Player's jump is random and inconsistent...

Questions & Answers
1

The title is very self-explanatory. The issue is that, whenever I jump, the player’s jump height is very strange and random. I am basically making a platformer for a game jam and this issue is not very nice for platforming lol.

Here is the script:

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

public class PlayerMovement : MonoBehaviour
{
public float speed = 10f;
private Rigidbody2D rb;
public float jumpForce = 800f;

private bool allowJump;

public Transform point;
public LayerMask whatIsGround;
public float radius = 0.5f;

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

private void Update()
{
    float x = Input.GetAxisRaw("Horizontal");
    rb.velocity = new Vector2(x * speed * Time.deltaTime, rb.velocity.y);

    allowJump = Physics2D.OverlapCircle(point.position, radius, whatIsGround);
    if (Input.GetButtonDown("Jump") && allowJump == true)
    {
        rb.AddForce(Vector2.up * jumpForce * Time.deltaTime, ForceMode2D.Impulse);
    }

    else 
    {
        allowJump = false;
    }
}

}

so basically, I have some simple horizontal movement and some basic jumping. I have a bool that detects the ground. If it is overlapping, it will allow the player to jump, if there is nothing overlapping, player cannot jump so as to stop the player from jumping in mid-air.

Pls help :slight_smile:

3

Hey,
I think the issue is that your setting values to the Player’s rigidbody directly with your side to side movement.

Try to do the side to side movement in a different way, like by using Rigidbody.MovePosition (x * speed * Time.deltaTime).

I think that alone might make it more consistent.

What might also be an issue is that .AddForce is compounding the force that is already on the rigidbody, so you could (in your jump portion) set the rigidbody.velocity to Vector3.zero.

 private void Update()
 {
     float x = Input.GetAxisRaw("Horizontal");
     rb.MovePosition (transform.position + (x * speed * Time.deltaTime);

     allowJump = Physics2D.OverlapCircle(point.position, radius, whatIsGround);

     if (Input.GetButtonDown("Jump") && allowJump == true)
     {
        rb.velocity = Vector3.zero; 

         rb.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
     }
     else 
     {
         allowJump = false;
     }
 }
2

I had the same issue. This question has been posted many times, but to save you some hassle, don’t addForce. Instead, modify the velocity.y of the rigidbody. This will create a consistent and predictable jump height. @Pixelated_Studioz

4

It didn’t fix the bug still :frowning: but thanks anyways. I have noticed something, when I don’t multiply my jump power with Time.deltaTime, my player seems to jump fine (It doesn’t sky rocket or jump inconsistently)… Why is that so? I have looked around and found nothing related to this…

5

@Pixelated_Studioz

SO,

  1. Time.deltaTime is the time elapsed in seconds since the last frame, which depends on framerate, and is therefore, inconsistent as pointed out previously. ForceMode.Impulse adds the entire force in a single frame. So deltaTime causes spikes in the jump force.

  2. Why da frig is there an else statement setting allowJump to false? In my sense the code would not mess up, but my sense is flawed so it is better to trust Debug.Log and remove the else statement. It is not needed for the code to function.
    So, the final code is:-

    private Rigidbody2D rb;
public float jumpForce;
public float speed;
public bool allowJump;
public Transform point;
public LayerMask whatIsGround;
public float radius = 0.5f;
private void Start()
{
    rb = GetComponent<Rigidbody2D>();
}
private void Update()
{
    float x = Input.GetAxisRaw("Horizontal");
    rb.velocity = new Vector2(x * speed, rb.velocity.y);

    allowJump = Physics2D.OverlapCircle(transform.position, radius, whatIsGround);

    if (Input.GetKeyDown(KeyCode.UpArrow) && allowJump == true) // set this to your desired input method
    {
        Debug.Log("bum");
        rb.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
        allowJump = false;
    }
}

Also, consider using Physics2d.OverlapArea instead of OverlapCircle.