Arms following mouse but resulting a curve motion

asydisco · December 1, 2025, 12:33pm

local runService = game:GetService("RunService")
local players = game:GetService("Players")
local userInputService = game:GetService("UserInputService")
local replicateStorage = game:GetService("ReplicatedStorage")

local lookRemote = replicateStorage.Remotes.Character.LookAt

local player = players.LocalPlayer
local mouse = player:GetMouse()

local character = player.Character or player.CharacterAdded:Wait()
local root = character:WaitForChild("HumanoidRootPart")
local humanoid = character:WaitForChild("Humanoid")
local torso = character:WaitForChild("Torso")

local rightShoulder = torso:WaitForChild("Right Shoulder")
local leftShoulder = torso:WaitForChild("Left Shoulder")
local neck = torso:WaitForChild("Neck")

local turnSpeed = 0.05
local aimingState = false

local RC0_Origin = CFrame.new(1, 0.5, 0, 0, 0, 1, 0, 1, 0, -1, 0, 0)
local LC0_Origin = CFrame.new(-1, 0.5, 0, 0, 0, -1, 0, 1, 0, 1, 0, 0)
local Neck_Origin = CFrame.new(0, 1, 0, -1, 0, 0, 0, 0, 1, 0, 1, -0)

local gunAttach 
local Gun_C0_Origin 
local Gun_C1_Origin

local HandOffset = CFrame.new(0, -0.5, -1) * CFrame.Angles(0, math.rad(-90), 0)

character:GetAttributeChangedSignal("Aiming"):Connect(function()
	aimingState = character:GetAttribute("Aiming")
	humanoid.AutoRotate = not aimingState

	if aimingState then
		gunAttach = torso:FindFirstChild("GunAttach")
		if gunAttach then
			Gun_C0_Origin = gunAttach.C0
			Gun_C1_Origin = gunAttach.C1
		end
	end

	if not aimingState then
		rightShoulder.C0 = RC0_Origin
		leftShoulder.C0 = LC0_Origin
		neck.C0 = Neck_Origin

		if gunAttach and Gun_C0_Origin and Gun_C1_Origin then
			gunAttach.C0 = Gun_C0_Origin
			gunAttach.C1 = Gun_C1_Origin
		end
	end
end)

runService.RenderStepped:Connect(function()
	if not aimingState then return end

	local hitPos = mouse.Hit.Position
	if not hitPos then return end
	local angle = math.asin(mouse.Origin.LookVector.Y)
	local rightArmRotation = RC0_Origin * CFrame.Angles(0, 0, angle)
	local leftArmRotation = LC0_Origin * CFrame.Angles(0, 0, -angle)
	local neckRotation = Neck_Origin * CFrame.Angles(-angle, 0, 0)

	rightShoulder.C0 = rightShoulder.C0:Lerp(rightArmRotation, turnSpeed)
	leftShoulder.C0 = leftShoulder.C0:Lerp(leftArmRotation, turnSpeed)
	neck.C0 = neck.C0:Lerp(neckRotation, turnSpeed)
		
	if gunAttach then
		gunAttach.C1 = CFrame.new() 
		gunAttach.C0 = rightShoulder.C0 * HandOffset
	end

	local flatTarget = Vector3.new(hitPos.X, root.Position.Y, hitPos.Z)
	local targetCF = CFrame.lookAt(root.Position, flatTarget)
	root.CFrame = root.CFrame:Lerp(targetCF, turnSpeed)
	
	--lookRemote:FireServer(angle)
end)

Currently this is my code for the rotation, but somehow when i point up or down my arms would eventually got curved.

Ive read several posts, but could not found any solutions.

