---
name: RotationCurve
last_updated: 2026-06-10T23:09:12Z
inherits:
  - Instance
  - Object
type: class
memory_category: Instances
summary: "Represents a sequence of rotations and the interpolation curve between them."
---

# Class: RotationCurve

> Represents a sequence of rotations and the interpolation curve between them.

## Description

This class holds a sorted list of
[RotationCurveKeys](/docs/reference/engine/datatypes/RotationCurveKey.md) that represent a sequence of
rotations. The shape of the interpolation curve between two keys is determined
by the [RotationCurveKey.Interpolation](/docs/reference/engine/datatypes/RotationCurveKey.md) type.

## Properties

### Property: RotationCurve.Length

```json
{
  "type": "int",
  "access": "ReadWrite",
  "security": {
    "read": "None",
    "write": "None"
  },
  "serialization": {
    "can_load": false,
    "can_save": true
  },
  "thread_safety": "ReadSafe",
  "category": "Data",
  "capabilities": [
    "Basic"
  ]
}
```

Number of rotation keys in this curve.

## Methods

### Method: RotationCurve:GetKeyAtIndex

**Signature:** `RotationCurve:GetKeyAtIndex(index: int): RotationCurveKey`

Returns a copy of a key at a given index.

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `index` | `int` |  |  |

**Returns:** `RotationCurveKey`

### Method: RotationCurve:GetKeyIndicesAtTime

**Signature:** `RotationCurve:GetKeyIndicesAtTime(time: float): Array`

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).

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `time` | `float` |  |  |

**Returns:** `Array`

### Method: RotationCurve:GetKeys

**Signature:** `RotationCurve:GetKeys(): Array`

Returns a copy of all the keys in the rotation curve as a Luau array of
[RotationCurveKeys](/docs/reference/engine/datatypes/RotationCurveKey.md).

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Returns:** `Array` — Array of [RotationCurveKeys](/docs/reference/engine/datatypes/RotationCurveKey.md).

### Method: RotationCurve:GetValueAtTime

**Signature:** `RotationCurve:GetValueAtTime(time: float): CFrame?`

Samples the rotation curve at a given time and returns the corresponding
rotation as a [CFrame](/docs/reference/engine/datatypes/CFrame.md). Empty rotation curves are evaluated as
[CFrame.identity](/docs/reference/engine/datatypes/CFrame.md).

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `time` | `float` |  | Time at which to sample the curve. |

**Returns:** `CFrame?` — Value of the curve at the requested `time`.

### Method: RotationCurve:InsertKey

**Signature:** `RotationCurve:InsertKey(key: RotationCurveKey): Array`

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.

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `key` | `RotationCurveKey` |  | [RotationCurveKey](/docs/reference/engine/datatypes/RotationCurveKey.md) to insert. |

**Returns:** `Array` — (see description) .

### Method: RotationCurve:RemoveKeyAtIndex

**Signature:** `RotationCurve:RemoveKeyAtIndex(startingIndex: int, count?: int): int`

Removes a given number (`count`) of keys starting from the `startingIndex`
index and returns the number of keys that were removed.

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `startingIndex` | `int` |  | Starting index from which to remove keys. |
| `count` | `int` | `1` | Number of keys to remove. |

**Returns:** `int` — Number of keys removed.

### Method: RotationCurve:SetKeys

**Signature:** `RotationCurve:SetKeys(keys: Array): int`

Resets this curve's keys using the [RotationCurveKey](/docs/reference/engine/datatypes/RotationCurveKey.md) 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.

*Security: None · Thread Safety: Unsafe · Capabilities: Basic*

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `keys` | `Array` |  | Array of [RotationCurveKeys](/docs/reference/engine/datatypes/RotationCurveKey.md). |

