Perlin noise on ROBLOX

local mapSize = 500
local noise = math.noise
local seed = tick()
local heightMap = table.create(mapSize, table.create(mapSize))
local abs = math.abs
local colorTable = {
    [0] = BrickColor.Blue();
    [1] = BrickColor.new("Beige");
    [2] = BrickColor.Green();
    [3] = BrickColor.DarkGray();
    [4] = BrickColor.White();
}

--SETTINGS

wait(3)

local FREQUENCY =       2;
local REDISTRIBUTION =  1;
local PERSISTANCE =     0.5;
local OCTAVES =         5;
local LACUNARITY =      2;
local AMPLITUDE =       500;

local function ridgeNoise(nx, ny)

    return noise(nx, ny, seed) --2 * (0.5 - abs(0.5 - noise(nx, ny, seed)));

end

local function getBiome(hm)
    if hm < 0.05 then
        return 0
    elseif hm < 0.1 then
        return 1
    elseif hm < 0.2 then
        return 2
    elseif hm < 0.3 then
        return 3
    else
        return 4
    end
end

for x = 1,mapSize do
    if x % 10 == 0 then
        game:GetService("RunService").Heartbeat:Wait()
    end
    for y = 1,mapSize do
        local nx, ny = x/mapSize - 0.5, y/mapSize - 0.5
        local elevation = 0

        for i = 1,OCTAVES do
            local newElev = PERSISTANCE^i * ridgeNoise(nx * FREQUENCY * LACUNARITY^(i-1),ny * FREQUENCY * LACUNARITY^(i-1))

            elevation += newElev

        end

        heightMap[x][y] = math.pow(elevation, REDISTRIBUTION);

        local biome = getBiome(heightMap[x][y])

        local part = Instance.new("Part")
        part.Anchored = true
        part.Size = Vector3.new(1,50,1)
        part.Position = Vector3.new(x, math.clamp(heightMap[x][y],0.05,10000)*AMPLITUDE, y);
        part.BrickColor = colorTable[biome]
        part.Material = Enum.Material.SmoothPlastic
        part.Parent = workspace
    end
end