我的角色在Unity2D中執行了意外的第三跳

Question

你好！

我目前正在Unity引擎中開發2D平台游戲，在那里我創建了可以進行雙倍跳躍的角色。
在一開始的時候一切都很好，但是我現在已經意識到，存在一個打破游戲規則的錯誤，使他能夠執行第三跳（出於某種原因）。 而且我不能為了找出問題所在。

PlayerController.cs

using UnityEngine;
using System.Collections;

public class PlayerController : MonoBehaviour {

    /*
    TODO: Find out why the character ocationally
    gets 3 jumps instead of 2.
    I think it's the "isGrounded" that returns
    a false posetive.
    */

[Header("Ground Recognition")]
public BoxCollider2D groundCollider;
public LayerMask groundAbles;

[Header("Audio")]
public GameObject jumpSound = null;

[Header("Visual")]
public GameObject jumpEffect = null;


float speed = 5f;
int maxJumps = 2;
int currentJumps = 0;

bool isGrounded = false;
float boundsLength = 0;

Vector3 movement;
// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update() {
    CheckGroundCollision();
    JumpLogic();

    movement = new Vector3(Input.GetAxis("Horizontal") * speed, 0, 0);
    movement *= Time.deltaTime;
    transform.position += movement;

    CheckGroundCollision();
}

void CheckGroundCollision()
{
    isGrounded = groundCollider.IsTouchingLayers(groundAbles);
}

void JumpLogic()
{

    if (isGrounded)
        currentJumps = 0;

    if (Input.GetButtonDown("Jump") && currentJumps < maxJumps)
    {
        GameObject newJumpSound = (GameObject)GameObject.Instantiate(jumpSound, (Vector2)transform.position, transform.rotation);
        GameObject newJumpEffect = (GameObject)GameObject.Instantiate(jumpEffect, (Vector2)transform.position - new Vector2(0, 0.25f), transform.rotation);
        GameObject.Destroy(newJumpEffect, 0.2f);
        GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, 0);
        GetComponent<Rigidbody2D>().AddForce(new Vector2(0, 10), ForceMode2D.Impulse);
        currentJumps++;
        CheckGroundCollision();
    }
}
}  

感謝所有幫助！

Answer 1

在void JumpLogic() ，您正在調用

currentJumps++;
CheckGroundCollision();

第一次按下跳轉鍵時， currentJumps變為1（currentJumps ++），然后isGrounded再次變為true（因為在當前幀中尚未應用物理方法，並且角色仍在接觸地面圖層蒙版）。 因此，下次調用JumpLogic() ，由於if (isGrounded) currentJumps = 0;因此currentJumps重置為零if (isGrounded) currentJumps = 0; 在運行跳轉鍵代碼之前。

我建議刪除對CheckGroundCollision();的最后一次調用CheckGroundCollision(); 在void JumpLogic()內部。 無論如何，它們都在Update()內部被調用，其順序似乎可行。

希望對您有所幫助！

更新：我剛剛注意到您還調用CheckGroundCollision(); 第二次在Update()本身內部。 那也將重置跳轉變量。

嘗試對原始代碼進行以下修改：

void Update() {
    CheckGroundCollision();
    JumpLogic();

    movement = new Vector3(Input.GetAxis("Horizontal") * speed, 0, 0);
    movement *= Time.deltaTime;
    transform.position += movement;

    //** NOTE- REMOVED THIS LINE
}

...

void JumpLogic()
{

    if (isGrounded)
        currentJumps = 0;

    if (Input.GetButtonDown("Jump") && currentJumps < maxJumps)
    {
        GameObject newJumpSound = (GameObject)GameObject.Instantiate(jumpSound, (Vector2)transform.position, transform.rotation);
        GameObject newJumpEffect = (GameObject)GameObject.Instantiate(jumpEffect, (Vector2)transform.position - new Vector2(0, 0.25f), transform.rotation);
        GameObject.Destroy(newJumpEffect, 0.2f);
        GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, 0);
        GetComponent<Rigidbody2D>().AddForce(new Vector2(0, 10), ForceMode2D.Impulse);
        currentJumps++;

        //** NOTE- REMOVED THIS LINE
    }
}

希望對您有所幫助！

Answer 2

我建議讓對撞機指示播放器控制器isGrounded的狀態，而不要查詢對撞機。 例如，繼續執行andeart的建議，您的代碼可能更像以下內容

void Update() {
    JumpLogic();

    movement = new Vector3(Input.GetAxis("Horizontal") * speed, 0, 0);
    movement *= Time.deltaTime;
    transform.position += movement;
}

//let the collider indicate to the player controller when
//a collision occurs, then determine if this collision is relevant
void OnCollisionEnter2D(Collision2D coll) {
    if(coll.IsTouchingLayers(groundAbles))    
      isGrounded = true;

    // or do some other check using layers or tags ....
}

void JumpLogic()
{
    if (isGrounded)
        currentJumps = 0;

    if (Input.GetButtonDown("Jump") && currentJumps < maxJumps)
    {
        GameObject newJumpSound = (GameObject)GameObject.Instantiate(jumpSound, (Vector2)transform.position, transform.rotation);
        GameObject newJumpEffect = (GameObject)GameObject.Instantiate(jumpEffect, (Vector2)transform.position - new Vector2(0, 0.25f), transform.rotation);
        GameObject.Destroy(newJumpEffect, 0.2f);
        GetComponent<Rigidbody2D>().velocity = new Vector2(GetComponent<Rigidbody2D>().velocity.x, 0);
        GetComponent<Rigidbody2D>().AddForce(new Vector2(0, 10), ForceMode2D.Impulse);
        currentJumps++;
    }
}

請參閱Collider2D.IsTouchingLayers，尤其是最下面的段落，它暗示着IsTouchingLayers方法相對於對撞機可能無法提供最准確的結果。