Unity2D - 验证 isGround 是否正确

Question

我有一个脚本可以检测玩家何时触摸名为“Ground”的图层，它运行良好，但我的问题是当我使用允许我跳过平台的“Platform Effector 2D”时。所以，当我的角色通过平台时，我的布尔“isGrounded”为真，但他实际上不在地面，发生的情况是我用来检查的点是与地面层的对象“碰撞” .

我觉得我解释的不是很好，所以我在 Youtube 上上传了一个未列出的视频来展示

www.youtube.com/watch?v=EQpF4iSNC0Yt

这是代码

[Header("Components")]
[HideInInspector]public Rigidbody2D _rb;

[Header("Layer Masks")]
[SerializeField] private LayerMask groundLayer;

[Header("Movement Variables")]
[SerializeField] private float _movementAcceleration;
[SerializeField] private float _maxMoveSpeed;
[SerializeField] private float _linearDrag;
[SerializeField] private float dashPower;
private float horizontalDirection;
private bool changingDirection => (_rb.velocity.x > 0f &&  horizontalDirection < 0f) || (_rb.velocity.x < 0f && horizontalDirection > 0f);
public bool isFalling => _rb.velocity.y < 0.0f;
private bool isRunning => horizontalDirection != 0;

[Header("Jump Variables")]
[SerializeField] private float jumpForce = 12f;
[SerializeField] private float airLinearDrag = 2.5f;
[SerializeField] private float fallMultiplier = 8f;
[SerializeField] private float lowJumpFallMultiplier = 5f;
private bool canJump => Input.GetButtonDown("Jump") && isGround;
[Header("Ground Colission Variables")]
[SerializeField] private float groundRayCastLenght;

private bool isGround;
private bool jumped;    
private bool facinRight = true;
private Animator animator;
private SpriteRenderer sprite;
GameController controller;
public Transform    groundCheck         ;
public bool canPassThrough = false;

void Start()
{
    
    sprite = GetComponent<SpriteRenderer>();
    animator = GetComponent<Animator>();
    _rb = GetComponent<Rigidbody2D>();
    controller = FindObjectOfType<GameController>();
}

// Update is called once per frame
void Update()
{
    Debug.Log(_rb.velocity.y);
    isGround = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));

    horizontalDirection = GetInput().x;
    if(canJump && !controller.gamePaused){      
        Jump();
    }
    if(Input.GetKeyDown(KeyCode.LeftShift)){
        ApplyDash();
    }
    
    setAnimations();
    
}
void FixedUpdate()
{
    //CheckCollisions();
    if(!controller.gamePaused){
        //checkDirection();
        MoveCharacter();    
    }
    if(isGround){
        jumped = false;
        ApplyLinearDrag();
    }else{
        ApplyAirLinearDrag();
        FallMultiplier();
    }        
    
}

private Vector2 GetInput()
{
    
    return new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
}
private void MoveCharacter(){
    if(horizontalDirection < 0 && facinRight || horizontalDirection > 0 && !facinRight){
        checkDirection();
    }
    Vector3 v = _rb.velocity;
    _rb.AddForce(new Vector2(horizontalDirection* _movementAcceleration, 0f) );
    if(Mathf.Abs(_rb.velocity.x) > _maxMoveSpeed){
        v.x = Mathf.Sign(_rb.velocity.x) * _maxMoveSpeed;
        _rb.velocity = v;
        //_rb.velocity = new Vector2(Mathf.Sign(_rb.velocity.x) * _maxMoveSpeed, _rb.velocity.y );
    }
    
        
}
private void CheckCollisions(){
    isGround = Physics2D.Raycast(transform.position * groundRayCastLenght, Vector2.down, groundRayCastLenght, groundLayer);
}
private void ApplyLinearDrag(){
    if(Mathf.Abs(horizontalDirection) < 0.4f || changingDirection){
        _rb.drag = _linearDrag;
    }else{
        _rb.drag = 0f;
    }
}
private void ApplyDash(){
    _rb.AddForce(new Vector2(horizontalDirection * dashPower, _rb.velocity.y));
}
void ApplyAirLinearDrag(){
    _rb.drag = airLinearDrag;
}
void Jump(){
    jumped = true;
    if(horizontalDirection != 0){
        _rb.velocity = new Vector2(_rb.velocity.x, 0f);
        _rb.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);        
    }else{
        _rb.velocity = new Vector2(_rb.velocity.x, 0f);
        _rb.AddForce(Vector2.up * jumpForce * 2f, ForceMode2D.Impulse);
    }
    
}    
void OnDrawGizmos()
{
    Gizmos.color = Color.green;
    Gizmos.DrawLine(transform.position, transform.position + Vector3.down * groundRayCastLenght);
}
void FallMultiplier(){
    
    if(_rb.velocity.y < 0){
        _rb.gravityScale = fallMultiplier;
    }else if(_rb.velocity.y > 0 && !Input.GetButtonDown("Jump")){
        _rb.gravityScale = lowJumpFallMultiplier;
    }else{
        _rb.gravityScale = 1f;
    }
}
void setAnimations(){
    animator.SetBool("Run", isRunning && isGround);
    animator.SetBool("isGround", isGround);
    animator.SetBool("Jump", jumped);
    animator.SetBool("isFalling", isFalling);   
    animator.SetFloat("eixoY", Mathf.Abs(_rb.velocity.y));
}
void checkDirection(){
    facinRight = !facinRight;
    transform.localScale = new  Vector3( - transform.localScale.x, transform.localScale.y, transform.localScale.z);
}
void OnCollisionEnter2D(Collision2D other)
{
    if(LayerMask.LayerToName(other.gameObject.layer) == "Ground") //check layer is ground
    {
        if (gameObject.GetComponent<Rigidbody2D>().velocity.y <= 0) //check velocity.y is 0
        {
            Debug.Log("in ground"); //debug console
            canPassThrough = false;
        }else{
            Debug.Log("Not in ground");
            canPassThrough = true;
        }
    }
}

Answer 1

如果我们想在触摸的时候进行调试操作，我们可以通过检查在触摸的那一刻velocity.y是否为0来成功执行操作。

像这样：

private void OnCollisionEnter2D(Collision2D collision)
{
    if(LayerMask.LayerToName(collision.gameObject.layer) == "Ground") //check layer is ground
    {
        if (gameObject.GetComponent<Rigidbody2D>().velocity.y <= 0) //check velocity.y is 0
        {
            Debug.Log("in ground"); //debug console
        }
    }
}