local conf = function(obj, ...)
    for _, property in ipairs({...}) do
        obj[property[1]] = property[2]
    end
    return obj
end

local grid = 100
local size = 6
local ticks = 0

local minHill, maxHill = grid / 2, grid

local terrain = Instance.new("Model", Workspace)

local parts = {}

for x = -0.5 * (grid * size), 0.5 * (grid * size), size do
    for z = -0.5 * (grid * size), 0.5 * (grid * size), size do
        ticks = ticks + 1
        if ticks % 200 == 0 then
            wait()
        end
        table.insert(parts, conf(
            Instance.new("Part", terrain),
            {"FormFactor", Enum.FormFactor.Custom},
            {"Position", Vector3.new(x, 0, z)},
            {"Size", Vector3.new(size, 10, size)},
            {"Anchored", true},
            {"TopSurface", Enum.SurfaceType.Smooth}
        ))
    end
end

for i = 1, grid do
    wait()
    local rand = parts[math.random(#parts)]
    local radius = math.random(minHill, maxHill)
    for _, part in ipairs(parts) do
        if (rand.Position - part.Position).magnitude < radius then
            part.Size = part.Size + Vector3.new(0, radius - (rand.Position - part.Position).magnitude, 0)
        end
    end
end

--normalize
local high, low = 0, 2^16

for _, part in ipairs(parts) do
    if part.Size.Y < low then
        low = part.Size.Y
    elseif part.Size.Y > high then
        high = part.Size.Y
    end
end

local ticks = 0

for _, part in ipairs(parts) do
    ticks = ticks + 1
    if ticks % grid == 0 then
        wait()
    end
    part.Size = Vector3.new(size, (grid * 2) * (part.Size.Y - low) / (high - low), size)
    if part.Size.Y <= 0.3 then
        part.BrickColor = BrickColor.new("Bright blue")
    else
        part.BrickColor = BrickColor.new("Camo")
        part.Material = Enum.Material.Grass
    end
end