Input action maps in Unity

Introduction

Input action maps help organize and manage different player controls in a game. They group related input actions so you can easily switch or handle controls.

You want to separate controls for walking, running, and jumping.

You need different controls for menus and gameplay.

You want to support multiple control schemes like keyboard and gamepad.

You want to enable or disable certain controls during specific game states.

You want to keep input code clean and easy to manage.

Syntax

Unity

InputActionMap actionMap = new InputActionMap("PlayerControls");
actionMap.AddAction("Jump", binding: "space");
actionMap.Enable();

An InputActionMap groups multiple InputActions under one name.

You enable the whole map to listen for its actions.

Examples

This creates a map named 'Gameplay' with Move and Jump actions bound to keyboard keys.

Unity

var actionMap = new InputActionMap("Gameplay");
actionMap.AddAction("Move", binding: "<Keyboard>/w");
actionMap.AddAction("Jump", binding: "<Keyboard>/space");
actionMap.Enable();

This map handles menu navigation using a gamepad.

Unity

var menuMap = new InputActionMap("Menu");
menuMap.AddAction("Navigate", binding: "<Gamepad>/dpad");
menuMap.AddAction("Select", binding: "<Gamepad>/buttonSouth");
menuMap.Enable();

Sample Program

This script creates a Player input action map with a Jump action bound to the spacebar. When space is pressed, it logs "Jump pressed!" to the console.

Unity

using UnityEngine;
using UnityEngine.InputSystem;

public class PlayerInputExample : MonoBehaviour
{
    private InputActionMap playerActionMap;
    private InputAction jumpAction;

    void Awake()
    {
        playerActionMap = new InputActionMap("Player");
        jumpAction = playerActionMap.AddAction("Jump", binding: "<Keyboard>/space");
        jumpAction.performed += ctx => Debug.Log("Jump pressed!");
    }

    void OnEnable()
    {
        playerActionMap.Enable();
    }

    void OnDisable()
    {
        playerActionMap.Disable();
    }
}

Important Notes

Always enable your InputActionMap to start receiving input events.

You can disable maps to temporarily stop input without removing actions.

Use descriptive names for maps and actions to keep your code clear.

Summary

Input action maps group related input actions for better control management.

Enable or disable maps to control when inputs are active.

Bind actions to keys or buttons inside maps to handle player input cleanly.

Practice

1.

What is the main purpose of an Input Action Map in Unity's Input System?

easy

A. To handle audio playback

B. To render graphics on the screen

C. To store game settings permanently

D. To group related input actions for easier management

Solution

1. Step 1: Understand what Input Action Maps do

   Input Action Maps group related input actions, like movement or UI controls, to organize inputs.

2. Step 2: Compare with other options

   Rendering graphics, storing settings, and audio playback are unrelated to input action maps.

3. Final Answer:

   To group related input actions for easier management -> Option D

4. Quick Check:

   Input Action Maps = Group inputs [OK]

Hint: Remember: Action maps group inputs logically [OK]

Common Mistakes:

• Confusing input maps with graphics or audio systems
• Thinking action maps store data permanently
• Assuming action maps handle rendering

2.

Which of the following is the correct way to enable an InputActionMap named playerControls in C#?

?

easy

A. playerControls.Activate();

B. playerControls.Start();

C. playerControls.Enable();

D. playerControls.Run();

Solution

1. Step 1: Recall the method to enable input action maps

   The correct method to enable an InputActionMap is Enable().

2. Step 2: Verify other options

   Start(), Activate(), and Run() are not valid methods for InputActionMap.

3. Final Answer:

   playerControls.Enable(); -> Option C

4. Quick Check:

   Enable() activates input maps [OK]

Hint: Use Enable() to start input action maps [OK]

Common Mistakes:

• Using Start() instead of Enable()
• Confusing method names with other Unity components
• Forgetting to enable the action map before use

3.

Given the following code snippet, what will be the output when playerControls is enabled and the player presses the jump button?

var playerControls = new PlayerInputActions();
playerControls.Player.Jump.performed += ctx => Debug.Log("Jump pressed");
playerControls.Player.Enable();
// Player presses jump button

medium

A. Jump pressed

B. No output

C. NullReferenceException

D. Jump pressed twice

Solution

1. Step 1: Understand event subscription and enabling

   The code subscribes to the Jump action's performed event and enables the Player action map.

2. Step 2: Predict output on jump button press

   When the jump button is pressed, the subscribed lambda logs "Jump pressed" once.

3. Final Answer:

   Jump pressed -> Option A

4. Quick Check:

   Subscribed event triggers log once [OK]

Hint: Enabling action map triggers subscribed events [OK]

Common Mistakes:

• Forgetting to enable the action map
• Expecting multiple logs without multiple subscriptions
• Confusing event names or missing subscription

4.

What is wrong with this code snippet that tries to disable an input action map?

var controls = new PlayerInputActions();
controls.Player.Disable();
controls.Player.performed += ctx => Debug.Log("Action performed");

medium

A. The event subscription is on the action map instead of a specific action

B. Disable() method does not exist on InputActionMap

C. You cannot disable an action map before subscribing to events

D. The code should call Enable() before Disable()

Solution

1. Step 1: Check event subscription target

   The code subscribes to performed on controls.Player, which is an InputActionMap, not an InputAction.

2. Step 2: Understand correct subscription

   Events like performed belong to InputActions, e.g., controls.Player.Jump.performed, not the whole map.

3. Final Answer:

   The event subscription is on the action map instead of a specific action -> Option A

4. Quick Check:

   Subscribe events on actions, not maps [OK]

Hint: Subscribe events on actions, not action maps [OK]

Common Mistakes:

• Subscribing events on InputActionMap instead of InputAction
• Confusing Disable() method availability
• Assuming order of Enable/Disable affects subscription

5.

You want to switch between two control schemes, Keyboard and Gamepad, during gameplay using input action maps. Which approach correctly handles this switch?

?

hard

A. Use only one action map and ignore control schemes

B. Disable the current action map and enable the other action map

C. Create new input actions every time you switch

D. Enable both action maps at the same time

Solution

1. Step 1: Understand control scheme switching

   Switching control schemes means activating one input action map and deactivating the other to avoid conflicts.

2. Step 2: Evaluate options

   Enabling both maps causes input conflicts; creating new actions wastes resources; ignoring schemes loses flexibility.

3. Final Answer:

   Disable the current action map and enable the other action map -> Option B

4. Quick Check:

   Switch by toggling action maps [OK]

Hint: Toggle action maps to switch control schemes [OK]

Common Mistakes:

• Enabling multiple action maps causing input conflicts
• Recreating actions unnecessarily
• Ignoring control scheme differences