ok

function findpartsnear(part)
    local parts = {}

    local rays = {
        ray1 = Ray.new(part.Position, Vector3.new(part.Position.X, part.Position.Y, part.Position.Z - 7 ))
        ray2 = Ray.new(part.Position, Vector3.new(part.Position.X, part.Position.Y, part.Position.Z + 7 ))
        ray3 = Ray.new(part.Position, Vector3.new(part.Position.X, part.Position.Y - 7, part.Position.Z))
        ray4 = Ray.new(part.Position, Vector3.new(part.Position.X, part.Position.Y + 7, part.Position.Z))
        ray5 = Ray.new(part.Position, Vector3.new(part.Position.X - 7, part.Position.Y, part.Position.Z))
        ray6 = Ray.new(part.Position, Vector3.new(part.Position.X + 7, part.Position.Y, part.Position.Z))
    {

    for i, ray in pairs(rays) do
        local part, position = workspace:FindPartOnRay(ray, part)
        if part then
            table.insert(parts, i, part)
        end
    end

    return parts
end

function findabove(part)
    local ray = Ray.new(part.Position, Vector3.new(0, 7, 0))
    return workspace:FindPartOnRay(ray, part)
end

function checkItem(part, material, color)
    if part.Material == material and part.BrickColor == color then
        return true
    end
    return false
end

local threshold = 30
local snowthreshold = 145
local grassthreshhold = 0
local folder = workspace.Terrain
local maxX = 150
local maxY = 100
local maxZ = 150
local maxnoise = 41
local amplitude = 20
local blocksize = 4

function generate(seed)
    for x = -maxX, maxX do
        for z = -maxZ, maxZ do
            for y = maxY, 0, -1 do
                local xnoise = math.noise(y / maxnoise, z / maxnoise, seed) * amplitude
                local ynoise = math.noise(x / maxnoise, z / maxnoise, seed) * amplitude
                local znoise = math.noise(x / maxnoise, y / maxnoise, seed) * amplitude
                local density = xnoise + ynoise + znoise + y

                if density < threshold then
                    local part = Instance.new("Part")
                    part.Anchored = true
                    part.Size = Vector3.new(blocksize, blocksize, blocksize)
                    part.CFrame = CFrame.new(x * blocksize, y * blocksize, z * blocksize)
                    local partabove = findabove(part)

                    if part.Position.Y >= snowthreshold then
                        part.Material = Enum.Material.Slate
                        part.BrickColor = BrickColor.new("Institutional white")
                    elseif part.Position.Y >= grassthreshhold then
                        part.Material = Enum.Material.Grass
                        part.BrickColor = BrickColor.new("Camo")
                    end

                    local grass = check(partabove, Enum.Material.Grass, BrickColor.new("Camo"))
                    local stone = check(partabove, Enum.Material.Slate, BrickColor.new("Medium stone grey"))
                    if (partabove(part)) and (grass or stone) then
                        part.Material = Enum.Material.Slate
                        part.BrickColor = BrickColor.new("Medium stone grey")
                    end

                    part.Parent = folder
                end
            end
        end
    end
end

generate(math.random())