Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.
LineForce
Inherits from: Constraint → Instance → Object
The LineForce constraint applies a force along the theoretical line connecting its two Attachments. As the end points (attachments) move, the direction of force will change accordingly.
When configuring this constraint, it may be helpful to study Roblox Units to understand how Roblox units compare to metric units.
Force Location
By default, force is applied to either parent at its attachment location. If desired, force can be focused at each parent's center of mass by enabling ApplyAtCenterOfMass.
Inverse Square Law
When InverseSquareLaw is true, the force magnitude is multiplied by the inverse square of the distance, meaning the force will increase exponentially as the two attachments get closer together, like magnets. When using this setting, it's recommended that you set a MaxForce threshold to prevent infinite force if the attachments align precisely.
Reactionary Force
By default, the constraint only applies force to Attachment0, while Attachment1 remains unaffected. However, force can be applied to both attachments in equal and opposite directions by enabling ReactionForceEnabled.
Inherits from: Constraint
Memory category: BaseParts
Properties
| Name | Type / Returns | Description |
|---|---|---|
| LineForce.ApplyAtCenterOfMass | boolean | Whether force is applied at the center of mass of the parent assembly. |
| LineForce.InverseSquareLaw | boolean | When true, the force magnitude is multiplied by the inverse square of the distance. |
| LineForce.Magnitude | float | The magnitude of the force. |
| LineForce.MaxForce | float | Maximum absolute force that can be applied. |
| LineForce.ReactionForceEnabled | boolean | Enables an equal and opposite reaction force on the parent of Attachment1. |
Inherited from Constraint
| Name | Type / Returns | Description |
|---|---|---|
| Constraint.Active | boolean | Indicates if the constraint is currently active in the world. |
| Constraint.Attachment0 | Attachment | The Attachment that is connected to Constraint.Attachment1. |
| Constraint.Attachment1 | Attachment | The Attachment that is connected to Constraint.Attachment0. |
| Constraint.Color | BrickColor | The color of the constraint. |
| Constraint.Enabled | boolean | Toggles whether or not the constraint is enabled. |
| Constraint.Visible | boolean | Toggles the constraint's visibility. |
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance.Archivable | boolean | Determines if an Instance and its descendants can be cloned using Instance:Clone(), and can be saved/published. |
| Instance.archivable | boolean | |
| Instance.Capabilities | SecurityCapabilities | The set of capabilities allowed to be used for scripts inside this container. |
| Instance.IsInSandbox | boolean | Indicates whether the instance is inside a sandboxed container. |
| Instance.Name | string | A non-unique identifier of the Instance. |
| Instance.Parent | Instance | Determines the hierarchical parent of the Instance. |
| Instance.PredictionMode | PredictionMode | Reflects the client-side prediction mode applied to the instance under server-authoritative physics. |
| Instance.RobloxLocked | boolean | A deprecated property that used to protect CoreGui objects. |
| Instance.Sandboxed | boolean | When enabled, the instance can only access abilities in its Capabilities list. |
| Instance.UniqueId | UniqueId | A unique identifier for the instance. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object.ClassName | string | A read-only string representing the class this Object belongs to. |
| Object.className | string |
LineForce.ApplyAtCenterOfMass
When true, force is applied at the center of mass of the parent assembly of Attachment0, and the line determining the direction of the force will start at the said center of mass. When false, force is applied at Attachment0 and the line determining the direction will also start at Attachment0.
| Field | Value |
|---|---|
| type | boolean |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | LineForce |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["Physics"] |
| simulationAccess | true |
LineForce.InverseSquareLaw
When true, the force magnitude is multiplied by the inverse square of the distance.
| Field | Value |
|---|---|
| type | boolean |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | LineForce |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["Physics"] |
| simulationAccess | true |
LineForce.Magnitude
The magnitude of the force.
| Field | Value |
|---|---|
| type | float |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | LineForce |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["Physics"] |
| simulationAccess | true |
LineForce.MaxForce
The maximum absolute force that can be applied. This property is enabled only when InverseSquareLaw is also enabled. This property is mainly used to address the issue that the force of the body mover becomes infinite the closer the two attachments are, causing explosions that can't be prevented by scripts. This property bounds the force's absolute value.
| Field | Value |
|---|---|
| type | float |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | LineForce |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["Physics"] |
| simulationAccess | true |
LineForce.ReactionForceEnabled
Enables a reaction force (equal an opposite) to be applied to the parent of Attachment1. By default line force only applies a force on the parent of Attachment0 and uses Attachment1 as the target direction without any dynamic relationship.
