2d-platformer climb

Questions & Answers
1

I’m trying to make a 2d-platformer. In this game I want to make the player be able to climb on ladders. I haven’t found a good tutorial that helped me. The console prints out “I’m standing on ground.” but I can’t climb the ladder. I would appreciate help.

This is my script:

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

public class PlayerMovement : MonoBehaviour
{
    Rigidbody2D rb2d;

public float maxSpeed = 5f;
public bool onLadder = false;

private void Start()
{
    rb2d = GetComponent<Rigidbody2D>();
}

private void FixedUpdate()
{

}

void Climbing()
{
    float y = Input.GetAxis("Vertical");

    Vector2 movement = new Vector3(0.0f, y, 0.0f);
    rb2d.velocity = movement.normalized * maxSpeed;
}

private void OnTriggerEnter2D(Collider2D other)
{
    if (other.tag == "Ladder")
    {
        onLadder = true;

        if (onLadder == true && Input.GetKeyDown("w"))
        {
            Climbing();
        }

        Debug.Log("I'm on ladder.");
    }
    else
    {
        onLadder = false;
    }
}

}

2

Your problem seems to be that you are only checking if the player is pressing the ‘W’ key when the player enters the trigger.

3

The problem is that OnTriggerEnter2D() only gets called once. Your velocity will be changed, but will quickly drop down again because it only runs once. Change your function to OnTriggerStay2D(). That will check if you are pressing W continuously while inside the trigger.

More Explination:

When working with triggers and colliders there are three states you can possibly have:

  • Enter : When you first enter the trigger or collider (Gets Called only Once/ Resets when you leave)
  • Stay: Runs as long as you are within the trigger or collider
  • Exit: When you leave trigger or collider (Gets Called Only Once / Resets when you enter again)

However, a different way of doing it is attaching the following script to the ladded object:

using UnityEngine;
using System.Collections;

public class ladder () {
  
  OnTriggerEnter2D (Collider other) {
   // Stops the player from being affected by gravity while on ladder
    if (other.Tag == "Player")
      other.gameObject.GetComponent<RigidBody2D> ().gravityScale = 0;
 }

OnTriggerStay2D (Collider other) {
  if(!(other == "Player"))
    return;

  float y = Input.GetAxis ("Vertical");
       other.transform.translate (new Vector3 (0, other, 0));
}

OnTriggerExit2D (Collider other) {
   // Stops the player from being affected by gravity while on ladder
    if (other.Tag == "Player")
      other.gameObject.GetComponent<RigidBody2D> ().gravityScale = 1;
 }
}