Input axis for smooth movement in Unity - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Unity C# code for horizontal input?

Consider the following Unity C# script snippet inside Update(). What will be the value of moveHorizontal if the player presses the right arrow key for a short moment?

Unity

float moveHorizontal = Input.GetAxis("Horizontal");
Debug.Log(moveHorizontal);

A Always 1 immediately when the key is pressed

B A value smoothly increasing from 0 to 1 over a short time

C Always 0 regardless of input

D A value instantly jumping between -1 and 1 with no smoothing

💡 Hint

Think about how Input.GetAxis works compared to Input.GetAxisRaw.

Input.GetAxis returns a value that changes smoothly from 0 to 1 when pressing a key, allowing smooth movement. It does not jump immediately to 1.

❓ Predict Output

intermediate

What does this code print when pressing left arrow key?

Given this code snippet inside Update(), what will be printed when the player presses the left arrow key?

Unity

float moveHorizontal = Input.GetAxisRaw("Horizontal");
Debug.Log(moveHorizontal);

A Always 0 regardless of input

B A value smoothly changing from 0 to -1

C A value of -1 immediately when the key is pressed

D A value of 1 immediately when the key is pressed

💡 Hint

Input.GetAxisRaw returns raw input without smoothing.

Input.GetAxisRaw returns -1 immediately when pressing left arrow, no smoothing.

🔧 Debug

advanced

Why does this movement feel jerky?

This Unity C# code moves a player horizontally using Input.GetAxisRaw. Why might the movement feel jerky?

Unity

float move = Input.GetAxisRaw("Horizontal");
transform.Translate(move * speed * Time.deltaTime, 0, 0);

A Because Input.GetAxisRaw returns values instantly without smoothing, causing sudden jumps

B Because Time.deltaTime is not used, causing inconsistent movement

C Because transform.Translate is called outside Update, causing lag

D Because speed is multiplied twice, causing too fast movement

💡 Hint

Think about how input smoothing affects movement feel.

Using Input.GetAxisRaw causes instant input changes, which can make movement feel jerky compared to smooth input.

🧠 Conceptual

advanced

How to achieve smooth acceleration using input axis?

Which approach best achieves smooth acceleration and deceleration for player movement in Unity?

A Use Input.GetAxisRaw and add a fixed value to position each frame

B Use Input.GetAxisRaw and multiply by speed without Time.deltaTime

C Use Input.GetAxis and set position directly without Time.deltaTime

D Use Input.GetAxis and multiply by speed and Time.deltaTime in Update

💡 Hint

Smooth input and frame-rate independent movement are key.

Using Input.GetAxis provides smooth input values, and multiplying by Time.deltaTime ensures smooth movement regardless of frame rate.

❓ Predict Output

expert

What is the value of 'velocity' after this code runs?

Given this Unity C# code snippet inside Update(), what is the value of velocity after pressing right arrow key for 1 second continuously? Assume speed = 5f and frame rate is 60 FPS.

Unity

float moveInput = Input.GetAxis("Horizontal");
float velocity = 0f;
velocity += moveInput * speed * Time.deltaTime;

A Always 0 because velocity is reset each frame

B Exactly 5 immediately after pressing the key

C Approximately 0.0833 (5 * 1/60) after one frame, accumulating over frames

D Approximately 1 after one second

💡 Hint

Consider variable scope and how 'velocity' is updated each frame.

The variable velocity is reset to 0 every frame because it is declared inside Update(). So it never accumulates.