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Placing Holograms at predefined locations in Spatial Mapping (Hololens)

DustinKDustinK
edited June 2018 in Questions And Answers

Hello everyone,
I am trying to develop a small Hololens app, where specific objects need to be placed at predefined locations within a room. The room is already scanned by the Hololens and I have a detailed spatial map. I know how to place Holograms by User Input and reload them, but is it possible to somehow place Objects at certain positions during development? I imagine the different starting point of the user would be a problem. I've read something about using Spatial Anchors, but do not understand the concept well enough. Could someone explain?
I am using Unity to develope the app.

Regards,
Dustin

Answers

  • Hey Dustin, It sounds like Spatial Anchors is exactly what you need. Basically Spatial Anchors save an objects exact position in space. So if you want certain objects to be in a certain spot then you will need to assign it a spatial anchor so it will always be in the same location (even if the Hololens is shut down and turn back on).

    test that helped fully understand it was. I had a detailed spatial map of my office and a 3D model of a Globe. I applied a spatial anchor to the 3d Globe and placed it on top of my keyboard. So now that every time my spatial map of my office is opened the 3D globe is always on my keyboard.

    May i recommend you check out this blog. It really helped me out.

    https://mtaulty.com/2016/12/20/hitchhiking-the-holotoolkity-unity-leg-5-baby-steps-with-world-anchors-and-persisting-holograms/

  • stepan_stulovstepan_stulov ✭✭✭
    edited June 2018

    Hey, @DustinK

    I know how to place Holograms by User Input and reload them, but is it possible to somehow place Objects at certain positions during development?

    To my knowledge spatial (world) anchors are a runtime-only concept. They don't exist outside of a HoloLens application. There is no way to author them on your desktop. This means you can go these two ways:

    1. You can create either a separate restricted access positioning mode or a separate positioning application that would produce anchors that the user will then not be allowed to move. In case of a separate mode you can roll with WorldAnchorStore and in both cases you can roll with WorldAnchorTransferBatch.
    2. You can position your points on your desktop at design (a.k.a. development) time relative to some pivot/wireframe. That wireframe can be based ona CAD file of your shop floor, on a spatial mapping mesh or on your living room plan etc. Then you still have to position the entire wireframe from within the app. This approach has limitations such as the further your points are from the pivot the less stable they are due to leverage effect.

    You can also combine these approaches in some way. But ultimately there is no way to produce a world anchor from anywhere outside a running HoloLens app.

    Also check this thread:
    https://forums.hololens.com/discussion/comment/22116

    There are some third party anchoring mechanisms such as marker-based Vuforia, seemingly platform-independent marker-less (and not yet released I think) YouAR anchors. These last guys claimed to be able to even re-use anchors produced on a non-Hololens device back on HoloLens. Perhaps they know the anchors serialization format which to my knowledge is not open. I'm yet to test it.

    Cheers

    Building the future of holographic navigation. We're hiring.

  • Thank you very much for your help guys, I will place the Holograms by hand then and remove placing abilities for other users after that! Thanks again!

  • Thank you very much for your help guys, I will place the Holograms by hand then and remove placing abilities for other users after that! Thanks again!

  • Hi @DustinK and all,
    I hope that I can contribute to this conversation by adding one more idea...:)
    I've recently managed to use Vuforia AR SDK together with MRTK SDK... that means can anchor holograms relative to an Image/Object/... targets (real physical targets),
    And by that force hologram to stay put.
    Also, I think/wish that this particular ability will be in Unty3D MARS project... according to some presentations at Berlin 18...

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