Lua error : invalid argument #1 to 'new' (Vector3 expected, got Vector2)

Question

I want to make a game that is like skriblio. so I create the gui and tried to connect them. and code the logic I got an error when I try to run my script is there something wrong in my script? the error are in line 12 here is my code

local UserInputService = game:GetService("UserInputService")
local currentTool = "Line" -- Ganti dengan alat default Anda
local currentColor = Color3.new(0, 0, 0) -- Ganti dengan warna default Anda
local canvas = script.Parent -- Ganti dengan objek "canvas" yang sesuai

local function drawLine(startPoint, endPoint)
    local line = Instance.new("Part")
    line.Anchored = true
    line.Material = Enum.Material.SmoothPlastic
    line.BrickColor = BrickColor.new(currentColor)
    line.Size = Vector3.new((startPoint - endPoint).Magnitude, 0.2, 0.2)
    line.CFrame = CFrame.new((startPoint + endPoint) / 2, Vector3.new(endPoint.X, endPoint.Y, 0))
    line.Parent = canvas
end

local function drawCircle(center, radius)
    local circle = Instance.new("Part")
    circle.Anchored = true
    circle.Material = Enum.Material.SmoothPlastic
    circle.BrickColor = BrickColor.new(currentColor)
    circle.Shape = Enum.PartType.Cylinder
    circle.Size = Vector3.new(radius * 2, 0.2, radius * 2)
    circle.CFrame = CFrame.new(center) + Vector3.new(0, 0.1, 0)
    circle.Parent = canvas
end

local function drawFreehand(startPoint, endPoint)
    local line = Instance.new("Part")
    line.Anchored = true
    line.Material = Enum.Material.SmoothPlastic
    line.BrickColor = BrickColor.new(currentColor)
    line.Size = Vector3.new(0.2, 0.2, (startPoint - endPoint).Magnitude)
    line.CFrame = CFrame.new((startPoint + endPoint) / 2, Vector3.new(endPoint.X, endPoint.Y, 0))
    line.Parent = canvas
end

local function erase(startPoint, endPoint)
    -- Dapatkan semua objek anak di dalam "canvas"
    local canvasChildren = canvas:GetChildren()

    -- Iterasi melalui semua objek anak dan periksa apakah mereka berada dalam wilayah yang ditentukan
    for _, child in ipairs(canvasChildren) do
        if child:IsA("BasePart") then
            local position = child.Position
            if position.X >= startPoint.X and position.X <= endPoint.X and
                position.Y >= startPoint.Y and position.Y <= endPoint.Y then
                child:Destroy()
            end
        end
    end
end
UserInputService.InputBegan:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.MouseButton1 then
        local startPoint = UserInputService:GetMouseLocation()

        if currentTool == "Line" then
            -- Menggambar garis
            UserInputService.InputEnded:Wait()
            local endPoint = UserInputService:GetMouseLocation()
            drawLine(startPoint, endPoint)
        elseif currentTool == "Circle" then
            -- Menggambar lingkaran
            UserInputService.InputEnded:Wait()
            local endPoint = UserInputService:GetMouseLocation()
            local radius = (startPoint - endPoint).Magnitude
            drawCircle(startPoint, radius)
        elseif currentTool == "Pen" then
            -- Menggambar secara bebas
            local prevPoint = startPoint
            repeat
                local currentPoint = UserInputService:GetMouseLocation()
                drawFreehand(prevPoint, currentPoint)
                prevPoint = currentPoint
                wait()
            until not UserInputService:IsMouseButtonPressed(Enum.UserInputType.MouseButton1)
        elseif currentTool == "Eraser" then
            -- Menghapus
            UserInputService.InputEnded:Wait()
            local endPoint = UserInputService:GetMouseLocation()
            erase(startPoint, endPoint)
        end
    end
end)

my code knowledge is very limited because i'm still learning, what is my problem and what do i need to change?

Answer 1

The error is telling you exactly what is wrong. When you tried to create a CFrame, an object that represents a 3D position and orientation in space, you gave it a Vector2 and the constructor expected a Vector3.

In your drawLine function, you construct a CFrame by averaging the startPoint and endPoint variables, but both of those variables come from UserInputService:GetMouseLocation() which returns a Vector2.

A simple answer might be to try to convert the Vector2 into a Vector3, using the same system as your other Vector3s.

local linePos = (startPoint + endPoint) / 2
line.CFrame = CFrame.new(Vector3.new(linePos.X, linePos.Y, 0), Vector3.new(endPoint.X, endPoint.Y, 0))

But, you have 2D screen coordinates and you are trying to use them to place an object into a 3D space. One way to do this is to raycast into the space and try to find an object that it hits. A large block acting as a canvas would be recommended here. So instead of UserInputService:GetMouseLocation(), try using the Mouse class. It comes with a Hit property that will give you a CFrame of a collision point inside the workspace. You can use that to get your Vector3s.

UserInputService.InputBegan:Connect(function(input)
    if input.UserInputType == Enum.UserInputType.MouseButton1 then
        local mouse = game.Players.LocalPlayer:GetMouse()
        local startPoint = mouse.Hit.p

        if currentTool == "Line" then
            -- Menggambar garis
            UserInputService.InputEnded:Wait()
            local endPoint = mouse.Hit.p
            drawLine(startPoint, endPoint)
        elseif currentTool == "Circle" then
            -- Menggambar lingkaran
            UserInputService.InputEnded:Wait()
            local endPoint = mouse.Hit.p
            local radius = (startPoint - endPoint).Magnitude
            drawCircle(startPoint, radius)
        elseif currentTool == "Pen" then
            -- Menggambar secara bebas
            local prevPoint = startPoint
            repeat
                local currentPoint = mouse.Hit.p
                drawFreehand(prevPoint, currentPoint)
                prevPoint = currentPoint
                wait()
            until not UserInputService:IsMouseButtonPressed(Enum.UserInputType.MouseButton1)
        elseif currentTool == "Eraser" then
            -- Menghapus
            UserInputService.InputEnded:Wait()
            local endPoint = mouse.Hit.p
            erase(startPoint, endPoint)
        end
    end
end)