Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.
FloatCurve
Inherits from: Instance → Object
An instance representing a 1D float curve encoded via a sorted list of FloatCurveKeys. The shape of the interpolation curve between two keys is determined by the FloatCurveKey.Interpolation type.
Inherits from: Instance
Memory category: Instances
Properties
| Name | Type / Returns | Description |
|---|---|---|
| FloatCurve.Length | int | Number of keys in the float curve. |
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 |
FloatCurve.Length
Number of keys in the float curve.
| Field | Value |
|---|---|
| type | int |
| tags | ["ReadOnly","NotReplicated"] |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Data |
| serialization | {"can_load":false,"can_save":true} |
| capabilities | ["Basic"] |
Methods
| Name | Type / Returns | Description |
|---|---|---|
| FloatCurve:GetKeyAtIndex | FloatCurveKey | Returns a copy of a key at a given index. |
| FloatCurve:GetKeyIndicesAtTime | Array | Returns the index of the last and first key of a period of time. |
| FloatCurve:GetKeys | Array | Returns a copy of all the keys in the FloatCurve as a Luau array of FloatCurveKeys. |
| FloatCurve:GetValueAtTime | float? | Samples the float curve at a given time passed as argument. |
| FloatCurve:InsertKey | Array | Adds the key passed as an argument to this curve. If a key at the same time is found, it will be replaced. |
| FloatCurve:RemoveKeyAtIndex | int | Removes a given number of keys starting from a given index. |
| FloatCurve:SetKeys | int | Resets this curve's keys using the FloatCurveKey array passed as an argument. |
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 |
FloatCurve:GetKeyAtIndex
Returns a copy of a key at a given index.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| index | int | One-based index of the key to retrieve. |
Returns
| Type | Description |
|---|---|
| FloatCurveKey | Copy of the FloatCurveKey stored at index. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:GetKeyIndicesAtTime
The first item in the returned array is the index of the last key with time less than or equal to time (or the lesser of either 1 or the curve length if no key was found). The second item in the returned array is the index of the first key with time greater than or equal to time (or the curve length if no key was found satisfying the inequality).
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| time | float | Time value to locate within the curve's sorted keys. |
Returns
| Type | Description |
|---|---|
| Array | Array of two one-based indices that bracket time: the last key at or before time and the first key at or after it. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:GetKeys
Returns a copy of all the keys in the FloatCurve as a Luau array of FloatCurveKeys.
Returns
| Type | Description |
|---|---|
| Array | Array of FloatCurveKeys. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:GetValueAtTime
Samples the float curve at a given time passed as argument.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| time | float | Time at which to sample the curve. |
Returns
| Type | Description |
|---|---|
| float? | Value of the curve at the requested time. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:InsertKey
Adds the key passed as an argument to this curve. If a key at the same time is found, it will be replaced. In the returned array, the first value is true if a key was added or false if a previous key was replaced; the second value is the index at which the marker was added.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| key | FloatCurveKey | FloatCurveKey to insert. |
Returns
| Type | Description |
|---|---|
| Array | (see description) . |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:RemoveKeyAtIndex
Removes a given number (count) of keys starting from the startingIndex index and returns the number of keys that were removed.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| startingIndex | int | Starting index from which to remove keys. | |
| count | int | 1 | Number of keys to remove. |
Returns
| Type | Description |
|---|---|
| int | Number of keys removed. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
FloatCurve:SetKeys
Resets this curve's keys using the FloatCurveKey array passed as an argument. Keys in the keys array are sorted in ascending time order before insertion, and keys at duplicated times are removed in a stable manner.
Returns the number of keys actually inserted. Keys previously stored in this curve are removed before the keys passed as arguments are added.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| keys | Array | Array of FloatCurveKeys. |
Returns
| Type | Description |
|---|---|
| int | Number of keys inserted. |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["Basic"] |
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. |