Unity实现粒子光效导出成png序列帧

using UnityEngine;using UnityEditor;using System;using System.IO;using System.Collections;using System.Collections.Generic; public class ParticleExporter : MonoBehaviour{ // Default folder name where you want the animations to be output public string folder = "PNG_Animations";  // Framerate at which you want to play the animation public int frameRate = 25;     // export frame rate 导出帧率，设置Time.captureFramerate会忽略真实时间，直接使用此帧率 public float frameCount = 100;    // export frame count 导出帧的数目，100帧则相当于导出5秒钟的光效时间。由于导出每一帧的时间很长，所以导出时间会远远长于直观的光效播放时间 public int screenWidth = 960;    // not use 暂时没用，希望可以直接设置屏幕的大小（即光效画布的大小） public int screenHeight = 640; public Vector3 cameraPosition = Vector3.zero; public Vector3 cameraRotation = Vector3.zero;  private string realFolder = ""; // real folder where the output files will be private float originaltimescaleTime; // track the original time scale so we can freeze the animation between frames private float currentTime = 0; private bool over = false; private int currentIndex = 0; private Camera exportCamera; // camera for export 导出光效的摄像机，使用RenderTexture  public void Start() {  // set frame rate  Time.captureFramerate = frameRate;   // Create a folder that doesn't exist yet. Append number if necessary.  realFolder = Path.Combine(folder, name);   // Create the folder  if (!Directory.Exists(realFolder)) {   Directory.CreateDirectory(realFolder);  }   originaltimescaleTime = Time.timeScale;   GameObject goCamera = Camera.main.gameObject;  if (cameraPosition != Vector3.zero) {   goCamera.transform.position = cameraPosition;  }   if (cameraRotation != Vector3.zero) {   goCamera.transform.rotation = Quaternion.Euler(cameraRotation);  }   GameObject go = Instantiate(goCamera) as GameObject;  exportCamera = go.GetComponent<Camera>();   currentTime = 0;    }  void Update() {  currentTime += Time.deltaTime;  if (!over && currentIndex >= frameCount) {   over = true;   Cleanup();   Debug.Log("Finish");   return;  }   // 每帧截屏  StartCoroutine(CaptureFrame()); }  void Cleanup() {  DestroyImmediate(exportCamera);  DestroyImmediate(gameObject); }  IEnumerator CaptureFrame() {  // Stop time  Time.timeScale = 0;  // Yield to next frame and then start the rendering  // this is important, otherwise will have error  yield return new WaitForEndOfFrame();   string filename = String.Format("{0}/{1:D04}.png", realFolder, ++currentIndex);  Debug.Log(filename);   int width = Screen.width;  int height = Screen.height;   //Initialize and render textures  RenderTexture blackCamRenderTexture = new RenderTexture(width, height, 24, RenderTextureFormat.ARGB32);  RenderTexture whiteCamRenderTexture = new RenderTexture(width, height, 24, RenderTextureFormat.ARGB32);   exportCamera.targetTexture = blackCamRenderTexture;  exportCamera.backgroundColor = Color.black;  exportCamera.Render();  RenderTexture.active = blackCamRenderTexture;  Texture2D texb = GetTex2D();   //Now do it for Alpha Camera  exportCamera.targetTexture = whiteCamRenderTexture;  exportCamera.backgroundColor = Color.white;  exportCamera.Render();  RenderTexture.active = whiteCamRenderTexture;  Texture2D texw = GetTex2D();   // If we have both textures then create final output texture  if (texw && texb) {   Texture2D outputtex = new Texture2D(width, height, TextureFormat.ARGB32, false);    // we need to check alpha ourselves,because particle use additive shader   // Create Alpha from the difference between black and white camera renders   for (int y = 0; y < outputtex.height; ++y) { // each row    for (int x = 0; x < outputtex.width; ++x) { // each column     float alpha;     alpha = texw.GetPixel(x, y).r - texb.GetPixel(x, y).r;     alpha = 1.0f - alpha;     Color color;     if (alpha == 0) {      color = Color.clear;     } else {      color = texb.GetPixel(x, y);     }     color.a = alpha;     outputtex.SetPixel(x, y, color);    }   }     // Encode the resulting output texture to a byte array then write to the file   byte[] pngShot = outputtex.EncodeToPNG();   File.WriteAllBytes(filename, pngShot);    // cleanup, otherwise will memory leak   pngShot = null;   RenderTexture.active = null;   DestroyImmediate(outputtex);   outputtex = null;   DestroyImmediate(blackCamRenderTexture);   blackCamRenderTexture = null;   DestroyImmediate(whiteCamRenderTexture);   whiteCamRenderTexture = null;   DestroyImmediate(texb);   texb = null;   DestroyImmediate(texw);   texb = null;    System.GC.Collect();    // Reset the time scale, then move on to the next frame.   Time.timeScale = originaltimescaleTime;  } }  // Get the texture from the screen, render all or only half of the camera private Texture2D GetTex2D() {  // Create a texture the size of the screen, RGB24 format  int width = Screen.width;  int height = Screen.height;  Texture2D tex = new Texture2D(width, height, TextureFormat.ARGB32, false);  // Read screen contents into the texture  tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);  tex.Apply();  return tex; }}