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By Design



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Issue ID




Embedded Timeline Clips are not being played by the parent Timeline clip when entering the Play Mode

Package: Timeline


How to reproduce:
1. Open the "IN_33987" project
2. Open the "SampleScene"
3. Enter the Play Mode
4. Observe the Console

Expected result: info messages "First Track" and "Second Track" are thrown and both Timelines are played
Actual result: info message "First Track" is thrown and only one Timeline is played

Reproducible with: 1.4.8 (2020.3.47f1), 1.6.4 (2021.3.22f1), 1.7.4 (2022.2.14f1), 1.8.2 (2023.1.0b11, 2023.2.0a9)

Reproducible on: Windows 10 Pro

Note: also reproducible in the Player

  1. Resolution Note:

    The behaviour here is by design.

    The issue is occurring due to the Timeline Asset's Playable having a Passthrough traveral mode. We create all Timeline Asset Playables like this. With the kind of setup presented in this report there's an extra clip playable in between the two Timeline Playables. The 'child' timeline has two outputs that are passed through but the intermediary clip expects 1 input (EmbeddedTimelineClip's playable). It accepts the first output (which prints "First Track") but the second is ignored.

    A workaround is to manually set the Timelien Playable's traversal mode to Mix.

    public class EmbeddedTimelineClip : PlayableAsset
    [SerializeField] private TimelineAsset _timelineAsset;

    public override Playable CreatePlayable(PlayableGraph graph, GameObject owner)
    if (!_timelineAsset)
    return Playable.Null;

    Playable playable = _timelineAsset.CreatePlayable(graph, owner);

    return playable;

    I've discussed this with the reporter and it fixes their issue.

Comments (1)

  1. unity_892F320C6D26373D749A

    Apr 04, 2023 12:34


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