Search Unity

  1. Welcome to the Unity Forums! Please take the time to read our Code of Conduct to familiarize yourself with the forum rules and how to post constructively.
  2. We have updated the language to the Editor Terms based on feedback from our employees and community. Learn more.
    Dismiss Notice

Timeline Control Track's Random Seed

Discussion in 'Timeline' started by h-duong, Apr 23, 2018.

  1. h-duong


    Jan 15, 2018

    Right now I'm working on effects using version 2017.3.1p4's timeline.
    And I'm having problem with the control track playable asset clip's random seed.

    Before when I used version 2017.1.2f1, this random seed didn't seem to actually do anything,
    but right now it's affecting all the particle system's random seeds and forcing them to be the same value.
    This is really troublesome when I want to use different seeds on different emitters or when I want to use auto random seed.

    Is the control track's random seed actually needed? Like because if we want to use random seed we can just set them ourselves on each emitter.
    If it's possible then can I ask for a way to remove this? controltrackrandomseed.JPG
  2. seant_unity


    Unity Technologies

    Aug 25, 2015
    The random seed is set to make preview and playback match exactly, in particularly when scrubbing - Timeline needs to resimulate when scrubbing backwards.

    The only way around that is to uncheck 'Control Particle Systems', and let the particle systems play on awake (which will disable preview). The consequence of that will be the synchronization with the timeline may be off by up to a frame, which may be a completely acceptable tradeoff, depending on the situation.
  3. h-duong


    Jan 15, 2018
    Thanks for the reply, seant.

    Ok so I got the reason why the random seed was needed for the control track.
    But then the thing is why the control track in 2017.3.1p4 works different compare to 2017.1.2f1?
    I mean in 2017.1.2f1 it didn't affect the particle system's random seed but still was able to preview normally.
  4. PeachyPixels


    Feb 17, 2018
    Hi Everyone,

    I've been hitting what I think is this issue as well using Unity 2020.3.14f1

    I have a particle system prefab with Auto Random Seed enabled.

    When I play the timeline in scene view, the prefab Auto Random Seed is disabled and updated with the fixed seed from the playable. Very annoying as I have to keep reverting it.

    I believe this was fixed in 2019.1 as shown here...

    So is this a regression or a separate issue?
    Last edited: Aug 11, 2021
  5. Danielsantalla


    Jan 7, 2015
    Could we have a button to simply disable the auto seed? there are many cases where I simply don't want an auto seed