Sqowly · December 2, 2025, 9:02am

so put a math.clamp() on how far the arms rotate

asydisco · December 2, 2025, 12:34pm

could you provide an example? I dont quite get it

Sqowly · December 3, 2025, 1:41am

local runService = game:GetService("RunService")
local players = game:GetService("Players")
local userInputService = game:GetService("UserInputService")
local replicateStorage = game:GetService("ReplicatedStorage")

local lookRemote = replicateStorage.Remotes.Character.LookAt

local player = players.LocalPlayer
local mouse = player:GetMouse()

local character = player.Character or player.CharacterAdded:Wait()
local root = character:WaitForChild("HumanoidRootPart")
local humanoid = character:WaitForChild("Humanoid")
local torso = character:WaitForChild("Torso")

local rightShoulder = torso:WaitForChild("Right Shoulder")
local leftShoulder = torso:WaitForChild("Left Shoulder")
local neck = torso:WaitForChild("Neck")

local turnSpeed = 0.05
local aimingState = false

local RC0_Origin = CFrame.new(1, 0.5, 0, 0, 0, 1, 0, 1, 0, -1, 0, 0)
local LC0_Origin = CFrame.new(-1, 0.5, 0, 0, 0, -1, 0, 1, 0, 1, 0, 0)
local Neck_Origin = CFrame.new(0, 1, 0, -1, 0, 0, 0, 0, 1, 0, 1, -0)

local gunAttach 
local Gun_C0_Origin 
local Gun_C1_Origin

local HandOffset = CFrame.new(0, -0.5, -1) * CFrame.Angles(0, math.rad(-90), 0)

character:GetAttributeChangedSignal("Aiming"):Connect(function()
	aimingState = character:GetAttribute("Aiming")
	humanoid.AutoRotate = not aimingState

	if aimingState then
		gunAttach = torso:FindFirstChild("GunAttach")
		if gunAttach then
			Gun_C0_Origin = gunAttach.C0
			Gun_C1_Origin = gunAttach.C1
		end
	end

	if not aimingState then
		rightShoulder.C0 = RC0_Origin
		leftShoulder.C0 = LC0_Origin
		neck.C0 = Neck_Origin

		if gunAttach and Gun_C0_Origin and Gun_C1_Origin then
			gunAttach.C0 = Gun_C0_Origin
			gunAttach.C1 = Gun_C1_Origin
		end
	end
end)

runService.RenderStepped:Connect(function()
	if not aimingState then return end

	local hitPos = mouse.Hit.Position
	if not hitPos then return end
	local angle = math.asin(mouse.Origin.LookVector.Y)
	local rightArmRotation = math.clamp(RC0_Origin * CFrame.Angles(0, 0, angle), RC0_Origin, CFrame.new(25, 20, 25)) -- idk at what point your arms start breaking so you could just change these CFrame coordinates.
	local leftArmRotation = math.clamp(LC0_Origin * CFrame.Angles(0, 0, -angle), RC0_Origin, CFrame.new(25, 20, 25)) -- same here.
	local neckRotation = Neck_Origin * CFrame.Angles(-angle, 0, 0) -- and if It ends up happening with the neck you could do the same thing.

	rightShoulder.C0 = rightShoulder.C0:Lerp(rightArmRotation, turnSpeed)
	leftShoulder.C0 = leftShoulder.C0:Lerp(leftArmRotation, turnSpeed)
	neck.C0 = neck.C0:Lerp(neckRotation, turnSpeed)
		
	if gunAttach then
		gunAttach.C1 = CFrame.new() 
		gunAttach.C0 = rightShoulder.C0 * HandOffset
	end

	local flatTarget = Vector3.new(hitPos.X, root.Position.Y, hitPos.Z)
	local targetCF = CFrame.lookAt(root.Position, flatTarget)
	root.CFrame = root.CFrame:Lerp(targetCF, turnSpeed)
	
	--lookRemote:FireServer(angle)
end)

Let me know if it works or not, I cant use my computer right now.

asydisco · December 3, 2025, 1:45am

Math.clamp expected a number, not cframe
But i will send a video so it will let you know what really happened

asydisco · December 3, 2025, 1:48am

External Media

Here is the video

Sqowly · December 3, 2025, 2:07am

local runService = game:GetService("RunService")
local players = game:GetService("Players")
local userInputService = game:GetService("UserInputService")
local replicateStorage = game:GetService("ReplicatedStorage")

local lookRemote = replicateStorage.Remotes.Character.LookAt

local player = players.LocalPlayer
local mouse = player:GetMouse()

