Why New Input System overview in Unity? - Purpose & Use Cases

The Big Idea

What if you could make your game respond perfectly to any controller without rewriting your code?

The Scenario

Imagine trying to handle player controls in a game by checking every key or button manually, writing separate code for keyboard, mouse, and gamepad inputs.

It feels like juggling many balls at once, and missing one means the game won't respond correctly.

The Problem

This manual way is slow and confusing because you must write lots of code for each device.

It's easy to make mistakes, like forgetting to update input for a new controller or mixing input checks all over your code.

The Solution

The New Input System in Unity organizes all input devices and actions in one place.

It lets you define controls once and use them everywhere, making your code cleaner and easier to manage.

Before vs After

✗ Before

if (Input.GetKeyDown(KeyCode.Space)) { Jump(); } if (Input.GetButtonDown("Fire1")) { Shoot(); }

✓ After

playerInput.actions["Jump"].performed += ctx => Jump(); playerInput.actions["Shoot"].performed += ctx => Shoot();

What It Enables

It enables you to support many devices and complex input setups effortlessly, making your game feel smooth and responsive.

Real Life Example

Think of a racing game where players can use keyboard, gamepad, or steering wheel without changing any code.

The New Input System handles all these inputs seamlessly.

Key Takeaways

Manual input handling is slow and error-prone.

The New Input System centralizes input management.

It makes supporting multiple devices easy and your code cleaner.

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