UnityGame/Library/PackageCache/com.unity.inputsystem/Documentation~/PlayerInput.md

uid
input-system-player-input

The Player Input component

The Player Input component provides two related but separate features which can be useful in common game scenarios. These are:

• Configuring how Actions map to methods or callbacks in the script that controls your player.

• Handling local multiplayer scenarios such as player lobbies, device filtering, and screen-splitting.

The Player Input component

Above, the Player Input component displayed in the inspector.

Connecting actions to methods or callbacks

The Player Input component represents a single player, and the connection between that player's associated device, Actions, and methods or callbacks.

You can use a single instance of a Player Input component in a single-player game to set up a mapping between your Input Actions and methods or callbacks in the script that controls your player.

For example, by using the Player Input component, you can set up a mapping between actions such as "Jump" to C# methods in your script such as public void OnJump().

There are a few options for doing exactly how the Player Input component does this, such as using SendMessage, or Unity Events, which is described in more detail below.

Handling local multiplayer scenarios

You can also have multiple Player Input components active at the same time (each on a separate instance of a prefab) along with the Player Input Manager component to implement local multiplayer features, such as device filtering, and screen-splitting.

In these local multiplayer scenarios, the Player Input component should be on a prefab that represents a player in your game, which the Player Input Manager has a reference to. The Player Input Manager then instantiates players as they join the game and pairs each player instance to a unique device that the player uses exclusively (for example, one gamepad for each player). You can also manually pair devices in a way that enables two or more players to share a Device (for example, left/right keyboard splits or hot seat use).

Each PlayerInput corresponds to one InputUser. You can use PlayerInput.user to query the InputUser from the component.

Getting started

To get started using the Player Input component, use the following steps:

1. Add a Player Input component to a GameObject. This would usually be the GameObject that represents the player in your game.
2. Assign your Action Asset to the Actions field. This is usually the default project-wide action asset named "InputSystem_Actions"
3. Set up Action responses, by selecting a Behaviour type from the Behaviour menu. The Behaviour type you select affects how you should implement the methods that handle your Action responses. See the notification behaviors section further down for details.
   
   
   
   

Configuring the Player Input component

You can use the following properties to configure PlayerInput:

Property	Description
Actions	The set of Input Actions associated with the player. Typically you would set this to Project-Wide Actions, however you can assign an ActionAsset reference here). To receive input, each player must have an associated set of Actions. See documentation on Actions for details.
Default Control Scheme	Which Control Scheme (from what is defined in Actions) to enable by default.
Default Action Map	Which Action Map in Actions to enable by default. If set to None, then the player starts with no Actions being enabled.
Camera	The individual camera associated with the player. This is only required when employing split-screen setups and has no effect otherwise.
Behavior	How the PlayerInput component notifies game code about things that happen with the player. See documentation on notification behaviors.

Actions

To receive input, each player must have an associated set of Input Actions.

Specifying the Actions to use

The simplest workflow is to use the project-wide actions defined in the Input Actions editor. However, the Player Input component also allows you to use an Actions Asset to specify the actions that should be used by any instance of the component. If you set the Actions field to Actions Asset, the inspector displays a field into which you can assign an actions asset, and a Create Actions button which allows you to create a new actions asset. When you create these via the Player Input inspector's Create Actions button, the Input System creates a default set of Actions. However, the Player Input component places no restrictions on the arrangement of Actions.

Enabling and disabling Actions

The Player Input component automatically handles enabling and disabling Actions, and also handles installing callbacks on the Actions. When multiple Player Input components use the same Actions, the components automatically create private copies of the Actions. This is why, when writing input code that works with the PlayerInput component, you should not use InputSystem.actions because this references the "singleton" copy of the actions rather than the specific private copy associated with the PlayerInput instance you are coding for.

When first enabled, the Player Input component enables all Actions from the the Default Action Map. If no default Action Map exists, the Player Input component does not enable any Actions. To manually enable Actions, you can call Enable and Disable on the Action Maps or Actions, like you would do without PlayerInput. To check which Action Map is currently enabled, or to switch to a different one, use the PlayerInput.currentActionMap property. To switch Action Maps with an Action Map name, you can also call PlayerInput.SwitchCurrentActionMap.

To disable a player's input, call PlayerInput.DeactivateInput. To re-enable it, call PlayerInput.ActivateInput. The latter enables the default Action Map, if it exists.

When PlayerInput is disabled, it automatically disables the currently active Action Map (PlayerInput.currentActionMap) and disassociate any Devices paired to the player.

See the notification behaviors section below for how to be notified when player triggers an Action.

