How to make the (Motor6D) Neck turn relative to its rootpart's axis

I am trying to code a creature which will look at you, but I would like its head not to turn upwards or downwards, only side to side


This may look fine at first, but things get weird once I orientate it.

The Green arrow indicates where it should look

The Neck turns based off the world’s axis, and since i am terrible at cframing, i honestly don’t know what to do to make it so it turns relative to its torso.


local function worldCFrameToC0ObjectSpace(motor6DJoint,worldCFrame)
	local part1CF = motor6DJoint.Part1.CFrame
	local c1Store = motor6DJoint.C1
	local c0Store = motor6DJoint.C0
	local relativeToPart1 =c0Store*c1Store:Inverse()*part1CF:Inverse()*worldCFrame*c1Store
	relativeToPart1 -= relativeToPart1.Position

	local goalC0CFrame = relativeToPart1+c0Store.Position
	return goalC0CFrame

local goalCF = CFrame.lookAt(Head.Position,, Head.Position.Y, Target.Position.Z), UpperTorso.CFrame.UpVector) * CFrame.Angles(math.pi, math.pi, 0)

NeckJoint.C0 = worldCFrameToC0ObjectSpace(NeckJoint, goalCF)
	local Game = game
	local RunService = Game:GetService("RunService")
	local Players = Game:GetService("Players")
	local Player = Players.LocalPlayer
	local Character = Player.Character or Player.CharacterAdded:Wait()
	local Humanoid = Character:FindFirstChildOfClass("Humanoid") or Character:WaitForChild("Humanoid")
	local Root = Character:FindFirstChild("HumanoidRootPart") or Character:WaitForChild("HumanoidRootPart")
	local RigType = Humanoid.RigType.Name
	local Neck
	if RigType == "R6" then
		local Torso = Character:FindFirstChild("Torso") or Character:WaitForChild("Torso")
		Neck = Torso:FindFirstChild("Neck") or Torso:WaitForChild("Torso")
	elseif RigType == "R15" then
		local Head = Character:FindFirstChild("Head") or Character:WaitForChild("Head")
		Neck = Head:FindFirstChild("Neck") or Head:WaitForChild("Torso")
	if not Neck then return end
	local function OnRenderStep()
		Neck.C0 = * Root.CFrame.Rotation * CFrame.Angles(math.pi / 2, math.pi, 0)

WIll likely require a clamp.