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Can't edit timeline clip from code after exiting play mode

Discussion in 'Timeline' started by Solovykh, Sep 23, 2017.

  1. Solovykh

    Solovykh

    Joined:
    Aug 28, 2017
    Posts:
    18
    Hey guys,

    I made this simple example to show my problem. I create a timeline clip in code. And I'm able to edit its start time from the editor window just fine. However, as soon as I enter play, and then exit play mode. The link between my editor window start time and timeline clip is broken. What am I doing wrong?

    Code (CSharp):
    1. using UnityEditor;
    2. using UnityEngine;
    3. using UnityEngine.Playables;
    4. using UnityEngine.Timeline;
    5.  
    6. public class TimelineExample : EditorWindow
    7. {
    8.     public TimelineClip m_Clip;
    9.     private const float m_FPS = 30.0f;
    10.  
    11.  
    12.     [MenuItem("Window/TimelineExample")]
    13.     public static void ShowWindow()
    14.     {
    15.         GetWindow(typeof(TimelineExample));
    16.     }
    17.  
    18.     void Awake()
    19.     {
    20.         GameObject newObject = new GameObject();
    21.         PlayableDirector playableDirector = newObject.AddComponent<PlayableDirector>();
    22.         TimelineAsset timelineAsset = CreateInstance<TimelineAsset>();
    23.         timelineAsset.editorSettings.fps = m_FPS;
    24.         playableDirector.playableAsset = timelineAsset;
    25.         AssetDatabase.CreateAsset(timelineAsset, "Assets/timelineAsset.playable");
    26.         AnimationTrack track = timelineAsset.CreateTrack<AnimationTrack>(null, "testTrack");
    27.         m_Clip = track.CreateDefaultClip();
    28.     }
    29.  
    30.     void OnGUI()
    31.     {
    32.         int startFrame = (int)(m_Clip.start * m_FPS);
    33.         int newStartFrame;
    34.         if (int.TryParse(EditorGUILayout.TextField("Start Frame:", startFrame.ToString()), out newStartFrame))
    35.         {
    36.             m_Clip.start = newStartFrame / m_FPS;
    37.         }
    38.     }
    39.  
    40.  
    41.  
    42. }
    43.  
     
  2. seant_unity

    seant_unity

    Unity Technologies

    Joined:
    Aug 25, 2015
    Posts:
    917
    TimelineClip does not inherit from UnityEngine.Object, but it is serializable.

    So if the window reserializes, it will create a clone of the clip. The same thing will happen if the timeline reloads/reserializes - the clip in your window will no longer be referencing a valid clip.

    The simplest solution is probably to reassign your clip in OnEnable().
     
  3. Solovykh

    Solovykh

    Joined:
    Aug 28, 2017
    Posts:
    18
    Hey Sean, thanks for response.

    Does this mean that in order to keep track of a timeline clip, I have to do something like this in OnEnable everytime? Seems tedious.

    Code (CSharp):
    1. var tracks = timelineAsset.GetOutputTracks();
    2. foreach (var track in tracks)
    3. {
    4.        foreach (var timelineClip in track.GetClips())
    5.        {
    6.            if (timelineClip.displayName == m_Clip.displayName) m_Clip = timelineClip;
    7.        }
    8. }