Platformer Jumping Inconsistencies

Unity Engine
1

For the most part, my jump script works. However, I noticed that there is a rare exception, namely that if the jump button is pressed in the exact moment that the player hits the ground, the player will sometimes be unable to jump. The timing to repeat this bug is strict but I can’t figure out what is causing the problem. I am wondering if it has to do with the timings for when Unity calls the functions OnTriggerEnter2D and Update. For reference here is my player script:

using UnityEngine;
using System.Collections;

public class Player : MonoBehaviour {

    public float speed = 50f;
    public float maxSpeed = 3f;
    public float jumpPower = 200f;
    public bool grounded;

    private Rigidbody2D rigidBody;
    private Animator animator;


    void Start () {
        rigidBody = gameObject.GetComponent<Rigidbody2D>();
        animator = gameObject.GetComponent<Animator>();
    }
   

    void Update () {
        animator.SetBool("Grounded", grounded);
        animator.SetFloat("Speed", Mathf.Abs(Input.GetAxis("Horizontal")));

        if (Input.GetAxis("Horizontal") < -0.1f) {
            transform.localScale = new Vector3(-1, 1, 1);
        }

        if (Input.GetAxis("Horizontal") > 0.1f) {
            transform.localScale = new Vector3(1, 1, 1);
        }

        if (Input.GetButtonDown("Jump") && grounded)
        {
                rigidBody.AddForce(Vector2.up * jumpPower);
        }
    }

    void FixedUpdate()
    {
        //Horizontal and Vertical Input
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical");

        //Fake friction
        Vector3 friction = rigidBody.velocity;
        friction.x *= 0.75f;
        if (grounded) {
            rigidBody.velocity = friction;
        }

       //Movement
        rigidBody.AddForce(Vector2.right * speed * h);

        if (rigidBody.velocity.x > maxSpeed) {
            rigidBody.velocity = new Vector2(maxSpeed, rigidBody.velocity.y);
        }

        if (rigidBody.velocity.x < -maxSpeed) {
            rigidBody.velocity = new Vector2(-maxSpeed, rigidBody.velocity.y);
        }
    }
}

And here is the script that checks for ground collision:

using UnityEngine;
using System.Collections;

public class GroundCheck : MonoBehaviour {

    private Player player;

    // Use this for initialization
    void Start() {
        player = gameObject.GetComponentInParent<Player>();
    }

    void OnTriggerEnter2D(Collider2D collider) {
        player.grounded = true;
    }

    void OnTriggerStay2D(Collider2D collider) {
        player.grounded = true;
    }

    void OnTriggerExit2D(Collider2D collider) {
        player.grounded = false;
    }
}

Any ideas?

2

Rather use a raycast to check for grounding. Works better. With Raycast you can also check the tag on the object you land.
Here is how I did it Just a snippet of code( JS )

/***********************************************************************
* Function checks if Player is Grounded
***********************************************************************/
function Grounded(){
//Draw the ray 
Debug.DrawRay(transform.position,-Vector2.up*rayDistanceToGround,Color.red);

    hitGround = Physics2D.Raycast(transform.position, -Vector2.up, rayDistanceToGround,playerMask);
   if (hitGround.collider != null) {
   Debug.Log(hitGround.collider.tag);
   groundedState = true;
//Change some other states back 
    jumpingState = false;
   wallSliding = false;
   secondJump=false;

   }
   else groundedState = false;
}
3

I appreciate the reply, but if you don’t mind explaining how/why the raycast works better I’d greatly appreciate it. I am still new to Unity so things like this will really go a long way for me.