🚀 Mastering Roblox LinearVelocity: The Secret Force Behind Smooth Physics (Formerly BodyVelocity)

“Why does my part slide weirdly when I use Velocity? Why does it feel jittery? What’s the modern way to push characters and objects in Roblox physics?”

If you’ve ever asked yourself those questions, you’re not alone. Every Roblox developer eventually hits this wall. You want a boulder to roll convincingly, a projectile to fly straight, or your character to dash like lightning… but you’re stuck wrestling with old, deprecated objects like BodyVelocity.

Enter LinearVelocity – Roblox’s modern, powerful, and intuitive solution for applying directional force and smooth movement in your games. If you’ve been confused, frustrated, or overwhelmed by physics objects before, this article will give you clarity, confidence, and concrete examples.

By the end, you’ll know exactly:

• ✅ What LinearVelocity is and why it replaced BodyVelocity

• ✅ How to set it up and control it in just a few lines of code

• ✅ Real-world use cases (dashes, knockbacks, vehicles, projectiles, flying parts, and more)

• ✅ The developer questions everyone secretly asks… finally answered

Ready? Let’s dive in.

🎯 The Hook: Why LinearVelocity Changed Everything

Once upon a time, Roblox gave us BodyVelocity. It worked… kinda. But it was clunky, outdated, and didn’t play nicely with modern physics. Developers complained:

• “My parts jitter when colliding.”

• “Characters get flung to the moon.”

• “How do I control when the force applies?”

Roblox listened. Enter Attachment-based forces – a new family of constraints designed to be more realistic, stable, and customizable. That’s where LinearVelocity comes in. Think of it as the BodyVelocity 2.0 — but smarter, cleaner, and future-proof.

🧩 What Is LinearVelocity, Really?

LinearVelocity is a constraint object that applies velocity to whatever part it’s attached to. Instead of constantly setting .Velocity on a part (which fights with Roblox’s physics engine), LinearVelocity tells Roblox:

“Hey engine, this object should be moving at this speed, in this direction, until I say otherwise.”

That’s it. The engine handles the rest.

The key difference? LinearVelocity uses Attachments to define where and how the force applies. This makes it incredibly flexible and predictable.

⚡ How To Use LinearVelocity (Step-by-Step)

Let’s say you want to push a part forward like a projectile. Here’s the simple recipe:

Step 1 – Insert an Attachment

Every LinearVelocity needs an attachment point.

local part = script.Parent
local attachment = Instance.new("Attachment")
attachment.Parent = part

Step 2 – Create the LinearVelocity

local lv = Instance.new("LinearVelocity")
lv.Parent = part
lv.Attachment0 = attachment

Step 3 – Configure Velocity

lv.VectorVelocity = Vector3.new(0, 0, -100) -- forward push
lv.MaxForce = math.huge -- how strong the push is

Done. That’s it. The part now rockets forward smoothly.

🛠️ Use Cases That Make Developers Say “Ah, Finally!”

1. Player Dashes

Want your character to zoom forward like an anime hero? Add a LinearVelocity to their HumanoidRootPart with a short burst of force.

local player = game.Players.LocalPlayer
local char = player.Character or player.CharacterAdded:Wait()
local hrp = char:WaitForChild("HumanoidRootPart")

local attachment = Instance.new("Attachment", hrp)
local dash = Instance.new("LinearVelocity", hrp)
dash.Attachment0 = attachment
dash.VectorVelocity = hrp.CFrame.LookVector * 60
dash.MaxForce = 2000

game:GetService("Debris"):AddItem(dash, 0.3) -- remove after dash

This creates a clean, powerful dash mechanic without fighting Roblox physics.

2. Knockbacks & Explosions

When a player gets hit by an attack, you want them to fly backward, but not break physics. LinearVelocity makes this easy:

local direction = (target.Position - explosion.Position).Unit
knockback.VectorVelocity = direction * 80

Smooth knockback, predictable control.

3. Vehicles

Cars, spaceships, hoverboards — all can use LinearVelocity to apply movement in a stable way. Combine it with AngularVelocity for turning and you’ve got the start of a solid vehicle system.

4. Flying Parts / Boulder Systems

Throwing boulders? Dropping crates? Flinging bombs? With LinearVelocity, you can launch objects that behave naturally — no more glitchy jitter.

❓ Developer Questions Answered

Here are the big ones that haunt Roblox devs:

Q1: Why not just set .Velocity directly?

Because Roblox’s physics engine constantly recalculates forces. Setting .Velocity fights the engine, causing jitter. LinearVelocity cooperates with physics — smooth and realistic.

Q2: What’s the difference between LinearVelocity and BodyVelocity?

• BodyVelocity: Deprecated, global force, often unstable.

• LinearVelocity: Attachment-based, scoped, precise, and modern.

Think: BodyVelocity = hammer, LinearVelocity = scalpel.

Q3: Do I need MaxForce?

Yes! Without it, your object won’t move. MaxForce is the limit of how strong LinearVelocity can push. Set it to math.huge if you just want it to always work.

Q4: How do I stop it?

Destroy the LinearVelocity or set VectorVelocity = Vector3.zero. Easy.

Q5: Can I combine it with other forces?

Absolutely. LinearVelocity works beautifully with AngularVelocity, VectorForce, and constraints like AlignOrientation. Together, you can craft some of the smoothest mechanics Roblox physics allows.

🧪 Pro Tips For Developers

• Short bursts, not forever: For dashes, knockbacks, or projectiles, wrap LinearVelocity in Debris:AddItem so it cleans itself up.

• Use Attachments creatively: You can place attachments anywhere (e.g., weapon tip, player’s back) to control exactly where the force applies.

• Debug visually: Attachments are tiny yellow indicators in Studio — use them to confirm positioning.

• Tween velocity changes: Instead of instantly applying full force, Tween VectorVelocity for smooth acceleration.

🔥 Copy-Paste Example: Dash System

Here’s a ready-to-go dash script you can drop into a LocalScript:

Press Q → Player dashes forward. Done. Clean, efficient, powerful.

🌟 Why This Matters For You

The truth is, LinearVelocity is the building block for modern Roblox movement systems. Whether you’re making an anime battler, a simulator, or a physics sandbox, you’ll eventually need smooth, controllable movement.

And the best part? Once you understand LinearVelocity, every other physics constraint starts to click. You’ll unlock better vehicles, cleaner knockbacks, polished dashes, and fewer bugs.

🎬 Final Takeaway | Roblox LinearVelocity

LinearVelocity isn’t just “BodyVelocity’s replacement.” It’s Roblox’s gift to developers who want control + realism + simplicity.

So next time you need movement:

• Don’t hack velocity values.

• Don’t revive old BodyMovers.

• Use LinearVelocity — the clean, modern way.

And remember: great movement feels invisible to players but unforgettable in gameplay.

Go build that dash. Launch that boulder. Craft that vehicle. With LinearVelocity, you’re not fighting Roblox physics anymore — you’re working with it.