Creating a Marker Track & Markers that work without Track Binding

Is it possible to create a MarkerTrack that works without requiring a Track Binding? Let's call it EnemySpawnMarkerTrack

It would work alongside a custom Marker class EnemySpawnMarker. Ideally I would want some kind of method to be called in EnemySpawnMarker that is called when the timeline reaches the marker. There doesn't seem to be any such functionality in the existing API, so I imagine it would have to be implemented in some other way

I'm aware you can just place markers on the Markers section of the Timeline and that will automatically use the gameobject that the Director is on, but I specifically want to use Markers on a custom Marker Track

Markers seem to be designed to be used with INotification and INotificationReceiver, and I am familiar with how those work. but this requires a Track Binding

 

@seant_unity I've noticed that

CreateTrackMixer(..)

and

CreatePlayable(..)

on

TrackAsset

never actually gets called if the Track doesn't have any clips. On a Marker Track, obviously we won't have any clips in them. How should I get around this?

 

1) Don't want to use MonoBehaviour
2) Custom Marker Track with Custom Markers

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Playables;
3.  
4. class ReceiverExample : INotificationReceiver
5. {
6.  
7.     public void OnNotify(Playable origin, INotification notification, object context)
8.     {
9.         if (notification != null)
10.         {
11.             //double time = origin.IsValid() ? origin.GetTime() : 0.0;
12.             double time = ((SimpleMarker) notification).time;
13.             Debug.LogFormat("Received notification of type {0} at time {1}", notification.GetType(), time);
14.         }
15.     }
16. }

Code (CSharp):

1. using System.Collections.Generic;
2. using System.Linq;
3. using UnityEditor.Timeline;
4. using UnityEngine;
5. using UnityEngine.Playables;
6. using UnityEngine.Timeline;
7.  
8. #if UNITY_EDITOR
9.  
10. [CustomTimelineEditor(typeof(SignalTrackEx))]
11. public class FakeTrackEditor : TrackEditor
12. {
13.     public override void OnCreate(TrackAsset track, TrackAsset copiedFrom)
14.     {
15.         track.CreateCurves("FakeCurves");
16.         track.curves.SetCurve(string.Empty, typeof(GameObject), "m_FakeCurve", AnimationCurve.Linear(0, 1, 1, 1));
17.         base.OnCreate(track, copiedFrom);
18.     }
19. }
20.  
21. #endif
22.  
23.  
24. public class SignalTrackEx : MarkerTrack
25. {
26.  
27.  
28.  
29.     ReceiverExample m_Receiver;
30.  
31.     public override IEnumerable<PlayableBinding> outputs
32.     {
33.         get
34.         {
35.             var playableBinding = ScriptPlayableBinding.Create(name, null, typeof(GameObject));
36.  
37.  
38.             //return this == timelineAsset.markerTrack ? new List<PlayableBinding> {playableBinding} : base.outputs;
39.             // return base.outputs;
40.             return new List<PlayableBinding> {playableBinding};
41.         }
42.     }
43.  
44.  
45.  
46.     public override Playable CreateTrackMixer(PlayableGraph graph, GameObject go, int inputCount)
47.     {
48.        
49.        
50.         if (Application.isPlaying)
51.         {
52.             PlayableOutput playableOutput = graph.GetOutput(0);
53.  
54.             if (playableOutput.IsOutputValid())
55.             {
56.                 ScriptPlayable<TimeNotificationBehaviour> scriptPlayable =
57.                     (ScriptPlayable<TimeNotificationBehaviour>) playableOutput.GetSourcePlayable().GetInput(0);
58.  
59.              
60.  
61.                 TimeNotificationBehaviour timeNotificationBehaviour = scriptPlayable.GetBehaviour();
62.  
63.                 var simpleMarkers = this.GetMarkers().OfType<SimpleMarker>();
64.                
65.                 m_Receiver=new ReceiverExample();
66.  
67.                 playableOutput.AddNotificationReceiver(m_Receiver);
68.  
69.                 foreach (var marker in simpleMarkers)
70.                 {
71.                  
72.                     scriptPlayable.GetBehaviour().AddNotification(marker.time, marker);
73.                 }
74.             }
75.             else
76.             {
77.              
78.                 playableOutput = ScriptPlayableOutput.Create(graph, "NotificationOutput");
79.                
80.                  m_Receiver=new ReceiverExample();
81.                
82.                 //why also here and in "outputs"
83.                 playableOutput.AddNotificationReceiver(m_Receiver);
84.                
85.                 //Create a TimeNotificationBehaviour
86.                 var timeNotificationPlayable = ScriptPlayable<TimeNotificationBehaviour>.Create(graph);
87.                
88.                 playableOutput.SetSourcePlayable(graph.GetRootPlayable(0));
89.                 timeNotificationPlayable.GetBehaviour().timeSource = playableOutput.GetSourcePlayable();
90.                 playableOutput.GetSourcePlayable().SetInputCount(playableOutput.GetSourcePlayable().GetInputCount()+1);
91.                 graph.Connect(timeNotificationPlayable, 0, playableOutput.GetSourcePlayable(), playableOutput.GetSourcePlayable().GetInputCount()-1);
92.                
93.                 var simpleMarkers = this.GetMarkers().OfType<SimpleMarker>();
94.                
95.                
96.                 foreach (var marker in simpleMarkers)
97.                 {
98.                  
99.                     timeNotificationPlayable.GetBehaviour().AddNotification(marker.time, marker);
100.                 }
101.             }
102.         }
103.  
104.         return base.CreateTrackMixer(graph, go, inputCount);
105.      
106.     }
107.  
108. }

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.Playables;
3. using UnityEngine.Timeline;
4.  
5. public class SimpleMarker : Marker,INotification,INotificationOptionProvider
6. {
7.  
8.     [SerializeField] public bool emitOnce;
9.     [SerializeField] public bool emitInEditor;
10.    
11.  
12.  
13.     NotificationFlags INotificationOptionProvider.flags =>
14.         (emitOnce ? NotificationFlags.TriggerOnce : default) |
15.         (emitInEditor ? NotificationFlags.TriggerInEditMode : default);
16.  
17.     public PropertyName id { get; }
18. }
19.  

May the Forge be with you!

 

Don't use "0,1,1,1" in the fake curves, this will force the timeline to have a minimum duration of 1 seconds. Use "0,0,0,0", instead