Question

[解决]

我一直在跟随Udemy的“通过制作游戏学习编码”课程（Block Breaker Section），我有一个小小的问题。恼人的问题。我的桨没有正确地夹住我输入的值。我本来没有遇到任何麻烦，但我决定在左侧有一个带有速度控制器，声音控制器和生命的小菜单。这意味着我只能说我希望拨片停在屏幕边缘。

观察到的行为：

划水板不会将自身限制在我放入的区域。随着屏幕尺寸的改变，划水板将离开屏幕或在屏幕中间某处停止。

我想要它做什么：

我希望当它碰到左边菜单的边缘时停止，当它击中右边的屏幕时停止。我也希望这与我的屏幕尺寸变化保持一致。所以基本上我需要一个可以确定这些点的数学方程式，它需要能够根据屏幕尺寸进行调整。

以下是我的划桨代码：

using UnityEngine;
using System.Collections;
public class Paddle : MonoBehaviour {

    public Texture texture;

    public void Update () {

        Vector3 paddlePos = new Vector3 (0.5f, this.transform.position.y , 0f);

        float mousePosInBlocks = Input.mousePosition.x;

        paddlePos.x = Mathf.Clamp(mousePosInBlocks, //Left Vaule, //Right Value);

        this.transform.position = paddlePos;
    }
}

Answer 1

这是因为Input.mousePosition返回鼠标在屏幕上的位置，而不是在世界空间中。只需将mousePosition转换为世界位置，然后将其值分配给mousePosInBlocks。

using UnityEngine;
using System.Collections;
public class Paddle : MonoBehaviour {

    public Texture texture;

    public void Update () {

        Vector3 paddlePos = new Vector3 (0.5f, this.transform.position.y , 0f);

        float mousePosInBlocks = Camera.main.ScreenToWorldPoint(Input.mousePosition).x;

        paddlePos.x = Mathf.Clamp(mousePosInBlocks, leftValue, rightValue);

        this.transform.position = paddlePos;
    }
}

编辑：抱歉，不是WorldToScreenPoint，ScreenToWorldPoint

Answer 2

尝试将paddlePos设置为您正在创建的新矢量（在世界空间中）：

public Texture texture; // if needed for something outside this code
private Vector3 paddlePos;
private float mousePosInBlocks;
private float xValue;
private float leftValue;
private float rightValue;

public void Update () {

    mousePosInBlocks = Camera.main.ScreenToWorldPoint(Input.mousePosition).x;
    //compute leftValue on this line
    //compute rightValue on this line

    xValue = Mathf.Clamp(mousePosInBlocks, leftValue, rightValue);

    paddlePos = new Vector3 (xValue, transform.position.y , 0f);

    transform.position = paddlePos;
}

编辑根据更新的问题标题，以下内容应该有效：

public Texture texture; // if needed for something outside this code
private Vector3 playerPosOnScreen;
private float mousePosInBlocks;

public void Update () {

    playerPosOnScreen = Camera.main.WorldToScreenPoint(transform.position);

    if (playerPosOnScreen.x > Screen.Width) {

        transform.position = Camera.main.ScreenToWorldPoint (new Vector3 (Screen.Width, transform.position.y, transform.position.z);

    } else if (playerPosOnScreen.x < 0f) {

        transform.position = Camera.main.ScreenToWorldPoint (new Vector3 (0f, transform.position.y, transform.position.z);

    }
}

Answer 3

尝试这样的事情:(伪代码，未经测试，给你一个想法）

请检查每个步骤的评论。

public void Update () {

        // left bound
        Vector3 left = Camera.main.ViewPortToScreenPoint(new Vector3(0f, 0f, 0f));

        // Menu width
        left.x += fmyMenuWidth; // Width of menu

        // Right bound
        Vector3 right= Camera.main.ViewPortToScreenPoint(new Vector3(1f, 1f, 0f));

        // Temporary position vector    
        Vector3 paddlePos = Vector3.zero;

        // capture mouse x
        float mouseX = Camera.main.ScreenToWorldPoint(Input.mousePosition).x;

        // capture mouse y
        float mouseY= Camera.main.ScreenToWorldPoint(Input.mousePosition).y;

        // Combine and limit the position's X-value, should not go off screen menu's width---->screen's width
        paddlePos.x = Mathf.Max(Mathf.Min(right.x, mouseX), left.x);

        // Combine and limit the position's Y-value, should not go off screen 0---->screen's height
        paddlePos.y = Mathf.Max(Mathf.Min(right.y, mouseY), left.y);

        // Finally set the bounded position
        this.transform.position = paddlePos;
}

如何使用数学方程来阻止物体离开屏幕？

3 个答案: