Unity实现VR中在黑板上写字效果

using System.Linq;using UnityEngine;/// <summary>/// 画板/// </summary>public class Board : MonoBehaviour{ //当画笔移动速度很快时，为了不出现断断续续的点，所以需要对两个点之间进行插值，lerp就是插值系数 [Range(0, 1)] public float lerp = 0.05f; //初始化背景的图片 public Texture2D initailizeTexture; //当前背景的图片 private Texture2D currentTexture; //画笔所在位置映射到画板图片的UV坐标 private Vector2 paintPos; private bool isDrawing = false;//当前画笔是不是正在画板上 //离开时画笔所在的位置  private int lastPaintX; private int lastPaintY; //画笔所代表的色块的大小 private int painterTipsWidth = 30; private int painterTipsHeight = 15; //当前画板的背景图片的尺寸 private int textureWidth; private int textureHeight; //画笔的颜色 private Color32[] painterColor; private Color32[] currentColor; private Color32[] originColor; private void Start() { //获取原始图片的大小  Texture2D originTexture = GetComponent<MeshRenderer>().material.mainTexture as Texture2D; textureWidth = originTexture.width;//1920  textureHeight = originTexture.height;//1080 //设置当前图片 currentTexture = new Texture2D(textureWidth, textureHeight, TextureFormat.RGBA32, false, true); currentTexture.SetPixels32(originTexture.GetPixels32()); currentTexture.Apply(); //赋值给黑板 GetComponent<MeshRenderer>().material.mainTexture = currentTexture; //初始化画笔的颜色 painterColor = Enumerable.Repeat<Color32>(new Color32(255, 0, 0, 255), painterTipsWidth * painterTipsHeight).ToArray<Color32>(); } private void LateUpdate() { //计算当前画笔，所代表的色块的一个起始点 int texPosX = (int)(paintPos.x * (float)textureWidth - (float)(painterTipsWidth / 2)); int texPosY = (int)(paintPos.y * (float)textureHeight - (float)(painterTipsHeight / 2)); if (isDrawing) {  //改变画笔所在的块的像素值  currentTexture.SetPixels32(texPosX, texPosY, painterTipsWidth, painterTipsHeight, painterColor);  //如果快速移动画笔的话，会出现断续的现象，所以要插值  if (lastPaintX != 0 && lastPaintY != 0)  {  int lerpCount = (int)(1 / lerp);  for (int i = 0; i <= lerpCount; i++)  {   int x = (int)Mathf.Lerp((float)lastPaintX, (float)texPosX, lerp);   int y = (int)Mathf.Lerp((float)lastPaintY, (float)texPosY, lerp);   currentTexture.SetPixels32(x, y, painterTipsWidth, painterTipsHeight, painterColor);  }  }  currentTexture.Apply();  lastPaintX = texPosX;  lastPaintY = texPosY; } else {  lastPaintX = lastPaintY = 0; } } /// <summary> /// 设置当前画笔所在的UV位置 /// </summary> /// <param name="x"></param> /// <param name="y"></param> public void SetPainterPositon(float x, float y) { paintPos.Set(x, y); } /// <summary> /// 画笔当前是不是在画画 /// </summary> public bool IsDrawing { get {  return isDrawing; } set {  isDrawing = value; } } /// <summary> /// 使用当前正在画板上的画笔的颜色 /// </summary> /// <param name="color"></param> public void SetPainterColor(Color32 color) { if (!painterColor[0].IsEqual(color)) {  for (int i = 0; i < painterColor.Length; i++)  {  painterColor[i] = color;  } } }}public static class MethodExtention{ /// <summary> /// 用于比较两个Color32类型是不是同种颜色 /// </summary> /// <param name="origin"></param> /// <param name="compare"></param> /// <returns></returns> public static bool IsEqual(this Color32 origin, Color32 compare) { if (origin.g == compare.g && origin.r == compare.r) {  if (origin.a == compare.a && origin.b == compare.b)  {  return true;  } } return false; }}

using UnityEngine;public class Painter : MonoBehaviour{ /// <summary> /// 画笔的颜色 /// </summary> public Color32 penColor; public Transform rayOrigin; private RaycastHit hitInfo; //这个画笔是不是正在被手柄抓着 private bool IsGrabbing; private static Board board;//设置成类型的成员，而不是类型实例的成员，因为所有画笔都是用的同一个board private void Start() { //将画笔部件设置为画笔的颜色，用于识别这个画笔的颜色 foreach (var renderer in GetComponentsInChildren<MeshRenderer>()) {  if (renderer.transform == transform)  {  continue;  }  renderer.material.color = penColor; } if (!board) {  board = FindObjectOfType<Board>(); }  } private void Update() { Ray r = new Ray(rayOrigin.position, rayOrigin.forward); if (Physics.Raycast(r, out hitInfo, 0.1f)) {  if (hitInfo.collider.tag == "Board")  {  //设置画笔所在位置对应画板图片的UV坐标   board.SetPainterPositon(hitInfo.textureCoord.x, hitInfo.textureCoord.y);  //当前笔的颜色  board.SetPainterColor(penColor);  board.IsDrawing = true;  IsGrabbing = true;  } } else if(IsGrabbing) {  board.IsDrawing = false;  IsGrabbing = false; } }}