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Unity 2018.3 and Hololens: holograms are not stable

Discussion in 'Windows Mixed Reality' started by EdgarSantos, Mar 20, 2019.

  1. EdgarSantos

    EdgarSantos

    Joined:
    Nov 11, 2013
    Posts:
    12
    Hi.

    We've detected a quite serious issue with the 2018 releases of Unity (since 2018.2) with Hololens and hologram stability.

    Basically, the holograms are never stable. The best way to see the effect is to look at an hologram and physically jump a bit. The holograms also appear to jump instead of staying in place. Debugging the stabilization plane shows that the plane appears in the correct place but it seems to have no effect.

    Searching the internet, this issue seems to come up from time to time, but is mostly dismissed as not being unity's fault as most people use Mixed Reality Toolkit's implementation of stabilization plane.

    We've been "stuck" in Unity 2017.4 LTS because of this, since the issue doesn't happen in this version (currently 2017.4.23f1)
    We want to move on to Unity 2018.3, mostly because of the "nested prefabs" feature, latest Vuforia version, etc. But this issue keeps happening and it seems nothing is being done to fix it (not that I'm aware of). I hope this report changes this (I'm also writing a bug report).

    We created 2 empty unity projects (Unity 2017.4.23f1 and Unity 2018.3.9f1). In both projects we created a cube and a sphere that appear in front of the Hololens (fixed position). Both projects have the "Enable Depth Buffer Sharing" checked and some other basic settings to run in Hololens. No other mechanism is used (no world anchors, no MRT, no Vuforia tracking, no manual setting of stabilization plane, literally nothing else).
    After build/deploy, the final result of both projects can be compared and there's the obvious issue with the 2018.3 build.

    Unity 2017.4.23f1 (LTS): (holograms are stable)
    Unity2017.gif

    Unity 2018.3.9f1: (holograms are unstable)
    Unity2018.gif
    Actual framerate in both apps is constant 60fps.

    TLDR: Unity 2018.3 holograms are not stable. This doesn't happen in Unity 2017.4 LTS with the same settings. We're unable to update unity because of this and we really want/need to. It is most likely a Unity issue since no code or any other packages are being used.
     
    JasonCostanza likes this.
  2. JasonCostanza

    JasonCostanza

    Unity Technologies

    Joined:
    May 23, 2017
    Posts:
    295
    Hey @EdgarSantos I'd be happy to take a look at your bug. You're right most of our reports about unstable holograms are people using the MRTK. If you're reproducing this without MRTK at all then I am highly interested to hear about this. What is the bug number you submitted so I can pull it up on my end? I might have some follow up questions but I'll take a look at your repro projects first.

    Thanks
     
  3. EdgarSantos

    EdgarSantos

    Joined:
    Nov 11, 2013
    Posts:
    12
    Hi.

    The bug report has the 2 projects I mentioned in the post and the videos that show the issue (raw captured videos instead of compressed gifs).

    The info of the bug report:
    Case: 1138810
    Title: Unity 2018.3 and Hololens: holograms are not stable but they are in Unity 2017.4 LTS

    Thank you.
     
    JasonCostanza likes this.
  4. JasonCostanza

    JasonCostanza

    Unity Technologies

    Joined:
    May 23, 2017
    Posts:
    295
    Interesting... I'm trying to sync up to what you're seeing but my holograms are appearing very solid on 18.3.9f1. I've recorded a video to compare with you, would you say this is better, worse, or the same than what you are seeing?

    https://oc.unity3d.com/index.php/s/ERaNrD6ioLZORBG

    This is using your provided repro project. Thank you for those by the way, super helpful
     
  5. EdgarSantos

    EdgarSantos

    Joined:
    Nov 11, 2013
    Posts:
    12
    It actually looks like it's not so stable compared to what we get with 17.4LTS.

    Also, small up-down shifts while looking at the holograms is the best way to reproduce the issue we're having.
    (that's what I'm doing in the videos attached to the bug report, which are the sources for the gifs posted here).
     
  6. JasonCostanza

    JasonCostanza

    Unity Technologies

    Joined:
    May 23, 2017
    Posts:
    295
    I'll dig in to this more, these are notoriously difficult to track down from my experience with stabilization issues