New Input System overview in Unity

Introduction

The New Input System in Unity helps you read player actions like keyboard presses, mouse clicks, or gamepad buttons in a simple and flexible way.

You want to support multiple devices like keyboard, mouse, and gamepads without writing separate code for each.

You want to easily change controls or add new input methods without changing your game logic.

You want to handle complex input like combos or multiple buttons pressed together.

You want to support input rebinding so players can customize controls.

You want to improve input handling performance and reliability in your game.

Syntax

Unity

using UnityEngine;
using UnityEngine.InputSystem;

public class PlayerController : MonoBehaviour
{
    private PlayerInputActions inputActions;

    private void Awake()
    {
        inputActions = new PlayerInputActions();
    }

    private void OnEnable()
    {
        inputActions.Enable();
    }

    private void OnDisable()
    {
        inputActions.Disable();
    }

    private void Update()
    {
        Vector2 move = inputActions.Player.Move.ReadValue<Vector2>();
        // Use move vector to move player
    }
}

You create an Input Actions asset in Unity to define controls, then generate a C# class to access them.

Enable input actions when the object is active, and disable them when not to save resources.

Examples

This listens for the Jump action and calls the Jump() method when the button is pressed.

Unity

inputActions.Player.Jump.performed += ctx => Jump();

This reads the current value of the Move action, usually from a joystick or WASD keys.

Unity

Vector2 moveInput = inputActions.Player.Move.ReadValue<Vector2>();

Enable and disable input actions to control when input is processed.

Unity

inputActions.Player.Enable();
// Later
inputActions.Player.Disable();

Sample Program

This simple program shows how to read movement input and listen for a jump button press using the New Input System.

Unity

using UnityEngine;
using UnityEngine.InputSystem;

public class SimplePlayerController : MonoBehaviour
{
    private PlayerInputActions inputActions;

    private void Awake()
    {
        inputActions = new PlayerInputActions();
    }

    private void OnJump(InputAction.CallbackContext context)
    {
        Debug.Log("Jump pressed!");
    }

    private void OnEnable()
    {
        inputActions.Enable();
        inputActions.Player.Jump.performed += OnJump;
    }

    private void OnDisable()
    {
        inputActions.Player.Jump.performed -= OnJump;
        inputActions.Disable();
    }

    private void Update()
    {
        Vector2 move = inputActions.Player.Move.ReadValue<Vector2>();
        Debug.Log($"Moving: {move}");
    }
}

Important Notes

Remember to generate the C# class from your Input Actions asset before using it in code.

Use the Input Debugger window in Unity to see what inputs are detected during play.

Summary

The New Input System lets you handle many input devices easily.

You define actions in an asset and use generated code to read inputs.

Enable and disable input actions to control when input is active.

Practice

1. What is the main purpose of the New Input System in Unity?

easy

A. To create 3D models for games

B. To handle multiple input devices easily and flexibly

C. To manage game physics and collisions

D. To optimize game graphics performance

Solution

1. Step 1: Understand the role of input systems

   The New Input System is designed to manage inputs from devices like keyboard, mouse, gamepads, etc.

2. Step 2: Compare with other options

   Options B, C, and D relate to graphics, physics, or modeling, not input handling.

3. Final Answer:

   To handle multiple input devices easily and flexibly -> Option B

4. Quick Check:

   New Input System = device input management [OK]

Hint: Focus on input device management purpose [OK]

Common Mistakes:

• Confusing input system with graphics or physics
• Thinking it only handles keyboard input
• Assuming it creates game assets

2. Which of the following is the correct way to enable an input action in the New Input System?

easy

A. inputAction.Run();

B. inputAction.Start();

C. inputAction.Activate();

D. inputAction.Enable();

Solution

1. Step 1: Recall method names in New Input System

   The method to activate an input action is called Enable(), not Start(), Activate(), or Run().

2. Step 2: Confirm syntax correctness

   inputAction.Enable(); is the correct syntax to enable the action.

3. Final Answer:

   inputAction.Enable(); -> Option D

4. Quick Check:

   Enable() activates input actions [OK]

Hint: Remember Enable() activates input actions [OK]

Common Mistakes:

• Using Start() instead of Enable()
• Confusing method names with Activate() or Run()
• Forgetting parentheses after method name

3. Given this code snippet using the New Input System:

var moveAction = playerInput.actions["Move"];
moveAction.Enable();
var value = moveAction.ReadValue<Vector2>();
Debug.Log(value);

What does value represent?

medium

A. The current 2D vector input from the Move action

B. A boolean indicating if Move is pressed

C. The name of the Move action as a string

D. An integer representing Move action's ID

Solution

1. Step 1: Understand ReadValue<Vector2>()

   This method reads the current input value as a Vector2, typically for movement directions.

2. Step 2: Analyze the variable 'value'

   Since moveAction is enabled and ReadValue<Vector2>() is called, value holds the 2D input vector from the Move action.

3. Final Answer:

   The current 2D vector input from the Move action -> Option A

4. Quick Check:

   ReadValue<Vector2>() returns Vector2 input [OK]

Hint: ReadValue<Vector2>() returns 2D input vector [OK]

Common Mistakes:

• Thinking it returns a boolean
• Confusing value with action name or ID
• Not enabling the action before reading

4. What is wrong with this code snippet using the New Input System?

var jumpAction = playerInput.actions["Jump"];
jumpAction.ReadValue<float>();
jumpAction.Enable();

medium

A. The action is read before it is enabled

B. ReadValue<float>() is not a valid method

C. The action name "Jump" is invalid

D. Enable() should be called twice

Solution

1. Step 1: Check the order of method calls

   The code reads the input value before enabling the action, which means no input is active yet.

2. Step 2: Understand correct usage

   Enable() must be called before reading values to get valid input data.

3. Final Answer:

   The action is read before it is enabled -> Option A

4. Quick Check:

   Enable() must come before ReadValue() [OK]

Hint: Always enable input action before reading values [OK]

Common Mistakes:

• Reading input before enabling action
• Assuming ReadValue<float>() is invalid
• Thinking action names must be changed

5. You want to temporarily stop all player input during a cutscene using the New Input System. Which approach is best?

hard

A. Delete the input action asset during the cutscene

B. Set all input action callbacks to null

C. Call playerInput.actions.Disable() to disable all input actions

D. Ignore input values but keep actions enabled

Solution

1. Step 1: Understand disabling input actions

   Calling Disable() on the actions disables all input reading cleanly and temporarily.

2. Step 2: Evaluate other options

   Deleting assets is destructive, setting callbacks to null is error-prone, ignoring inputs wastes resources.

3. Final Answer:

   Call playerInput.actions.Disable() to disable all input actions -> Option C

4. Quick Check:

   Disable() cleanly stops input during cutscenes [OK]

Hint: Use Disable() to pause all inputs safely [OK]

Common Mistakes:

• Deleting input assets instead of disabling
• Nullifying callbacks causing errors
• Ignoring inputs wastes CPU