I'm trying to make my square jump in Unity 2D when I press Space button. I have the following code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Movement : MonoBehaviour
{
    public float moveSpeed;
    public float jumpSpeed;
    float moveX;
    Vector2 pos;

    // Update is called once per frame
    void Update()
    {
        MoveHorizontally();
        Jump();
    }
    void MoveHorizontally(){
        moveX = Input.GetAxis("Horizontal") * Time.deltaTime;
        pos.x = moveX * moveSpeed;

        transform.position = new Vector2(transform.position.x   pos.x,transform.position.y   pos.y);
    }
    void Jump(){
        if (Input.GetKeyDown("space")){
            GetComponent<Rigidbody2D>().AddForce(new Vector2(0,jumpSpeed * Time.deltaTime), ForceMode2D.Impulse);
            Debug.Log("Jumped!");
        }
    }
}

When I press Space button, "Jumped!" message shows up, but my square not jumping. Any idea?

Thanks a lot.

I tried using Input.GetKey function. It works, but that function keeps making my square go upwards if i keep holding Space button.

CodePudding user response：

U need to assing a value to jumpforce. and of course to the moveforce. if u dont wanna jump repeatly Just name a bool for checking if u are on ground. I use mine as" private bool = isGrounded". and try the code below. It makes ur jump a condition as a function of touching ground.

 private void OnCollisionEnter2D(Collision2D collision)
{

    if (collision.gameObject.CompareTag("Ground")) 
        isGrounded = true;
    

}

and here is my code for jump.

 public void PlayerJump() {

    if (Input.GetButtonDown("Jump") && isGrounded) {
        isGrounded = false;
        myBody.AddForce(new Vector2(0f, jumpForce), ForceMode2D.Impulse);
    }

}

whenever u jump it makes your bool variant false and whenever u touch ground it make ur bool true. Make sure "Ground" must be same exactly the tag your ground has.

CodePudding user response：

When you call AddForce() method you don't have to multiply with "Time.deltaTime".

What you can do is the following:

First cached your "Rigidbody2D" component from your Start() method because if you call it every frame it will affect your game performance.

private Rigidbody2D rigidbody2D;

void Start()
{
   rigidbody2D = GetComponent<Rigidbody2D>();
}

Second, instead of Update() method you should call the FixedUpdate() method which is recommended when you deal with Physics

void FixedUpdate()
{
    MoveHorizontally();
    Jump();
}

Third, on your Jump() method as I said on top you should not multiply the jump force with Time.deltaTime, instead do the following:

public float jumpForce = 10f;
public void Jump() 
{
    if (Input.GetKeyDown(KeyCode.Space)) 
    {
        rigidbody2D.AddForce(Vector2.up*jumpForce);
    }
}

You can adjust the jumpForce as you want. Also Vector2.up is a shorthand for writing Vector2(0, 1)

You can read more about Vector2 here Vector2.up Unity's Documentation