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How to view Child of entity

Discussion in 'Entity Component System' started by Soaryn, Sep 7, 2018.

  1. Soaryn

    Soaryn

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    So far I have found a method of viewing the parent entity, but seemingly no easy way of viewing an array of child entities. Do I need to compose that myself every frame, or is there some handler for that, that exists.


    Case scenario, I want to destroy a root entity that has 1 child node, that has multiple children nodes.

    When destroying said root, unity crashes, and if I want to further process the children I would like some way to grab an array of said children.
     
    Soaryn, Sep 7, 2018
    #1

  2. Joachim_Ante

    Joachim_Ante

    Unity Technologies

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    As a starting point. Unity shouldn't crash. Can you make a repro case so we can fix it?
     
    Joachim_Ante, Sep 7, 2018
    #2

  3. Joachim_Ante

    Joachim_Ante

    Unity Technologies

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    We currently don't have an API to grab children. We definately agree the there should be concepts of sets / hierarchies that automatically perform destruction similar to how it works with game objects. We currently don't have that, but it's something we are discussing on how to do exactly in an efficient way.
     
    Joachim_Ante, Sep 7, 2018
    #3
    Shinyclef, Vacummus and optimise like this.

  4. Soaryn

    Soaryn

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    Okey dokey. I will make a repo soon. Currently streaming some silliness. For now, I'll use spare time to fiddle around with an entity child tracker... which sounds terrible if said aloud.
     
    Soaryn, Sep 7, 2018
    #4

  5. Soaryn

    Soaryn

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    @Joachim_Ante This should be enough. https://github.com/Soaryn/Demo-Unity-ECS-ParentDestroy
    The 'delete' key will attempt to destroy the "root" entity (the center cube). Once done the resulting orphaned nodes revolt.
     
    Soaryn, Sep 14, 2018
    #5

  6. WAYNGames

    WAYNGames

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    Hi @Joachim_Ante, Sorry to dig that one up but I don't think it has been solved in the DOTS stack realesed since then.
     
    WAYNGames, Jun 14, 2019
    #6

  7. Sarkahn

    Sarkahn

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    Any parent/child hierarchy set up with the ConvertToEntity workflow will have a Child DynamicBuffer to access children from the parent. You can add LinkedEntityGroup (ConversionSystem.AddLinkedEntityGroup) to have expected insantiation/deletion behaviour on parent entities.
     
    Last edited: Jun 14, 2019
    Sarkahn, Jun 14, 2019
    #7
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  8. WAYNGames

    WAYNGames

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    Great Tahnks !
     
    WAYNGames, Jun 14, 2019
    #8

  9. DogF

    DogF

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    How can we do this?
     
    DogF, Feb 8, 2021
    #9
    BeerCanAI likes this.