local character = player.Character or player.CharacterAdded:Wait()
local root = character:WaitForChild("HumanoidRootPart")
local humanoid = character:WaitForChild("Humanoid")
local torso = character:WaitForChild("Torso")

local rightShoulder = torso:WaitForChild("Right Shoulder")
local leftShoulder = torso:WaitForChild("Left Shoulder")
local neck = torso:WaitForChild("Neck")

local turnSpeed = 0.05
local aimingState = false

local RC0_Origin = CFrame.new(1, 0.5, 0, 0, 0, 1, 0, 1, 0, -1, 0, 0)
local LC0_Origin = CFrame.new(-1, 0.5, 0, 0, 0, -1, 0, 1, 0, 1, 0, 0)
local Neck_Origin = CFrame.new(0, 1, 0, -1, 0, 0, 0, 0, 1, 0, 1, -0)

local gunAttach 
local Gun_C0_Origin 
local Gun_C1_Origin

local HandOffset = CFrame.new(0, -0.5, -1) * CFrame.Angles(0, math.rad(-90), 0)

character:GetAttributeChangedSignal("Aiming"):Connect(function()
	aimingState = character:GetAttribute("Aiming")
	humanoid.AutoRotate = not aimingState

	if aimingState then
		gunAttach = torso:FindFirstChild("GunAttach")
		if gunAttach then
			Gun_C0_Origin = gunAttach.C0
			Gun_C1_Origin = gunAttach.C1
		end
	end

	if not aimingState then
		rightShoulder.C0 = RC0_Origin
		leftShoulder.C0 = LC0_Origin
		neck.C0 = Neck_Origin

		if gunAttach and Gun_C0_Origin and Gun_C1_Origin then
			gunAttach.C0 = Gun_C0_Origin
			gunAttach.C1 = Gun_C1_Origin
		end
	end
end)

runService.RenderStepped:Connect(function()
	if not aimingState then return end

	local hitPos = mouse.Hit.Position
	if not hitPos then return end
	local angle = math.asin(mouse.Origin.LookVector.Y)

	local rightArmRotation = RC0_Origin * CFrame.Angles(0, 0, math.clamp(angle, 5, 30)
	local leftArmRotation = LC0_Origin * CFrame.Angles(0, 0, math.clamp(-angle, -5, -30)
	local neckRotation = Neck_Origin * CFrame.Angles(math.clamp(-angle, -5, -25), 0, 0) 
        -- adjust clamp minimum and maximum values as needed.

	rightShoulder.C0 = rightShoulder.C0:Lerp(rightArmRotation, turnSpeed)
	leftShoulder.C0 = leftShoulder.C0:Lerp(leftArmRotation, turnSpeed)
	neck.C0 = neck.C0:Lerp(neckRotation, turnSpeed)
		
	if gunAttach then
		gunAttach.C1 = CFrame.new() 
		gunAttach.C0 = rightShoulder.C0 * HandOffset
	end

	local flatTarget = Vector3.new(hitPos.X, root.Position.Y, hitPos.Z)
	local targetCF = CFrame.lookAt(root.Position, flatTarget)
	root.CFrame = root.CFrame:Lerp(targetCF, turnSpeed)
	
	--lookRemote:FireServer(angle)
end)

Let me know if this works, I’ve got one more solution in my head.

asydisco · December 3, 2025, 2:12am

Well it does work, but not really what i wanted. Your script do limit the arm rotation but like the arms should be straighten when looking up or down, but it is doing a curve when the mouse point up or down.

asydisco · December 3, 2025, 2:18am

This is my game

This is their

It does not curve

Sqowly · December 3, 2025, 2:24am

You could try lowering the Max Value on the Clamp to something other than the: 30, -30, -25 numbers to prevent it from going too far out

asydisco · December 3, 2025, 3:12am

I tried a few value but it would keep limiting my character arms from going up. I dont think math.clamp is a solution

Sqowly · December 3, 2025, 3:47am

Are you making sure that the LookAt vector for the arms are pointed in the direction of the mouse.

asydisco · December 3, 2025, 12:20pm

I think so, isnt that is what the script are doing?

asydisco · December 4, 2025, 2:17pm

I managed to make the same effect in first person( from other people works ), otherwise in third person i literally have no idea.