Invalid Argument #2 to 'new' Vector 3 Expected got Nil?

Help and Feedback Scripting Support
#1

i’m trying to make a knockback script on a tool but that error appears

Script Code:

local tool = script.Parent

local remote = game.ReplicatedStorage:WaitForChild("Hitted")

remote.OnServerEvent:Connect(function(plr, target)
	if target then
		local mouse = plr:GetMouse()
		if target.Parent:FindFirstChild("Humanoid") then
			local root = target.Parent.HumanoidRootPart
			local velocity = Instance.new("BodyVelocity")
			velocity.MaxForce = Vector3.new(9999999,9999999,9999999)
			velocity.Velocity = CFrame.new(plr.Character.HumanoidRootPart.Position, Vector3, mouse).lookVector * 5
			velocity.Parent = root
			wait(0.5)
			velocity:Destroy()
		end
	end
end)

Error Message Is

Vector3 Expected Got CFrame

Any Help Will Work And Post With The Script

#2

Which line gives the error?

1 Like
#3

it’s on line 12

#4

wait() doesn’t take vector3…

#5

The BodyVelocity velocity property requires Vector3 value not CFrame.

The property determines the goal velocity. Not direction.

#7

Can you be more specific on what you’re trying to achieve? To create a knockback relative to the mouse position, you’ll have to get the direction between the mouse 3D position and the character’s position by normalizing the difference between (goal-origin) and then negating it. Also, .Velocity receives a Vector3, not a CFrame, that’s why you’re getting the error.

If you want to perform the knockback on the target NPC/Character, it’s as simple as replacing the root part and creating the BodyVelocity inside of it.

local function DeleteBody(bodyvelocity)
	bodyvelocity:Destroy()
end

local function CreateBody()
	local BodyVelocity = Instance.new("BodyVelocity")
	BodyVelocity.Velocity = (-(Mouse.Hit.Position-HRP.Position).Unit * 50) + Vector3.new(0, 5, 0)-- Adding to the Y axis to elevate the character
	BodyVelocity.Parent = HRP

	task.delay(.5, DeleteBody, BodyVelocity) -- you can also destroy it with Debris
end

#8

Part.Velocity needs a Vector3 Value. Try using CFrame.Position

#9

You can’t get the player’s mouse from a server script.

https://developer.roblox.com/en-us/api-reference/function/Player/GetMouse

Not to mention you’re trying to pass the mouse object itself as an argument to the CFrame class constructor function.

1 Like
#10 
local tool = script.Parent

local remote = game.ReplicatedStorage:WaitForChild("Hitted")

remote.OnServerEvent:Connect(function(plr, target)
	if target then
		local mouse = plr:GetMouse()
		if target.Parent:FindFirstChild("Humanoid") then
			local root = target.Parent.HumanoidRootPart
			local velocity = Instance.new("BodyVelocity")
			velocity.MaxForce = Vector3.new(9999999,9999999,9999999)
			velocity.Velocity = Vector3.new(plr.Character.HumanoidRootPart.Position, 0, mouse).lookVector * 5
			velocity.Parent = root
			wait(0.5)
			velocity:Destroy()
		end
	end
end)

BodyVelocity expects a Vector3, not CFrame, hence the error. (Line 12)

In addition, as Forummer said, you can’t get a players mouse from a server script.

#11

You cannot derive lookVector from a Vector3.
https://developer.roblox.com/en-us/api-reference/datatype/CFrame