When using Send Messages or Broadcast Messages

When the notification behavior of PlayerInput is set to Send Messages or Broadcast Messages, you can set your app to respond to Actions by defining methods in components like so:

public class MyPlayerScript : MonoBehaviour
{
    // "jump" action becomes "OnJump" method.

    // If you're not interested in the value from the control that triggers the action, use a method without arguments.
    public void OnJump()
    {
        // your Jump code here
    }

    // If you are interested in the value from the control that triggers an action, you can declare a parameter of type InputValue.
    public void OnMove(InputValue value)
    {
        // Read value from control. The type depends on what type of controls.
        // the action is bound to.
        var v = value.Get<Vector2>();

        // IMPORTANT:
        // The given InputValue is only valid for the duration of the callback. Storing the InputValue references somewhere and calling Get<T>() later does not work correctly.
    }
}

The component must be on the same GameObject if you are using Send Messages, or on the same or any child GameObject if you are using Broadcast Messages.

When using Invoke Unity Events

When the notification behavior of PlayerInput is set to Invoke Unity Events, each Action has to be routed to a target method. The methods have the same format as the started, performed, and canceled callbacks on InputAction.

public class MyPlayerScript : MonoBehaviour
{
    public void OnFire(InputAction.CallbackContext context)
    {
    }

    public void OnMove(InputAction.CallbackContext context)
    {
        var value = context.ReadValue<Vector2>();
    }
}

Notification behaviors

You can use the Behavior property in the Inspector to determine how a PlayerInput component notifies game code when something related to the player has occurred.

The following options are available:

Behavior	Description
Send Messages	Uses GameObject.SendMessage on the GameObject that the PlayerInput component belongs to.
Broadcast Messages	Uses GameObject.BroadcastMessage on the GameObject that the PlayerInput component belongs to. This broadcasts the message down the GameObject hierarchy.
Invoke Unity Events	Uses a separate UnityEvent for each individual type of message. When this is selected, the events available on the PlayerInput are accessible from the Events foldout. The argument received by events triggered for Actions is the same as the one received by started, performed, and canceled callbacks.
Invoke CSharp Events	Similar to Invoke Unity Events, except that the events are plain C# events available on the PlayerInput API. You cannot configure these from the Inspector. Instead, you have to register callbacks for the events in your scripts. The following events are available: onActionTriggered (collective event for all actions on the player) onDeviceLost onDeviceRegained

In addition to per-action notifications, PlayerInput sends the following general notifications:

Notification	Description
DeviceLostMessage	The player has lost one of the Devices assigned to it. This can happen, for example, if a wireless device runs out of battery.
DeviceRegainedMessage	Notification that triggers when the player recovers from Device loss and is good to go again.

Device assignments

If the PlayerInput component has any Devices assigned, it matches these to the Control Schemes in the associated Action Asset, and only enables Control Schemes which match its Input Devices.

Each PlayerInput can have one or more Devices assigned to it. By default, no two PlayerInput components are assigned the same Devices, but you can force this; to do so, manually assign Devices to a player when calling PlayerInput.Instantiate, or call InputUser.PerformPairingWithDevice on the InputUser of a PlayerInput.

Debug information

When the Editor is in Play mode, each PlayerInput component instance displays a Debug section, as shown below.

The Debug section shows the User number (which starts counting from zero), the control Scheme, and the devices assigned to the PlayerInput instance.

UI input

The PlayerInput component can work together with an InputSystemUIInputModule to drive the UI system.

To set this up, assign a reference to a InputSystemUIInputModule component in the UI Input Module field of the PlayerInput component. The PlayerInput and InputSystemUIInputModule components should be configured to work with the same InputActionAsset for this to work.

Once you've completed this setup, when the PlayerInput component configures the Actions for a specific player, it assigns the same Action configuration to the InputSystemUIInputModule. In other words, the same Action and Device configuration that controls the player now also controls the UI.

If you use MultiplayerEventSystem components to dispatch UI events, you can also use this setup to simultaneously have multiple UI instances on the screen, each controlled by a separate player.

Notes:

• As a general rule, if you are using the PlayerInput workflow, you should read input through callbacks as described above, however if you need to access the input actions asset directly while using the PlayerInput component, you should access the PlayerInput component's copy of the actions, not InputSystem.actions. This is because the PlayerInput component performs device filtering to automatically assign devices to multiple players, so each instance has its own copy of the actions filtered for each player. If you bypass this by reading InputSystem.actions directly, the automatic device assignment won't work.

• This component is built on top of the public Input System API. As such, they don't do anything that you can't program yourself. They are meant primarily as an easy, out-of-the-box setup that eliminates much of the need for custom scripting.