**Returns:** `int` — Number of keys inserted.

## Inherited Members

### From [Instance](/docs/reference/engine/classes/Instance.md)

- **Property `Archivable`** (`boolean`): Determines if an Instance and its descendants can be cloned using
- **Property `archivable`** (`boolean`):  *(deprecated, hidden)*
- **Property `Capabilities`** (`SecurityCapabilities`): The set of capabilities allowed to be used for scripts inside this
- **Property `Name`** (`string`): A non-unique identifier of the Instance.
- **Property `Parent`** (`Instance`): Determines the hierarchical parent of the Instance.
- **Property `PredictionMode`** (`PredictionMode`): 
- **Property `RobloxLocked`** (`boolean`): A deprecated property that used to protect CoreGui objects. *(hidden)*
- **Property `Sandboxed`** (`boolean`): When enabled, the instance can only access abilities in its `Capabilities`
- **Property `UniqueId`** (`UniqueId`): A unique identifier for the instance.
- **Method `AddTag(tag: string): ()`**: Applies a tag to the instance.
- **Method `children(): Instances`**: Returns an array of the object's children. *(deprecated)*
- **Method `ClearAllChildren(): ()`**: This method destroys all of an instance's children.
- **Method `Clone(): Instance`**: Create a copy of an instance and all its descendants, ignoring instances
- **Method `clone(): Instance`**:  *(deprecated)*
- **Method `Destroy(): ()`**: Sets the Instance.Parent property to `nil`, locks the
- **Method `destroy(): ()`**:  *(deprecated)*
- **Method `FindFirstAncestor(name: string): Instance?`**: Returns the first ancestor of the Instance whose
- **Method `FindFirstAncestorOfClass(className: string): Instance?`**: Returns the first ancestor of the Instance whose
- **Method `FindFirstAncestorWhichIsA(className: string): Instance?`**: Returns the first ancestor of the Instance for whom
- **Method `FindFirstChild(name: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance found with the given name.
- **Method `findFirstChild(name: string, recursive?: boolean): Instance`**:  *(deprecated)*
- **Method `FindFirstChildOfClass(className: string): Instance?`**: Returns the first child of the Instance whose
- **Method `FindFirstChildWhichIsA(className: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance for whom
- **Method `FindFirstDescendant(name: string): Instance?`**: Returns the first descendant found with the given Instance.Name.
- **Method `GetActor(): Actor?`**: Returns the Actor associated with the Instance, if any.
- **Method `GetAttribute(attribute: string): Variant`**: Returns the value which has been assigned to the given attribute name.
- **Method `GetAttributeChangedSignal(attribute: string): RBXScriptSignal`**: Returns an event that fires when the given attribute changes.
- **Method `GetAttributes(): Dictionary`**: Returns a dictionary of the instance's attributes.
- **Method `GetChildren(): Instances`**: Returns an array containing all of the instance's children.
- **Method `getChildren(): Instances`**:  *(deprecated)*
- **Method `GetDebugId(scopeLength?: int): string`**: Returns a coded string of the debug ID used internally by Roblox.
- **Method `GetDescendants(): Instances`**: Returns an array containing all of the descendants of the instance.
- **Method `GetFullName(): string`**: Returns a string describing the instance's ancestry.
- **Method `GetStyled(name: string, selector: string?): Variant`**: Returns the styled or explicitly modified value of the specified property,
- **Method `GetStyledPropertyChangedSignal(property: string): RBXScriptSignal`**: 
- **Method `GetTags(): Array`**: Gets an array of all tags applied to the instance.
- **Method `HasTag(tag: string): boolean`**: Check whether the instance has a given tag.
- **Method `IsAncestorOf(descendant: Instance): boolean`**: Returns true if an Instance is an ancestor of the given
- **Method `IsDescendantOf(ancestor: Instance): boolean`**: Returns `true` if an Instance is a descendant of the given
- **Method `isDescendantOf(ancestor: Instance): boolean`**:  *(deprecated)*
- **Method `IsPropertyModified(property: string): boolean`**: Returns `true` if the value stored in the specified property is not equal
- **Method `QueryDescendants(selector: string): Instances`**: 
- **Method `Remove(): ()`**: Sets the object's `Parent` to `nil`, and does the same for all its *(deprecated)*
- **Method `remove(): ()`**:  *(deprecated)*
- **Method `RemoveTag(tag: string): ()`**: Removes a tag from the instance.
- **Method `ResetPropertyToDefault(property: string): ()`**: Resets a property to its default value.
- **Method `SetAttribute(attribute: string, value: Variant): ()`**: Sets the attribute with the given name to the given value.
- **Method `WaitForChild(childName: string, timeOut: double): Instance`**: Returns the child of the Instance with the given name. If the
- **Event `AncestryChanged`**: Fires when the Instance.Parent property of this object or one of
- **Event `AttributeChanged`**: Fires whenever an attribute is changed on the Instance.
- **Event `ChildAdded`**: Fires after an object is parented to this Instance.
- **Event `childAdded`**:  *(deprecated)*
- **Event `ChildRemoved`**: Fires after a child is removed from this Instance.
- **Event `DescendantAdded`**: Fires after a descendant is added to the Instance.
- **Event `DescendantRemoving`**: Fires immediately before a descendant of the Instance is removed.
- **Event `Destroying`**: Fires immediately before (or is deferred until after) the instance is
- **Event `StyledPropertiesChanged`**: Fires whenever any style property is changed on the instance, including

### From [Object](/docs/reference/engine/classes/Object.md)

- **Property `ClassName`** (`string`): A read-only string representing the class this Object belongs to.
- **Property `className`** (`string`):  *(deprecated)*
- **Method `GetPropertyChangedSignal(property: string): RBXScriptSignal`**: Get an event that fires when a given property of the object changes.
- **Method `IsA(className: string): boolean`**: Returns true if an object's class matches or inherits from a given class.
- **Method `isA(className: string): boolean`**:  *(deprecated)*
- **Event `Changed`**: Fires immediately after a property of the object changes, with some