Unity编辑器 - 编辑器控制特效播放

编辑器控制特效播放

Unity的动画编辑器不能预览粒子系统的播放，为了方便预览特效，设想制作一个预览特效的工具，通常一个特效有三种组件：
- Animation
- Animator
- ParticleSystem

其中Unity编辑器在编辑器模式下会控制粒子的播放，所以这里控制特效播放的功能只能在播放模式下使用。

代码

using UnityEngine;
using UnityEditor;
using System;

public class EffctPlayBackWin : EditorWindow {
    [MenuItem("Tools/EffctPlayBack")]
    static void DoIt() {
        GetWindow<EffctPlayBackWin>();
    }

    private Transform _root;
    private ParticleSystem[] _particles;
    private Animation[] _animations;
    private Animator[] _animators;
    private float _time;
    private int frameCount = 5 * 60 + 1;

    private Rect _rect = new Rect(5, 5, 300, 600);

    private void OnGUI() {
        EditorGUIUtility.labelWidth = 60f;
        GUILayout.BeginArea(_rect);
        {
            //get those components from root transform
            EditorGUI.BeginChangeCheck();
            _root = EditorGUILayout.ObjectField("root:", _root, typeof(Transform), true) as Transform;
            if (EditorGUI.EndChangeCheck()) {
                FindComponets();
            }

            //use slider to control Animation,Animator and a ParticleSystem playback
            EditorGUI.BeginChangeCheck();
            _time = EditorGUILayout.Slider("Time:", _time, 0, 5);
            if (EditorGUI.EndChangeCheck()) {
                PlayBackAnimation();
                PlayBackAnimator();
                PlayBackParticle();
            }

            GUILayout.Space(10);
        }
        GUILayout.EndArea();
        EditorGUIUtility.labelWidth = 0f;
    }

    private void PlayBackParticle() {
        if (_particles != null) {
            foreach (var psys in _particles) {
                //need to close the random seed to control  ParticleSystem playback
                psys.useAutoRandomSeed = false;
                // Simulate the ParticleSystem to the time
                psys.Simulate(_time);
            }
        }
    }

    private void PlayBackAnimation() {
        if (_animations != null) {
            foreach (var animation in _animations) {
                if (animation.clip) {
                    var state = animation[animation.clip.name];
                    if (state) {
                        animation.Play(state.name);
                        state.time = _time;
                        state.speed = 0f;
                    }
                }
            }
        }
    }

    private void PlayBackAnimator() {
        if (_animators == null)
            return;
        foreach (var at in _animators) {
            at.playbackTime = _time;
            at.Update(0);
        }
    }

    private void FindComponets() {
        if (_root) {
            _animations = _root.GetComponentsInChildren<Animation>();
            _animators = _root.GetComponentsInChildren<Animator>();
            _particles = _root.GetComponentsInChildren<ParticleSystem>();

            //Bake Animator's animation to the buffer
            if (_animators != null) {
                foreach (var at in _animators) {
                    at.Rebind();
                    at.StopPlayback();
                    at.recorderStartTime = 0f;
                    at.StartRecording(frameCount);//will the recorded frames
                    for (int i = 1; i <= frameCount; i++) {
                        //recording every frame with delta time
                        at.Update(1.0f / 60);
                    }
                    //stop record and start playback
                    at.StopRecording();
                    at.StartPlayback();
                    at.playbackTime = 0f;
                    at.Update(0);
                }
            }
        }
    }
}