Player won't jump in build but works just fine in the editor

Unity Engine
1

Hi, I’m making a “test game” to experiment and learn how Unity works. I have a very simple platformer game and works just fine in the editor, but when I Build and Run it for some reason the player won’t jump, everything else works as it should. Any help is welcomed.

Here’s the code that is called for when the player should jump:

[SerializeField]
private float jumpForce = 11f;
private float jumpTimeCounter;
public float jumpTime;
private bool isJumping;
const float groundCheckRadius = 0.37f;
private float movementX;
private Rigidbody2D myBody;
[SerializeField] private Transform groundCheckCollider;
[SerializeField] LayerMask groundLayer;
[SerializeField] private bool isGrounded = false;

private void Start() {
        dashTime = starDashTime;
        myBody = GetComponent<Rigidbody2D>();
    }

void Update()
    {
        PlayerJump();
        GroundCheck();
        WallJump();
        FlipAction();
        Dash();
    }

void PlayerJump() {
        if ((Input.GetButtonDown("Jump")) && isGrounded) {
            isJumping = true;
            jumpTimeCounter = jumpTime;
            myBody.AddForce(new Vector2(0f, jumpForce), ForceMode2D.Impulse);
        }

        //The longer the player holds the JUMP button the higher it will jump
        if (Input.GetButton("Jump") && isJumping) {
            if (jumpTimeCounter > 0) {
                myBody.AddForce(new Vector2(0f, jumpForce), ForceMode2D.Impulse);
                jumpTimeCounter -= Time.deltaTime;
            }
        } else {
            isJumping = false;
        }

        if (Input.GetButtonUp("Jump")) {
            isJumping = false;
        }
    }

void GroundCheck() {
        isGrounded = false;
        Collider2D[] colliders = Physics2D.OverlapCircleAll(groundCheckCollider.position, groundCheckRadius, groundLayer);
        if (colliders.Length > 0) {
            isGrounded = true;
            canDash = true;
        }
    }
2

Check the log for any errors in the build.

Beyond that, watch the log and do this:

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also put in Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

1 Like
3

ALSO: you are putting physics stuff under Update().

Don’t do that. It belongs in FixedUpdate().

However, Input.GetKeyDown() is only valid in Update() so you will need to refactor your code a bit.

It’s up to you to buffer the input from Update() and act on it in FixedUpdate()