如何在Unity 2d中保持恒定的速度？

Question

我是Unity和C＃的新手。我正在努力开发自己的第一款游戏，很多语法使我感到困惑。我试图在按下“ a”或“ d”或方向键时用力在x轴上移动我的精灵，但看来我的精灵没有以恒定的速度移动。

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

public class playerMovement : MonoBehaviour
{
    public float vel = .5f;
    public float jumpVel = 10f;
    public bool isGrounded = false;
    private Rigidbody2D rb;

    // Start is called before the first frame update
    void Start()
    {
        rb = transform.GetComponent<Rigidbody2D>();
    }

    // Update is called once per frame
    void Update()
    {
        //Vector3 move = new Vector3(Input.GetAxisRaw("Horizontal"), 0f,0f);
        //transform.position += move * Time.deltaTime * vel;
        if(Input.GetAxisRaw("Horizontal") == 1){
            rb.AddForce(Vector2.right*vel, ForceMode2D.Force);
        }else if(Input.GetAxisRaw("Horizontal") == -1){
            rb.AddForce(Vector2.right*-vel, ForceMode2D.Force);
        }
        if(Input.GetKeyDown(KeyCode.Space) && isGrounded == true){
            rb.velocity = Vector2.up * jumpVel;
        }

    }
}

Answer 1

这是因为您正在使用rb.AddForce向其添加力量，它会在每次播放时增加速度，以便玩家移动，我建议使用CharacterMovement组件，但是如果要使用Rigidbody2d，则是最佳解决方案我能想到的是：

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

public class playerMovement : MonoBehaviour
{
    public float vel = .5f;
    public float jumpVel = 10f;
    public bool isGrounded = false;
    private Rigidbody2D rb;
    public float maxbel = 10f;

    // Start is called before the first frame update
    void Start()
    {
        rb = transform.GetComponent<Rigidbody2D>();
    }

    // Update is called once per frame
    void Update()
    {
        //Vector3 move = new Vector3(Input.GetAxisRaw("Horizontal"), 0f,0f);
        //transform.position += move * Time.deltaTime * vel;
        if(Input.GetAxisRaw("Horizontal") == 1 &&rb.velocity.x<=maxvel){
            rb.AddForce(Vector2.right*vel, ForceMode2D.Force);
        }else if(Input.GetAxisRaw("Horizontal") == -1 && rb.velocity.x>=-maxvel){
            rb.AddForce(Vector2.right*-vel, ForceMode2D.Force);
        }
        if(Input.GetKeyDown(KeyCode.Space) && isGrounded == true){
            rb.velocity = Vector2.up * jumpVel;
        }

    }
}

所以，在这个答案中，浮子maxvel（代表最大速度），这个浮子用于知道您想要的偶极子速度（您应该自己进行调整，我只是为代码工作提供了一些参考），我还调用rb.velocity.x来检查水平轴上的实际速度，因此我决定不直接更改该速度，因为那样会使该速度从0变为您放置的速度，使用addforce使其工作平稳；] >