File is updated with TrackAsset.muted

There is no specific runtime mute feature, although that has been requested. One (inefficient) way to accomplish it is to mute the track, then call playableDirector.RebuildGraph().

A more complicated, but efficient method you can try is removing the binding from the playable graph. This only works if the track is bound to an object (so it wouldn't work for control tracks).

There are separate code paths for Animation, Scripts (i.e. custom) and Audio needed. But removing the binding on Audio won't work because unbound audio tracks still play (just without a 3D source).

For script tracks, they will still run and require that the custom script track properly handles a null passed into the userdata field in ProcessFrame();

Code (CSharp):

1.        static void MuteAnimTrack(PlayableDirector director, Animator animator)
2.         {
3.             if (director == null || !director.playableGraph.IsValid())
4.                 return;
5.  
6.             for (int i = 0; i < director.playableGraph.GetOutputCountByType<AnimationPlayableOutput>(); i++)
7.             {
8.                 var animOutput = (AnimationPlayableOutput) director.playableGraph.GetOutputByType<AnimationPlayableOutput>(i);
9.                 var binding = animOutput.GetTarget();
10.                 if (binding == animator)
11.                     animOutput.SetTarget(null);
12.             }
13.         }
14.  
15.         static void MuteScriptTrack(PlayableDirector director, UnityEngine.Object target)
16.         {
17.             if (director == null || !director.playableGraph.IsValid())
18.                 return;
19.  
20.             for (int i = 0; i < director.playableGraph.GetOutputCountByType<ScriptPlayableOutput>(); i++)
21.             {
22.                 var scriptOutput = (ScriptPlayableOutput) director.playableGraph.GetOutputByType<ScriptPlayableOutput>(i);
23.                 var binding = scriptOutput.GetUserData();
24.                 if (binding == target)
25.                     scriptOutput.SetUserData(binding);
26.             }
27.         }
28.