Basically you can generate 2D nosie and 3D(The pics you saw from my tweets were generated using 3D noise)..


First youll need a scale or frequency as some people might say. This will control how wavy your noise will be. Second youll need a amplitude value. This will basically control how spiky/tall the noise will be. Third youll need a seed if you want random results everytime



Generate basic 2D noise:

-- // You need to tweak the variables to get the results you want

local Scale = 20 -- // How wavy your noise will be
local Amplitude = 50 -- // How spiky/Tall your nosie will be

local Seed = math.random() -- // Seed is like a key


local function Generate2D(X, Y)
    return math.noise(X / Scale, Y / Scale, Seed) * Amplitude -- // Generate a new noise with out variables
end)

for x = 1, 15 do
    for y = 1, 15 do
            local Noise = Generate2D(x, y)
            local P = game.ServerStorage.Part:Clone()
            P.Position = Vector3.new(x * 4, Noise, y * 4) -- // Multiply by your block size to space them out and position                                                  the block on the noise scale
            P.Parent = game.Workspace.Terrain
        end
    end
end


-- // Generate 3D Noise(The fun stuff omg)
local Scale = 20
local Amplitude = 50

local Seed = math.random()


local function Generate3D(X, Y, Z)
-- // Were basically creating three 2nd noises and then combining them into a 3D one
    local XN = math.noise(X / Scale, Z / Scale, Seed) * Amplitude
    local YN = math.noise(Y / Scale, X / Scale, Seed) * amplitude
    local ZN = math.noise(Y / Scale, Z / Scale, Seed) * Amplitude

    local Final_Noise = XN + YN + ZN + Y

    return Final_Noise
end)


for x = 1, 15 do
    for y = 1, 15 do
        for z = 1, 15 do
            local Noise = Generate3D(x, y, z)

            if Noise < .5 then
                local P = game.ServerStorage.P:Clone()
                P.Position = Vector3.new(x * 4, y * 4, z * 4)
                P.Parent = game.Workspace.Terrai
            end
        end
    end
end