| Field | Value |
|---|---|
| type | boolean |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | LineForce |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["Physics"] |
| simulationAccess | true |
Methods
Inherited from Constraint
| Name | Type / Returns | Description |
|---|---|---|
| Constraint:GetDebugAppliedForce | Vector3 | |
| Constraint:GetDebugAppliedTorque | Vector3 |
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance:AddTag | () | Applies a tag to the instance. |
| Instance:children | Instances | Returns an array of the object's children. |
| Instance:ClearAllChildren | () | This method destroys all of an instance's children. |
| Instance:Clone | Instance | Create a copy of an instance and all its descendants, ignoring instances that are not Archivable. |
| Instance:clone | Instance | |
| Instance:Destroy | () | Sets the Instance.Parent property to nil, locks the Instance.Parent property, disconnects all connections, and calls Destroy() on all children. |
| Instance:destroy | () | |
| Instance:FindFirstAncestor | Instance? | Returns the first ancestor of the Instance whose Instance.Name is equal to the given name. |
| Instance:FindFirstAncestorOfClass | Instance? | Returns the first ancestor of the Instance whose Object.ClassName is equal to the given className. |
| Instance:FindFirstAncestorWhichIsA | Instance? | Returns the first ancestor of the Instance for whom Object:IsA() returns true for the given className. |
| Instance:FindFirstChild | Instance? | Returns the first child of the Instance found with the given name. |
| Instance:findFirstChild | Instance | |
| Instance:FindFirstChildOfClass | Instance? | Returns the first child of the Instance whose ClassName is equal to the given class name. |
| Instance:FindFirstChildWhichIsA | Instance? | Returns the first child of the Instance for whom Object:IsA() returns true for the given className. |
| Instance:FindFirstDescendant | Instance? | Returns the first descendant found with the given Instance.Name. |
| Instance:GetActor | Actor? | Returns the Actor associated with the Instance, if any. |
| Instance:GetAttribute | Variant | Returns the value which has been assigned to the given attribute name. |
| Instance:GetAttributeChangedSignal | RBXScriptSignal | Returns an event that fires when the given attribute changes. |
| Instance:GetAttributes | Dictionary | Returns a dictionary of the instance's attributes. |
| Instance:GetChildren | Instances | Returns an array containing all of the instance's children. |
| Instance:getChildren | Instances | |
| Instance:GetDebugId | string | Returns a coded string of the debug ID used internally by Roblox. |
| Instance:GetDescendants | Instances | Returns an array containing all of the descendants of the instance. |
| Instance:GetFullName | string | Returns a string describing the instance's ancestry. |
| Instance:GetStyled | Variant | Returns the styled or explicitly modified value of the specified property, or else the default property value if it hasn't been styled/modified. |
| Instance:GetStyledPropertyChangedSignal | RBXScriptSignal | Returns an event that fires when the given style property changes on the instance. |
| Instance:GetTags | Array | Gets an array of all tags applied to the instance. |
| Instance:HasTag | boolean | Check whether the instance has a given tag. |
| Instance:IsAncestorOf | boolean | Returns true if an Instance is an ancestor of the given descendant. |
| Instance:IsDescendantOf | boolean | Returns true if an Instance is a descendant of the given ancestor. |
| Instance:isDescendantOf | boolean | |
| Instance:IsPropertyModified | boolean | Returns true if the value stored in the specified property is not equal to the code-instantiated default. |
| Instance:QueryDescendants | Instances | Returns an array containing all descendants of the instance that match the selector string. |
| Instance:Remove | () | Sets the object's Parent to nil, and does the same for all its descendants. |
| Instance:remove | () | |
| Instance:RemoveTag | () | Removes a tag from the instance. |
| Instance:ResetPropertyToDefault | () | Resets a property to its default value. |
| Instance:SetAttribute | () | Sets the attribute with the given name to the given value. |
| Instance:WaitForChild | Instance | Returns the child of the Instance with the given name. If the child does not exist, it will yield the current thread until it does. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object:GetPropertyChangedSignal | RBXScriptSignal | Get an event that fires when a given property of the object changes. |
| Object:IsA | boolean | Returns true if an object's class matches or inherits from a given class. |
| Object:isA | boolean |
Events
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance.AncestryChanged | Fires when the Instance.Parent property of this object or one of its ancestors is changed. | |
| Instance.AttributeChanged | Fires whenever an attribute is changed on the Instance. | |
| Instance.ChildAdded | Fires after an object is parented to this Instance. | |
| Instance.childAdded | ||
| Instance.ChildRemoved | Fires after a child is removed from this Instance. | |
| Instance.DescendantAdded | Fires after a descendant is added to the Instance. | |
| Instance.DescendantRemoving | Fires immediately before a descendant of the Instance is removed. | |
| Instance.Destroying | Fires immediately before (or is deferred until after) the instance is destroyed via Instance:Destroy(). | |
| Instance.StyledPropertiesChanged | Fires whenever any style property is changed on the instance, including when a property is set to nil. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object.Changed | Fires immediately after a property of the object changes, with some limitations. |