If you've ever wanted to build a Mario Galaxy-style world, you definitely need a solid roblox planet gravity script sphere to get things moving. Standard Roblox physics are great for flat ground, but the moment you try to walk around a big ball in space, everything falls apart. You end up sliding off the side or falling into the void because the engine assumes "down" is always the same direction. To fix this, we have to take control of the physics engine and tell it exactly where "down" should be.
Why default gravity won't cut it
Let's be honest, the default gravity in Roblox is a bit of a one-trick pony. It pulls everything toward the bottom of the Y-axis. That works perfectly for a city builder or a typical obby, but it's a total nightmare if you're trying to make a space exploration game. If you place a large sphere in your workspace and try to walk on it, your character will stay upright relative to the world, not the sphere. Once you walk past the "equator," you just slip off.
To create a working roblox planet gravity script sphere, we have to essentially turn off the global gravity for the player and replace it with a custom force that pulls them toward the center of the planet. It sounds complicated, but once you break down the math into simple vectors, it starts to make a lot of sense.
Setting up your planet in Studio
Before we even touch a script, we need something to walk on. Open up Roblox Studio and pop a Part into the workspace. Change its shape to a ball and scale it up—make it huge, like 100x100x100, so you have plenty of room to run around. Let's name this "Planet."
You'll also want to make sure the planet is anchored. If it isn't, your custom gravity might end up pulling the planet toward the player instead of the other way around, which is hilarious but not exactly what we're going for. Once your sphere is sitting there in the void, it's time to think about how we're going to manipulate the player's character.
The logic behind spherical gravity
The core idea of a roblox planet gravity script sphere relies on two main things: pulling the player toward the center and rotating the player so their feet always touch the surface.
First, the pull. We calculate a vector that starts at the player's position and points directly at the center of the sphere. By applying a constant force in that direction, we simulate gravity. The closer you are to the center, the stronger the direction is defined.
Second, the orientation. This is where most people get stuck. If you just pull the player down, they'll stay standing straight up (relative to the sky) while their feet drag along the side of the ball. We need to use some CFrame magic to rotate the player's RootPart so that their "up" vector matches the surface normal of the sphere.
Writing the basic gravity script
You generally want to handle this on the client side using a LocalScript inside StarterCharacterScripts. Why? Because it makes the movement feel much smoother. If the server handles the gravity, there's going to be a tiny bit of lag, and your character will look jittery as they try to stick to the planet.
In your script, you'll want to use RunService.Heartbeat. This runs every single frame after the physics have been calculated. Inside that loop, you'll find the distance between the player and the center of the planet.
```lua -- A quick look at the logic local player = game.Players.LocalPlayer local char = player.Character or player.CharacterAdded:Wait() local root = char:WaitForChild("HumanoidRootPart") local planet = workspace:WaitForChild("Planet")
game:GetService("RunService").Heartbeat:Connect(function() local direction = (planet.Position - root.Position).Unit -- This direction is our new 'down' end) ```
By taking the planet's position and subtracting the player's position, we get a vector. By calling .Unit on it, we turn it into a direction with a length of one. This is the foundation of your roblox planet gravity script sphere.
Keeping the player upright
Now that we know which way is down, we have to make sure the player isn't walking on their head. We do this by adjusting the CFrame of the HumanoidRootPart. We want to construct a new CFrame where the "up" vector is the opposite of our gravity direction.
Roblox has a handy way of doing this with CFrame.fromMatrix. You define the position, the right vector, and the up vector, and the engine fills in the rest. If you keep the player's "up" pointing away from the planet's center, they will naturally look like they are standing on a round surface.
One thing to watch out for: the Humanoid object likes to fight you. It really wants to stay upright relative to the world's Y-axis. You might need to set Humanoid.PlatformStand to true, or better yet, use a VectorForce and an AlignOrientation constraint. These newer physics constraints are way more stable than trying to manually set the CFrame every frame.
Making jumping feel natural
Jumping is usually the biggest hurdle when messing with a roblox planet gravity script sphere. When you press the jump button, the default Roblox jump force pushes the player "up" (toward the sky). On a sphere, "up" is constantly changing.
To fix this, you might need to disable the default jump and write a custom one. When the player hits the spacebar, you apply a quick impulse force in the direction of their own "up" vector. Since we've already aligned their Up vector to point away from the planet, the jump will feel perfectly natural, no matter where they are on the sphere.
Handling multiple planets
What if you want a whole galaxy? Having one roblox planet gravity script sphere is cool, but having five or six you can jump between is even better. To do this, your script needs to figure out which planet is the closest.
Inside your loop, you can iterate through a folder of planets and calculate the distance to each one. Whichever one is closest is the one that "claims" the player's gravity. You can even add a little "gravity well" effect where the pull gets stronger as you get closer to the surface, allowing for cool transitions where a player leaps from a small moon toward a larger planet.
Common pitfalls and how to avoid them
One common issue is "jittering." This usually happens when your script and the internal physics engine are fighting over the character's position. If you notice your character shaking, try lowering the force or using LinearVelocity constraints to handle the movement.
Another big one is the "camera freakout." The standard Roblox camera doesn't know you're walking sideways on a giant ball. It'll try to keep the horizon level, which will look very wrong very quickly. You'll likely need to script a custom camera that follows the player's local orientation rather than the global one. It's a bit of extra work, but it's the difference between a tech demo and a playable game.
Wrapping things up
Creating a roblox planet gravity script sphere is one of those projects that feels like a huge accomplishment once you get it working. It breaks the "flat world" mold that most Roblox games are stuck in and opens up a ton of creative possibilities. Whether you're making a space sim, a trippy puzzle game, or just a cool hangout spot, spherical gravity adds a layer of polish that really stands out.
It takes some trial and error, especially with the CFrame math and the physics constraints, but don't let that discourage you. Start small with one sphere and a simple pull force, then gradually add the rotation and the jumping logic. Before you know it, you'll have a fully functioning planetary system that feels just as good to play as any professional console game. Happy building!