Unity 编辑器下控制播放粒子

在Unity编辑器的Scene视图进行控制播放粒子ParticleSystem，可以借助方法Simulate，具体可以参照以下例子：

创建一个空对象ParticleAll，在这个对象下添加一个粒子（要添加多个粒子的话，添加到这个粒子之下），此时选中粒子， 可以看到 Scene视图预览播放粒子效果。附上新脚本 EditParticleSystem ，此为空脚本，如下：

using UnityEngine;

public  class EditParticleSystem : MonoBehaviour
{
}

创建一个这个脚本的编辑器类 EditParticleSystemInspector，代码如下：

using UnityEditor;
using UnityEngine;

[CustomEditor( typeof(EditParticleSystem))]
public  class EditParticleSystemInspector : Editor
{
     /// <summary>
     /// 滑动杆的当前时间
     /// </summary>
     private  float m_CurTime;
    
     /// <summary>
     /// 当前是否是预览播放状态
     /// </summary>
     private  bool m_Playing;

     /// <summary>
     /// 当前运行时间
     /// </summary>
     private  float m_RunningTime;
    
     /// <summary>
     /// 上一次系统时间
     /// </summary>
     private  double m_PreviousTime;

     /// <summary>
     /// 滑动杆总长度
     /// </summary>
     private  const  float kDuration = 30f;

     private ParticleSystem m_ParticleSystem;

     private EditParticleSystem editAnimator { get {  return target  as EditParticleSystem; } }

     private ParticleSystem particleSystem
    {
        get {  return m_ParticleSystem ?? (m_ParticleSystem = editAnimator.GetComponentInChildren<ParticleSystem>()); }
    }

     void OnEnable()
    {
        m_PreviousTime = EditorApplication.timeSinceStartup;
        EditorApplication.update += inspectorUpdate;
    }

     void OnDisable()
    {
        EditorApplication.update -= inspectorUpdate;
    }

     public  override  void OnInspectorGUI()
    {
        EditorGUILayout.BeginHorizontal();
         if (GUILayout.Button( "Play"))
        {
            play();
        }
         if (GUILayout.Button( "Stop"))
        {
            stop();
        }
        EditorGUILayout.EndHorizontal();
        m_CurTime = EditorGUILayout.Slider( "Time:", m_CurTime, 0f, kDuration);
        manualUpdate();
    }

     /// <summary>
     /// 进行预览播放
     /// </summary>
     private  void play()
    {
         if (Application.isPlaying || particleSystem ==  null)
        {
             return;
        }

        m_RunningTime = 0f;
        m_Playing =  true;
    }

     /// <summary>
     /// 停止预览播放
     /// </summary>
     private  void stop()
    {
         if (Application.isPlaying || particleSystem ==  null)
        {
             return;
        }

        m_Playing =  false;
        m_CurTime = 0f;
    }

     /// <summary>
     /// 预览播放状态下的更新
     /// </summary>
     private  void update()
    {
         if (Application.isPlaying || particleSystem ==  null)
        {
             return;
        }

         if (m_RunningTime >= kDuration)
        {
            m_Playing =  false;
             return;
        }

        particleSystem.Simulate(m_RunningTime,  true);
        SceneView.RepaintAll();
        Repaint();

        m_CurTime = m_RunningTime;
    }

     /// <summary>
     /// 非预览播放状态下，通过滑杆来播放当前动画帧
     /// </summary>
     private  void manualUpdate()
    {
         if (particleSystem && !m_Playing)
        {
            particleSystem.Simulate(m_CurTime,  true);
            SceneView.RepaintAll();
        }
    }

     private  void inspectorUpdate()
    {
        var delta = EditorApplication.timeSinceStartup - m_PreviousTime;
        m_PreviousTime = EditorApplication.timeSinceStartup;

         if (!Application.isPlaying && m_Playing)
        {
            m_RunningTime = Mathf.Clamp(m_RunningTime + ( float)delta, 0f, kDuration);
            update();
        }
    }
}

检视器效果如下：

\

拖动滑杆，即可播放当前时间的那一帧，如下所示：\

\

点击" Play"，即可以自动播放整个粒子，如下所示：