Acceleration script

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#1

i want to achieve a smooth run, where instead of instantly running it has a slow start, but i need the animation to slowly accelerate/decelerate smoothly with it

i have tried various ways to get this to work but none have been successful

local UIS = game:GetService("UserInputService")
local TweenService = game:GetService("TweenService")

local Player = game.Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait()
local Humanoid = Character:WaitForChild("Humanoid")
local Root = Character:WaitForChild("HumanoidRootPart")
local Camera = workspace.CurrentCamera
local Animator = Humanoid:WaitForChild("Animator")

-- Running Configuration
local MaxSpeed = 20 -- Maximum running speed
local AccelerationRate = 0.3 -- Speed increase per cycle
local DecelerationRate = 0.5 -- Speed decrease per cycle
local BaseSpeed = 17 -- Default walking speed
local BaseFOV = 65 -- Default FOV
local MaxFOV = 75 -- Maximum FOV at full speed
local AnimationSpeedMultiplier = 0.7 -- Multiplier for animation speed

-- Animation Setup
local RunAnimation = Instance.new("Animation")
RunAnimation.AnimationId = "rbxassetid://88455436394577" -- Replace with your running animation ID

local IdleAnimation = Instance.new("Animation")
IdleAnimation.AnimationId = "rbxassetid://507766388" -- Replace with your idle animation ID

local RunTrack = Animator:LoadAnimation(RunAnimation)
local IdleTrack = Animator:LoadAnimation(IdleAnimation)

-- State Variables
local IsRunning = false
local CurrentSpeed = BaseSpeed
local TargetFOV = BaseFOV

-- Function to adjust the FOV smoothly
local function AdjustFOV(targetFOV, duration)
	local tween = TweenService:Create(Camera, TweenInfo.new(duration, Enum.EasingStyle.Sine, Enum.EasingDirection.Out), {FieldOfView = targetFOV})
	tween:Play()
end

-- Running logic (accelerates while movement exists)
local function StartRunning()
	if IsRunning then return end -- Prevent re-entering running state
	IsRunning = true

	-- Stop idle animation if playing (with fade-out)
	if IdleTrack.IsPlaying then
		IdleTrack:Stop(0.5)
	end

	-- Start running animation
	RunTrack:Play()

	while IsRunning do
		if Humanoid.MoveDirection.Magnitude > 0 then
			-- Gradually increase speed
			CurrentSpeed = math.min(CurrentSpeed + AccelerationRate, MaxSpeed)
			Humanoid.WalkSpeed = CurrentSpeed

			-- Adjust FOV based on speed
			local speedRatio = (CurrentSpeed - BaseSpeed) / (MaxSpeed - BaseSpeed)
			TargetFOV = BaseFOV + (MaxFOV - BaseFOV) * speedRatio
			AdjustFOV(TargetFOV, 0.1)

			-- Increase animation speed in proportion to movement speed
			local adjustedSpeed = (CurrentSpeed / BaseSpeed) * AnimationSpeedMultiplier
			RunTrack:AdjustSpeed(adjustedSpeed)
		else
			break
		end
		task.wait(0.1)
	end

	-- If movement stopped, begin deceleration
	if IsRunning then
		StopRunning()
	end
end

-- StopRunning logic (gradually decelerates movement and transitions to idle)
local function StopRunning()
	if not IsRunning then return end
	IsRunning = false

	-- Gradually decelerate speed down to BaseSpeed
	while CurrentSpeed > BaseSpeed do
		CurrentSpeed = math.max(CurrentSpeed - DecelerationRate, BaseSpeed)
		Humanoid.WalkSpeed = CurrentSpeed

		local speedRatio = (CurrentSpeed - BaseSpeed) / (MaxSpeed - BaseSpeed)
		TargetFOV = BaseFOV + (MaxFOV - BaseFOV) * speedRatio
		AdjustFOV(TargetFOV, 0.1)

		-- Adjust animation speed to match deceleration
		local adjustedSpeed = (CurrentSpeed / BaseSpeed) * AnimationSpeedMultiplier
		RunTrack:AdjustSpeed(adjustedSpeed)
		task.wait(0.1)
	end

	-- Smooth transition to idle animation over 0.2 seconds
	RunTrack:AdjustWeight(0, 0.2)  -- Fade out the run animation over 0.2 seconds
	IdleTrack:AdjustWeight(0, 0.2) -- Fade in the idle animation over 0.2 seconds

	-- Reset walk speed and FOV
	Humanoid.WalkSpeed = BaseSpeed
	AdjustFOV(BaseFOV, 0.5)
end

-- Monitor movement changes to start or stop running
Humanoid:GetPropertyChangedSignal("MoveDirection"):Connect(function()
	if Humanoid.MoveDirection.Magnitude > 0 then
		StartRunning()
	else
		StopRunning()
	end
end)

this script is pretty bad for what im trying to do, if it helps to understand, its similar to games like parkour reborns running mechanic

#2

If what you’re looking for is to make your character accelerate and decelerate smoothly, maybe you’d like ControllerManager:

It works alongside GroundController:

The GroundController has two properties that might be exactly what you need:

These can help you fine-tune how your character speeds up and slows down.

If you want to know how to integrate it into your game, these resources might help:

About Animations:

I think the LocalScript that handles animations when a character spawns already manages this. As in, the faster you move, the faster the animation plays.

You could check the script that handles animation speed based on the Humanoid’s movement speed and extract the fragment that controls it. That way, you can tweak it or apply it in a way that better fits your setup.

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