terrain in a fixed number of chunks (and in a fixed order) is a lot of work already so this isnâ€™t the first thing to deal with IMO, but itâ€™s good to know for the future.

1 Like

Ah, thank you - this is starting to make more sense.

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