---
name: NumberSequenceKeypoint
last_updated: 2026-06-11T17:05:17Z
type: datatype
summary: "Represents keypoint within a NumberSequence with a particular time, value, and envelope size."
---

# NumberSequenceKeypoint

Represents keypoint within a [NumberSequence](/docs/reference/engine/datatypes/NumberSequence.md) with a particular time,
value, and envelope size.

**Type:** datatype

## Description

The [NumberSequenceKeypoint](/docs/reference/engine/datatypes/NumberSequenceKeypoint.md) data type represents keypoints within a
NumberSequence with a particular time, value, and envelope size.

## Constructors

### NumberSequenceKeypoint.new

**Signature:** `NumberSequenceKeypoint.new(time: number, value: number)`

Returns a keypoint with a specified time and value.

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `time` | `number` |  |  |
| `value` | `number` |  |  |

### NumberSequenceKeypoint.new

**Signature:** `NumberSequenceKeypoint.new(time: number, value: number, envelope: number)`

Returns a keypoint with a specified time, value, and envelope.

**Parameters:**

| Name | Type | Default | Description |
|------|------|---------|-------------|
| `time` | `number` |  |  |
| `value` | `number` |  |  |
| `envelope` | `number` |  |  |

## Properties

### NumberSequenceKeypoint.Envelope

**Type:** `number`

The amount of variance allowed from the value. For example, a value of 0.5
with an envelope of 0.1 could compute to between 0.4 and 0.6 at runtime.
The most common use case for this property is to randomize the size of
particles (within the envelope) from a
[ParticleEmitter](/docs/reference/engine/classes/ParticleEmitter.md).

### NumberSequenceKeypoint.Time

**Type:** `number`

The relative time at which the keypoint is positioned.

### NumberSequenceKeypoint.Value

**Type:** `number`

The base value of this keypoint.