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Timeline Control Track's Random Seed

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

  1. h-duong

    h-duong

    Joined:
    Jan 15, 2018
    Posts:
    2
    Hello,

    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

    seant_unity

    Unity Technologies

    Joined:
    Aug 25, 2015
    Posts:
    1,516
    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

    h-duong

    Joined:
    Jan 15, 2018
    Posts:
    2
    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

    PeachyPixels

    Joined:
    Feb 17, 2018
    Posts:
    713
    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...

    https://issuetracker.unity3d.com/is...he-same-value-for-all-nested-particle-systems

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

    Danielsantalla

    Joined:
    Jan 7, 2015
    Posts:
    75
    Could we have a button to simply disable the auto seed? there are many cases where I simply don't want an auto seed