# On Alpha Change

## Overview

![The On Alpha Change Node.](https://2628349686-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fwnv17cpjDin2deSlOz0z%2Fuploads%2Fgit-blob-14c2fce0d3c28bb21f985dc0239a8cb0f0b50350%2Fonalphachangeupdatedimage.png?alt=media)

**On Alpha Change** is an **Event Listener** **Node** used for executing a **Logic Branch** when the **Alpha** value of an **Object** changes.

[**Scope**](https://docs.incari.com/incari-studio/2023.1/overview#scopes): **Scene**, **Prefab**.

## Attributes

![The On Alpha Change Node Attributes.](https://2628349686-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fwnv17cpjDin2deSlOz0z%2Fuploads%2Fgit-blob-337da203149fa5e94f62ed7e123985865494a8f8%2Fonalphachangeattributes.png?alt=media)

| Attribute | Type         | Description                                                                                                                                  |
| --------- | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------- |
| `Object`  | **ObjectID** | The **Object** in which a change of the **Alpha** value triggers the **Logic Branch**, if none is given in the `Object ID` **Input Socket**. |

## Inputs

| Input           | Type         | Description                                                                            |
| --------------- | ------------ | -------------------------------------------------------------------------------------- |
| `Object ID`     | **ObjectID** | The **Object** in which a change of the **Alpha** value triggers the **Logic Branch**. |
| `Subscribe` (►) | **Pulse**    | An **Input Pulse** that needs to be triggered to start listening to the **Event**.     |

## Outputs

| Output             | Type         | Description                                                                                                                            |
| ------------------ | ------------ | -------------------------------------------------------------------------------------------------------------------------------------- |
| *Pulse Output* (►) | **Pulse**    | A standard **Output Pulse**, to move onto the next **Node** along the **Logic Branch**, once this **Node** has finished its execution. |
| `Alpha`            | **Float**    | The modified **Alpha** value.                                                                                                          |
| `Object ID`        | **ObjectID** | The **Object** received as **Input**.                                                                                                  |

## See Also

* [**Events**](https://docs.incari.com/incari-studio/2023.1/toolbox/events)
* [**Object**](https://docs.incari.com/incari-studio/2023.1/toolbox/events/object)
* [**Alpha**](https://docs.incari.com/incari-studio/2023.1/objects-and-types/attributes/common-attributes/sprite#alpha)