Unity使用LineRender实现绘画功能

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

public class DrawLine_ZH : MonoBehaviour
{
 private GameObject _Clone;
 private LineRenderer _Line;
 int _Number;

 //带有LineRender物体
 [Header("LineRender预制体")]
 public GameObject _Target;

 void Update()
 {
  if (Input.GetMouseButtonDown(0))
  {
   //实例化对象
   _Clone = Instantiate(_Target, _Target.transform.position, Quaternion.identity);

   //获得该物体上的LineRender组件
   _Line = _Clone.GetComponent<LineRenderer>();

   //设置起始和结束的颜色
   //_Line.SetColors(Color.red, Color.blue);
   _Line.startColor = Color.red;
   _Line.endColor = Color.blue;

   //设置起始和结束的宽度
   // _Line.SetWidth(0.2f, 0.1f);
   _Line.startWidth = 0.2f; ;
   _Line.endWidth = 0.1f;

   //计数
   _Number = 0;
  }
  if (Input.GetMouseButton(0))
  {
   //每一帧检测，按下鼠标的时间越长，计数越多
   _Number++;

   //设置顶点数
   //_Line.SetVertexCount(_Number);
   _Line.positionCount = _Number;

   //设置顶点位置(顶点的索引，将鼠标点击的屏幕坐标转换为世界坐标)
   _Line.SetPosition(_Number - 1, Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, 15)));


  }

  //清除绘画

  if (Input.GetMouseButtonDown(1))
  {
   GameObject[] _Draw = GameObject.FindGameObjectsWithTag("DarwLine");
   for (int i = 0; i < _Draw.Length; i++)
   {
    Destroy(_Draw[i]);
   }
  }

 }
}