Unity_2D_Jump

JUMP

关于用unity开发2D跳跃游戏的一些思路

Case 01:

//跳跃最基础的实现方法：当空格按下时，给刚体一个向上的力
//缺陷：连按空格人会一直向上，下落的时候看起来人是飘飘的
public class Jump : MonoBehaviour
{
    public float jumpForce = 5f;

    private Rigidbody2D _rigidbody2D;
    private bool jumpRequest;
    
    void Start()
    {
        _rigidbody2D = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        if(Input.GetButtonDown("Jump"))
        {
            jumpRequest = true;
        }
    }
    private void FixedUpdate()
    {
        if(jumpRequest)
        {
            //ForceMode2D.Impulse
            _rigidbody2D.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
            jumpRequest = false;
        }
    }
}

//改进：点按和长按空格，起跳的速度不一样
//通过刚体当前的速度来判断是在上升还是在下落，给刚体不同的重力大小
public class JumpTest : MonoBehaviour
{
    public float jumpForce = 5f;
    public float fallMultiplier = 2.5f;
    public float lowJumpMultiplier = 2f;

    private Rigidbody2D _rigidbody2D;
    private bool jumpRequest;
    
    void Start()
    {
        _rigidbody2D = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        if(Input.GetButtonDown("Jump"))
        {
            jumpRequest = true;
        }
    }
    private void FixedUpdate()
    {
        if(jumpRequest)
        {
            _rigidbody2D.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);
            jumpRequest = false;
        }

        //当刚体在下落时
        if (_rigidbody2D.velocity.y < 0)
        {
            _rigidbody2D.gravityScale = fallMultiplier;
        }
        //当刚体在上升时，且空格不是按下的状态
        else if (_rigidbody2D.velocity.y > 0 && !Input.GetButton("Jump"))
        {
            _rigidbody2D.gravityScale = lowJumpMultiplier;
        }
        else
        {
            _rigidbody2D.gravityScale = 1f;
        }
    }
}

//改进：增加角色与环境的碰撞检测，解决角色可以在空中无限跳跃的问题
public class JumpBox : MonoBehaviour
{
    [Range(0, 10)] public float jumpForce = 5f;
    public LayerMask mask;
    public float boxHeight = 0.5f;

    private Vector2 playerSize;
    private Vector2 boxSize;

    private bool jumpRequest = false;
    private bool grounded = false;

    public float fallMultiplier = 2.5f;
    public float lowJumpMultiplier = 2f;

    private Rigidbody2D _rigidbody2D;

    void Start()
    {
        _rigidbody2D = GetComponent<Rigidbody2D>();
        playerSize = GetComponent<SpriteRenderer>().bounds.size;
        boxSize = new Vector2(playerSize.x * 0.5f, boxHeight);
    }

    void Update()
    {
        //当角色在地面按下空格时
        if (Input.GetButtonDown("Jump") && grounded)
        {
            jumpRequest = true;
        }
    }

    private void FixedUpdate()
    {
        if (jumpRequest)
        {
            _rigidbody2D.AddForce(Vector2.up * jumpForce, ForceMode2D.Impulse);

            jumpRequest = false;
            grounded = false;
        }
        //否则，为了让角色在其他情况下按空格都不会跳起来，需要检测角色是否在地面上
        else
        {
            //检测盒子的中心是角色的脚底
            Vector2 boxCenter = (Vector2)transform.position + (Vector2.down * playerSize * 0.5f);

            //
            if (Physics2D.OverlapBox(boxCenter, boxSize, 0, mask) != null)
            {
                grounded = true;
            }
            else
            {
                grounded = false;
            }
        }

        if (_rigidbody2D.velocity.y < 0)
        {
            _rigidbody2D.gravityScale = fallMultiplier;
        }
        else if (_rigidbody2D.velocity.y > 0 && !Input.GetButton("Jump"))
        {
            _rigidbody2D.gravityScale = lowJumpMultiplier;
        }
        else
        {
            _rigidbody2D.gravityScale = 1f;
        }
    }
}