Why does my dash script not propel the player forward?

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1

I am currently trying to make a simple dash script but my knowledge on how linear velocity works against body velocity is limited. Can someone explain what is wrong with the way I scripted the linear velocity?

local UserInputService = game:GetService("UserInputService")

local Character = script.Parent
local HumanoidRootPart = Character:WaitForChild("HumanoidRootPart")
local Humanoid = Character:WaitForChild("Humanoid")

local Attachment = Instance.new("Attachment")
Attachment.Parent = HumanoidRootPart

local Speed = 200
local DashDuration = .2
local Cooldown = 1

local Dashing = false
local LastDash = 0

local Animator = Humanoid:FindFirstChildWhichIsA("Animator")
local Animations = {
	Forwards = Instance.new("Animation");
	Backwards = Instance.new("Animation");
	Right = Instance.new("Animation");
	Left = Instance.new("Animation");
}

Animations.Backwards.AnimationId = "rbxassetid://94244983051609"
Animations.Forwards.AnimationId = "rbxassetid://140245478716706"
Animations.Right.AnimationId = "rbxassetid://83778304105336"
Animations.Left.AnimationId = "rbxassetid://88451953083874"

local function DashAnimation(Direction)
	local AnimationTrack = Animator:LoadAnimation(Animations[Direction])
	AnimationTrack:Play()
	AnimationTrack.Stopped:Connect(function()
		AnimationTrack:Destroy()
	end)
end

local function Dash()
	if Dashing or tick() - LastDash < Cooldown then 
		return 
	end
	Dashing = true
	LastDash = tick()

	local MoveDirection = Humanoid.MoveDirection
	local Direction

	if MoveDirection.Magnitude == 0 then
		Direction = "Backwards"
	elseif math.abs(MoveDirection.Z) > math.abs(MoveDirection.X) then
		Direction = (MoveDirection.Z > 0) and "Forwards" or "Backwards"
	else
		Direction = (MoveDirection.X > 0) and "Right" or "Left"
	end

	DashAnimation(Direction)

	local LinearVelocity = Instance.new("LinearVelocity")
	LinearVelocity.MaxForce = 5000
	LinearVelocity.VectorVelocity = MoveDirection.Unit * Speed
	LinearVelocity.RelativeTo = Enum.ActuatorRelativeTo.Attachment0
	LinearVelocity.Attachment0 = Attachment
	LinearVelocity.Parent = HumanoidRootPart

	wait(DashDuration)
	LinearVelocity:Destroy()
	Attachment:Destroy()
	Dashing = false
end

UserInputService.InputBegan:Connect(function(Input,GameProcessed)
	if GameProcessed then
		return
	end
	if Input.KeyCode == Enum.KeyCode.Q then
		Dash()
	end
end)
2

What’s wrong with it?
Also, LinearVelocity is practically the same as BodyVelocity, except with more things.
First: make sure the LinearVelocity is connected to an attachment on the HumanoidRootPart
Second: make sure the LinearVelocity.RelativeTo is set to Enum.ActuatorRelativeTo.World

3

Few problems. Firstly, your variables need some tuning. 200 speed is overkill. Additionally, you don’t want your relative velocity to be for attachments, as MoveDirection is in the world space. You also destroy your attachment after one dash. The last thing is that you should make sure your force limits aren’t too low. Here is the edited code I made, I also turned off force limits just for convenience.

local UserInputService = game:GetService("UserInputService")

local Character = script.Parent
local HumanoidRootPart = Character:WaitForChild("HumanoidRootPart")
local Humanoid = Character:WaitForChild("Humanoid")

local Attachment = Instance.new("Attachment")
Attachment.Parent = HumanoidRootPart

local Speed = 50
local DashDuration = .5
local Cooldown = 1

local Dashing = false
local LastDash = 0

local Animator = Humanoid:FindFirstChildWhichIsA("Animator")
local Animations = {
	Forwards = Instance.new("Animation");
	Backwards = Instance.new("Animation");
	Right = Instance.new("Animation");
	Left = Instance.new("Animation");
}

Animations.Backwards.AnimationId = "rbxassetid://94244983051609"
Animations.Forwards.AnimationId = "rbxassetid://140245478716706"
Animations.Right.AnimationId = "rbxassetid://83778304105336"
Animations.Left.AnimationId = "rbxassetid://88451953083874"

local function DashAnimation(Direction)
	local AnimationTrack = Animator:LoadAnimation(Animations[Direction])
	AnimationTrack:Play()
	AnimationTrack.Stopped:Connect(function()
		AnimationTrack:Destroy()
	end)
end

local function Dash()
	if Dashing or tick() - LastDash < Cooldown then
		return 
	end
	Dashing = true
	LastDash = tick()

	local MoveDirection = Humanoid.MoveDirection
	local Direction

	if MoveDirection.Magnitude == 0 then
		Direction = "Backwards"
	elseif math.abs(MoveDirection.Z) > math.abs(MoveDirection.X) then
		Direction = (MoveDirection.Z > 0) and "Forwards" or "Backwards"
	else
		Direction = (MoveDirection.X > 0) and "Right" or "Left"
	end

	DashAnimation(Direction)
	local LinearVelocity = Instance.new("LinearVelocity")
	LinearVelocity.ForceLimitsEnabled = false
	LinearVelocity.VectorVelocity = MoveDirection.Unit * Speed
	LinearVelocity.Attachment0 = Attachment
	LinearVelocity.Parent = HumanoidRootPart

	wait(DashDuration)
	LinearVelocity:Destroy()
	Dashing = false
end

UserInputService.InputBegan:Connect(function(Input,GameProcessed)
	if GameProcessed then
		return
	end
	if Input.KeyCode == Enum.KeyCode.Q then
		Dash()
	end
end)