如何让玩家在统一 2d 中停止无限跳跃答案

【问题标题】：How to make player stop infinite jump in unity 2d如何让玩家在统一 2d 中停止无限跳跃
【发布时间】：2021-04-04 06:07:52
【问题描述】：

所以我才刚接触 Unit 2 天，我遇到了我的玩家在空中跳跃的问题。我可以继续点击空格键，我的玩家会继续跳跃而不是停止，我正在努力做到这一点，所以玩家只能在地面上而不是空中跳跃。我一直在尝试很多教程，其中大多数只是让我的游戏冻结并且不再工作。我也一直在尝试找出如何使用地面检查，但我仍然不确定如何做到这一点。

这是我知道的代码。

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

public class PM : MonoBehaviour
{
    public float moveSpeed;
    public float jumpHeight;
    Rigidbody2D rb;


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

    void Update() {
    float moveDir = Input.GetAxis("Horizontal") * moveSpeed;
    rb.velocity = new Vector2(moveDir, rb.velocity.y);

    // Your jump code:
    if (Input.GetKeyDown(KeyCode.Space))
    {
        rb.velocity = new Vector2(rb.velocity.x, jumpHeight);
    }
   }
}

【问题讨论】：

标签： c# unity3d 2d

【解决方案1】：

是的，您确实需要进行某种地面检查。网上有很多很好的教程，例如https://www.youtube.com/watch?v=c3iEl5AwUF8&t=17s（“在Unity中进行地面检查的3种方法”）。

要实现简单的“raycast down check”，您需要为地面/平台分配一个与玩家图层不同的图层蒙版。在本例中，我添加了一个名为“Ground”的新图层。

然后您可以使用这个简单的代码进行测试。

BoxCollider2D boxColliderPlayer;
int layerMaskGround;
float heightTestPlayer;

void Start()
{
    rb = GetComponent<Rigidbody2D>();

    // Get the player's collider so we can calculate the height of the character.
    boxColliderPlayer = GetComponent<BoxCollider2D>();
    // We do the height test from the center of the player, so we should only check
    // halft the height of the player + some extra to ignore rounding off errors.
    heightTestPlayer = boxColliderPlayer.bounds.extents.y + 0.05f;
    // We are only interested to get colliders on the ground layer. If we would
    // like to jump ontop of enemies we should add their layer too (which then of
    // course can't be on the same layer as the player).
    layerMaskGround = LayerMask.GetMask("Ground");
}

void Update()
{
    float moveDir = Input.GetAxis("Horizontal") * moveSpeed;
    rb.velocity = new Vector2(moveDir, rb.velocity.y);

    // Your jump code:
    if (Input.GetKeyDown(KeyCode.Space) && IsGrounded() )
    {
        rb.velocity = new Vector2(rb.velocity.x, jumpHeight);
    }
}


/// <summary>
/// Simple check to see if our character is no the ground. 
/// </summary>
/// <returns>Returns <c>true</c> if the character is grounded.</returns>
private bool IsGrounded()
{
    // Note that we only check for colliders on the Ground layer (we don't want to hit ourself). 
    RaycastHit2D hit = Physics2D.Raycast(boxColliderPlayer.bounds.center, Vector2.down, heightTestPlayer, layerMaskGround);
    bool isGrounded = hit.collider != null;
    // It is soo easy to make misstakes so do a lot of Debug.DrawRay calls when working with colliders...
    Debug.DrawRay(boxColliderPlayer.bounds.center, Vector2.down * heightTestPlayer, isGrounded ? Color.green : Color.red, 0.5f);
    return isGrounded;
}

如你所见，我希望玩家角色拥有 BoxCollider2D - 我猜你已经拥有了，否则角色会掉到地上）。做 2D 的东西时要小心，不要混合普通的 3D 对撞机。

【讨论】：