-- Create a new DynamicMesh instance
local dynamicMesh = Instance.new("DynamicMesh")

-- Function to get perlin noise
local function perlinNoise(x, y, scale, height)
	return math.noise(x * scale, y * scale) * height
end

local size = 50  -- Size of the terrain
local scale = 0.1  -- Scale factor for Perlin noise
local height = 5  -- Height factor for Perlin noise

-- Add vertices based on Perlin noise
local vertices = {}  -- Stores the vertices
local vertexIds = {}  -- Stores the IDs of the vertices
for i = 0, size do
	for j = 0, size do
		local height = perlinNoise(i, j, scale, height)
		local vertex = Vector3.new(i, height, j)
		table.insert(vertices, vertex)
		local vertexId = dynamicMesh:AddVertex(vertex)
		vertexIds[i * (size + 1) + j + 1] = vertexId
		
		dynamicMesh:SetVertexColor(vertexId, BrickColor.new("Bright green").Color)
	end
end

-- Calculate normal of a triangle
local function calculateNormal(v1, v2, v3)
	local u = v2 - v1
	local v = v3 - v1
	return u:Cross(v).Unit
end

-- Stores the normals of the vertices
local normals = {}
for i = 0, size - 1 do
	for j = 0, size - 1 do
		-- Calculate indices
		local index0 = i * (size + 1) + j + 1
		local index1 = i * (size + 1) + j + 2
		local index2 = (i + 1) * (size + 1) + j + 1
		local index3 = (i + 1) * (size + 1) + j + 2

		-- Get vertices
		local v0 = vertices[index0]
		local v1 = vertices[index1]
		local v2 = vertices[index2]
		local v3 = vertices[index3]

		-- Calculate normals of the two triangles and average them
		local n1 = calculateNormal(v0, v1, v2)
		local n2 = calculateNormal(v2, v1, v3)
		local normal = (n1 + n2).Unit

		-- Store the normal
		normals[index0] = normals[index0] and (normals[index0] + normal).Unit or normal
		normals[index1] = normals[index1] and (normals[index1] + normal).Unit or normal
		normals[index2] = normals[index2] and (normals[index2] + normal).Unit or normal
		normals[index3] = normals[index3] and (normals[index3] + normal).Unit or normal
	end
end

-- Add normals to the vertices
for i, vertexId in ipairs(vertexIds) do
	dynamicMesh:SetVertexNormal(vertexId, normals[i])
end

-- Add triangles to form the terrain
for i = 0, size - 1 do
	for j = 0, size - 1 do
		-- Calculate indices
		local index0 = i * (size + 1) + j + 1
		local index1 = i * (size + 1) + j + 2
		local index2 = (i + 1) * (size + 1) + j + 1
		local index3 = (i + 1) * (size + 1) + j + 2

		-- Add triangles
		dynamicMesh:AddTriangle(vertexIds[index0], vertexIds[index1], vertexIds[index2])
		dynamicMesh:AddTriangle(vertexIds[index2], vertexIds[index1], vertexIds[index3])
	end
end

dynamicMesh.Parent = workspace

-- Create a MeshPart from DynamicMesh with Default CollisionFidelity
local meshPart = dynamicMesh:CreateMeshPartAsync(Enum.CollisionFidelity.DynamicPreciseConvexDecomposition)

-- Add the MeshPart to Workspace
meshPart.Parent = workspace

-- Setting some properties of the MeshPart
meshPart.Name = "DynamicMeshPart"
meshPart.Material = Enum.Material.Grass
meshPart.Anchored = true
meshPart.Position = Vector3.new(0, 5, 0)