A roblox body position script is one of those fundamental tools that every developer eventually needs when they realize that simply changing a part's CFrame over and over again looks way too jittery. If you've ever tried to make a floating platform, a pet that follows a player, or even a simple elevator, you probably noticed that teleporting an object every frame feels "off." Using a script to handle body position allows the physics engine to take the wheel, creating smooth, realistic movement that actually interacts with the world around it.
It's worth noting right out of the gate that Roblox has technically "deprecated" the BodyPosition object in favor of newer constraints like LinearVelocity or AlignPosition. But let's be real: a lot of us still reach for the classic roblox body position script because it's incredibly intuitive and, frankly, it still works just fine for a huge variety of projects.
Getting the Basics Down
Before we jump into the code, you need to understand what's actually happening under the hood. When you put a BodyPosition object into a Part, you're basically telling that part, "I want you to try your hardest to get to this specific coordinate in the 3D world."
The script doesn't just teleport the part. Instead, it applies a force to push the part toward the target. If something is in the way, the part will bump into it. If the part is heavy, it might move slowly. This is why it's so much better than just setting Part.Position—it respects the laws of physics (well, Roblox physics, anyway).
Setting Up Your First Script
Let's look at a super basic example. Imagine you have a simple block in your workspace, and you want it to hover exactly ten studs above wherever it started. Here is how you'd set up a basic script to handle that.
```lua local part = script.Parent local bp = Instance.new("BodyPosition")
bp.Position = part.Position + Vector3.new(0, 10, 0) bp.MaxForce = Vector3.new(math.huge, math.huge, math.huge) bp.P = 10000 -- This is the 'Power' or aggressiveness bp.D = 500 -- This is the 'Damping' or the brakes
bp.Parent = part ```
In this little snippet, we're creating the object via code. The MaxForce part is usually where beginners get stuck. If you leave MaxForce at its default (which is often too low), your part might just sit on the floor because it doesn't have enough "strength" to lift its own weight. By setting it to math.huge, we're telling the script to use as much force as necessary to reach the goal.
The Secret Sauce: P and D Properties
If you want your roblox body position script to feel professional, you have to mess with the P and D properties. These sound like math homework, but they're actually pretty simple once you see them in action.
The P (Power/Proportional): Think of this as how "angry" the part is to get to its destination. A high P value means the part will launch itself toward the target position with a ton of speed. If it's too low, the part will feel sluggish, like it's moving through molasses.
The D (Damping): This is essentially the shock absorber. If you have a high P but a low D, the part will fly toward the target, overshoot it, fly back, overshoot it again, and basically wobble forever. By increasing the D value, you're telling the part to "slow down as you get close." It smooths out the arrival so the object settles into place nicely.
Finding the balance between these two is what separates a janky-looking game from a polished one. Usually, I start with a P of 10,000 and a D of 500, then tweak them until the movement feels right.
Making a Follower Pet
One of the coolest ways to use a roblox body position script is for a pet system. You don't want the pet to be glued to the player's side; you want it to hover near them, maybe bobbing up and down a little.
To do this, you'd run a loop (like a RunService.Heartbeat or a simple while true do loop) that constantly updates the BodyPosition.Position to a spot slightly behind the player's Character. Because the physics engine is handling the movement, the pet will naturally drift behind the player, slowing down when they stop and speeding up when they run. It gives the "AI" a sense of weight and life that you just can't get with static positioning.
Why use this over the newer stuff?
I mentioned earlier that Roblox suggests using AlignPosition now. You might be wondering, "Why should I bother with a roblox body position script if it's old news?"
The main reason is simplicity. AlignPosition requires two attachments—one on the object and one for the target. It's great for complex mechanical rigs, but for a single part you just want to move from A to B, it can feel like overkill. The old-school BodyPosition is a "drop-in" solution. You put it in the part, give it a Vector3, and it goes. For prototyping or simple gameplay elements, that speed is hard to beat.
However, keep in mind that if you're building something massive or a game you intend to support for the next ten years, learning the newer constraints is a smart move. But for learning the ropes? The classic script is a fantastic teacher.
Troubleshooting Common Issues
We've all been there: you write your script, hit play, and nothing happens. Or worse, the part flies into the stratosphere at Mach 5. If your roblox body position script isn't behaving, check these three things:
- Is the part Anchored? This is the #1 mistake. If a part is anchored, the physics engine ignores it.
BodyPosition(and all body movers) only work on unanchored parts. If you need it to stay still until the script runs, keep it anchored in the editor and then usepart.Anchored = falsein your script right before you create the BodyPosition. - Is the MaxForce high enough? If your part is huge or made of a dense material like Lead, the default force might not be enough to move it. Crank those
MaxForcevalues up tomath.hugeto see if that fixes it. - Are there conflicting forces? If you have a
BodyVelocityand aBodyPositionin the same part, they're going to fight each other. Make sure you aren't sending mixed signals to the physics engine.
Wrapping Up the Logic
At the end of the day, mastering the roblox body position script is about understanding the relationship between scripts and physics. You aren't just telling the game where things should be; you're telling the game how they should get there.
Experiment with different values. Try making a part that follows your mouse cursor, or a series of platforms that move in a patrol loop. The more you play with the P and D settings, the more you'll start to "feel" how Roblox handles motion. It's a small step in scripting, but it makes a massive difference in how your game feels to the players. Happy building!