Unity中使用线渲染器时如何销毁线？

Question

所以我一次只想在屏幕上显示一行。当球碰撞或绘制另一条线时，我想破坏当前线。到目前为止，这是我的代码。它创建了一个带有两个点的线渲染器，添加了一个 Box 碰撞器。我试过做一个循环并将向量点设置回零。

每次我添加 OnCollisonEnter2D 时，我都无法让 Line 记录它击中了一个球。在 Ball 脚本中，当 Ball 撞到对撞机时，我可以让 Log 打印 Hit。

using System.Runtime.CompilerServices;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.UI;

public class Player1 : MonoBehaviour
{
    private LineRenderer line; // Reference to LineRenderer
    private Vector3 mousePos;
    public  Vector3 startPos;    // Start position of line
    public  Vector3 endPos;    // End position of line

    void Update()
    {
        GetLine(); // On mouse down new line will be created 
    }

    private void GetLine()
    {
        if (Input.GetMouseButtonDown(0))
        {
            if (line == null)
                CreateLine();
                SetFirstPos();
        }
        else if (Input.GetMouseButtonUp(0))
        {
            if (line)
            {
                SetSecondPos();
                AddColliderToLine();
                line = null;
            }
        }
        else if (Input.GetMouseButton(0))
        {
            if (line)
            {
                mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
                mousePos.z = 0;
                line.SetPosition(1, mousePos);
            }
        }
    }

    // Following method creates line runtime using Line Renderer component
    private void CreateLine()
    {
        line = new GameObject("Line").AddComponent<LineRenderer>();
        line.positionCount = 2;
        line.numCapVertices = 2;
        line.startWidth = .25f;
        line.endWidth = .25f;
        line.startColor = Color.black;
        line.endColor = Color.black;
        line.useWorldSpace = true;
    }
    // Following method adds collider to created line
    private void AddColliderToLine()
    {
        BoxCollider2D col = new GameObject("Collider").AddComponent<BoxCollider2D>();
        col.transform.parent = line.transform; // Collider is added as child object of line
        float lineLength = Vector3.Distance(startPos, endPos);// length of line
        lineLength.ToString();
        col.size = new Vector3(lineLength, 0.25f, 1f); // size of collider is set where X is length of 
        line, Y is width of line, Z will be set as per requirement
        Vector3 midPoint = (startPos + endPos) / 2;
        col.transform.position = midPoint; // setting position of collider object
        // Following lines calculate the angle between startPos and endPos
        float angle = (Mathf.Abs(startPos.y - endPos.y) / Mathf.Abs(startPos.x - endPos.x));
        if ((startPos.y < endPos.y && startPos.x > endPos.x) || (endPos.y < startPos.y && endPos.x > 
        startPos.x))
        {
            angle *= -1;
        }
        angle = Mathf.Rad2Deg * Mathf.Atan(angle);
        col.transform.Rotate(0, 0, angle);
    }
    //Sets the first position
    private void SetFirstPos()
    {
        mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        mousePos.z = 0;
        line.SetPosition(0, mousePos);
        startPos = mousePos;
        Debug.Log("Line");
    }
    //Sets the second position
    private void SetSecondPos()
    {
        mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        mousePos.z = 0;
        line.SetPosition(1, mousePos);
        endPos = mousePos;
    }
    //Cannot get it to Log Hit. Line show up in the Hierarchy.
    private void OnCollisionEnter2D(Collision2D collision)
    {
        if(collision.gameobject.name =="Line")
        {
            Debug.Log("Hit!");
        }
    }
}

Answer 1

如果您的OnCollisionEnter2D 被调用，为什么不使用就使用它？

private void OnCollisionEnter2D(Collision2D collision)
{
    if(collision.gameObject.name =="Line")
    {
        Debug.Log("Hit!");
        // destroy the hit line
        GameObject.Destroy(collision.gameObject);
    }
}

如果您希望在创建新行后销毁该行，则必须将其存储并手动销毁：

public class Player1 : MonoBehaviour
{
    private GameObject lastLine;
    [...]

    private void GetLine()
    {
        if (Input.GetMouseButtonDown(0))
        {
            if(lastLine != null)
            {
                GameObject.Destroy(lastLine);
            }
            if (line == null)
                CreateLine();
            SetFirstPos();
        }
        else if (Input.GetMouseButtonUp(0))
        {
            if (line)
            {
                SetSecondPos();
                AddColliderToLine();
                lastLine = line.gameObject;
                line = null;
            }
        }
        [...]
    }