Smoothen Terrain

tonyngo120 · April 20, 2022, 4:13pm

I want to make my terrain smoother. What I mean is that when I generate terrain using my script, it’s all bumpy compared to the Roblox article’s script. How can I achieve this smoothness? I can provide my code if needed.

my terrain

roblox’s terrain

local render = 200
local chunkheight = 50
local chunks = {}
local hillwidth = 100

local function makechunk(x, z)
	local y = math.noise(math.random(), x/hillwidth, z/hillwidth) * chunkheight
	local position = CFrame.new(x, 0, z)
	local size = Vector3.new(4 , (y + chunkheight), 4)
	workspace.Terrain:FillBlock(position, size, Enum.Material.Snow)
end

local function check(Root)
	for x = -render, render, 4 do
		local renderedx = math.floor(x + Root.Position.X)
		if not chunks[renderedx] then
			chunks[renderedx] = {}
		end
		for z = -render, render, 4 do
			local renderedz = math.floor(z + Root.Position.Z)
			if not chunks[renderedx][renderedz] then
				chunks[renderedx][renderedz] = {}
				makechunk(renderedx, renderedz)
			end
		end
	end
end

while true do
	for i, v in ipairs(game.Players:GetPlayers()) do
		if v.Character then
			if v.Character.HumanoidRootPart then
				check(v.Character.HumanoidRootPart)
			end
		end
	end
	wait(1)
end

my code

5uphi · April 20, 2022, 4:42pm

i think your main problem is your not aligning the block with the terrain

try changing

local position = CFrame.new(x, 0, z)

to

local position = CFrame.new(x + 2, 0, z + 2)

but you can only go so far with Terrain:FillBlock

because you dont have control over the occupancy and you can run into problems when adding water

i would recommend using
https://developer.roblox.com/en-us/api-reference/function/Terrain/WriteVoxels

but then you have to calculate occupancy manually

if you edit this project

you will find a script in there that generates terrain and you can see how im using Terrain:WriteVoxels in there

but if your feeling lazy you could just use my plugin

tonyngo120 · April 20, 2022, 4:48pm

Thanks for reply.

Tried that but my terrain is still rough. I’m sure I won’t be adding water but I’ll check out your plugin and view the script. I prefer not to use plugins that do the work for me otherwise I won’t learn anything.

I’ll try it with other values to see if that works.

5uphi · April 20, 2022, 4:50pm

here is a version that uses workspace.Terrain:FillBlock

local distance = 16
local chunkSize = 16
local updateDistance = 128
local positionX = math.huge
local positionZ = math.huge
local heightData = {}
local loaded = {}

GetHeight = function(x, z)
	if heightData[x] == nil then heightData[x] = {} end
	if heightData[x][z] ~= nil then return heightData[x][z] end	
	local height = 0
	height += math.noise(x * 0.01, 0, z * 0.01) * 40
	height += math.noise(x * 0.04, 0, z * 0.04) * 10
	heightData[x][z] = height
	return height
end

Load = function(x, z)
	local minimum = math.huge
	local maximum = -math.huge
	for xx = x-1, x+1 do
		for zz = z-1, z+1 do
			local height = GetHeight(xx, zz)
			minimum = math.min(minimum, height)
			maximum = math.max(maximum, height)
		end
	end
	local slope = maximum - minimum
	local height = heightData[x][z]
	local thickness = height - minimum + 6
	local position = Vector3.new(x * 4, height, z * 4)
	local cFrame = CFrame.new(x * 4 + 2, height - thickness / 2, z * 4 + 2)
	local size = Vector3.new(4, thickness, 4)
	if slope < 1 then
		workspace.Terrain:FillBlock(cFrame, size, Enum.Material.Mud)
	else
		workspace.Terrain:FillBlock(cFrame, size, Enum.Material.Sand)
	end
	if height >= 0 then return end
	thickness = -height
	local cFrame = CFrame.new(x * 4 + 2, height + thickness / 2, z * 4 + 2)
	local size = Vector3.new(4, thickness, 4)
	workspace.Terrain:FillBlock(cFrame, size, Enum.Material.Water)
end

LoadChunk = function(chunkX, chunkZ)
	if loaded[chunkX] == nil then loaded[chunkX] = {} end
	if loaded[chunkX][chunkZ] ~= nil then return end
	loaded[chunkX][chunkZ] = true
	local startX = chunkX * chunkSize
	local startZ = chunkZ * chunkSize
	local endX = startX + chunkSize - 1
	local endZ = startZ + chunkSize - 1
	for x = startX, endX do
		for z = startZ, endZ do
			Load(x, z)
		end
	end
	wait()
end

LoadChunks = function(chunkX, chunkZ)
	local x, z = chunkX, chunkZ
	local dx, dz = 1, 0
	local passed, length = 0, 1
	LoadChunk(x, z)
	for i = 1, (distance * 2 + 1) * (distance * 2 + 1) - 1 do
		x += dx z += dz
		if Vector2.new(chunkX - x, chunkZ - z).Magnitude < distance + 0.5 then LoadChunk(x, z) end
		passed += 1
		if passed == length then passed = 0 dx, dz = -dz, dx if dz == 0 then length += 1 end end
	end
end

workspace.CurrentCamera:GetPropertyChangedSignal("Focus"):Connect(function()
	local x = workspace.CurrentCamera.Focus.Position.X
	local z = workspace.CurrentCamera.Focus.Position.Z
	if Vector2.new(positionX - x, positionZ - z).Magnitude < updateDistance then return end
	positionX, positionZ = x, z
	LoadChunks(math.floor(x / 4 / chunkSize), math.floor(z / 4 / chunkSize))
end)

tonyngo120 · April 20, 2022, 4:54pm

Thanks for the reply.

Are you able to explain how the script works and why you divided by 4 in certain parts?
Also how did you make the terrain so smooth?

5uphi · April 20, 2022, 5:06pm

so you can think of the terrain like this

and each cube is 4x4x4 studs in size so thats why im dividing by 4

the main part of that code that you need to look at is

local cFrame = CFrame.new(x * 4 + 2, height - thickness / 2, z * 4 + 2)
local size = Vector3.new(4, thickness, 4)
workspace.Terrain:FillBlock(cFrame, size, Enum.Material.Mud)

but i dont recommend doing it with workspace.Terrain:FillBlock

in this project you will find the better workspace.Terrain:WriteVoxels method that i used

and this better method allowed me to get smooth underwater terrain but it might even might effect terrain above water a little

tonyngo120 · April 20, 2022, 5:13pm

Why did you +2 when you multiply by 4?
Also if terrain is on a 4x4x4 grid then what happens if you create terrain with a 1, 1, 1 size?

5uphi · April 20, 2022, 5:22pm

maybe this will help

here you can see the terrain occupancy

each grid is 4 by 4 studs

and if the grid is full then the occupancy is set to 1
if the grid is 50% full then the occupancy is set to 0.5

you cant have terrain that is 1 by 1 in size you can have a 4 by 4 with a low amount of occupancy that will make it feel like a 1 by 1 but its a 4 by 4 with a low occupancy

the reason i did +2 is to align the fillblock with the 4 by 4 grid so that it will set the occupancy to 1 if you are not aligned then the occupancy will be wrong

and here you can see what it looks like as the occupancy gets lower

tonyngo120 · April 20, 2022, 5:25pm

Thanks for the explanation. It makes sense.

Though I still don’t know why my terrain is still rough. Do you have any ideas?

5uphi · April 20, 2022, 6:03pm

it might be the material your using try with sand and see if you get the same problem

tonyngo120 · April 20, 2022, 6:09pm

the problem persists with sand as well

5uphi · April 20, 2022, 6:11pm

then the only thing i can think of it that your not aligning the workspace.Terrain:FillBlock with the grids of the terrain correctly

tonyngo120 · April 20, 2022, 6:16pm

What can I do to fix it then??

5uphi · April 20, 2022, 6:33pm

so the problem is most likely

 local renderedx = math.floor(x + Root.Position.X)

i think this is not positioning the block correctly

you can use

… -6, -2, 2, 6, 10, 14 …
these are all positions you can use for workspace.Terrain:FillBlock

tonyngo120 · April 20, 2022, 7:34pm

I try that and then get this. u can see from the output that all the values are 4n-2. i can send my code

tonyngo120 · April 20, 2022, 7:36pm

grass version

tonyngo120 · April 20, 2022, 7:37pm

--[[]]
local render = 200
local chunkheight = 40
local chunks = {}
local hillwidth = 2
local fix = 2

local function makechunk(x, z)
	local y = math.noise (math.random(), x/hillwidth*4, z/hillwidth *4 ) * chunkheight
	x = x * 4 + 2
	z = z * 4 + 2
	print(x, z)
	local position = CFrame.new(x, 0, z)
	local size = Vector3.new(4 , (y + chunkheight), 4)
	workspace.Terrain:FillBlock(position, size, Enum.Material.Grass)
end

local function check(Root)
	for x = -render, render do
		local renderedx = math.floor((x + Root.Position.X)/4)
		renderedx = renderedx
		if not chunks[renderedx] then
			chunks[renderedx] = {}
		end
		for z = -render, render do
			local renderedz = math.floor((z + Root.Position.Z)/4)
			if not chunks[renderedx][renderedz] then
				chunks[renderedx][renderedz] = {}
				makechunk(renderedx, renderedz)
			end
		end
	end
end

while true do
	for i, v in ipairs(game.Players:GetPlayers()) do
		if v.Character then
			if v.Character.HumanoidRootPart then
				check(v.Character.HumanoidRootPart)
			end
		end
	end
	wait(1)
end

Have tried without hillwidth * 4 same result.

5uphi · April 20, 2022, 7:50pm

Ok I see another problem

Your using math.random inside the math.noise function you don’t want to do that

Change math.random to 0

tonyngo120 · April 20, 2022, 7:52pm

Thanks alot
u were very helpful.

this especially helped. thanks!
my terrain is now smooth as butter.

5uphi · April 20, 2022, 7:54pm

Nice I’m happy you got it working