Hello everyone.

We have decided to phase out the Mixed Reality Forums over the next few months in favor of other ways to connect with us.

The first way we want to connect with you is our mixed reality developer program, which you can sign up for at https://aka.ms/IWantMR.

The plan between now and the beginning of May is to clean up old, unanswered questions that are no longer relevant. The forums will remain open and usable.

On May 1st we will be locking the forums to new posts and replies. They will remain available for another three months for the purposes of searching them, and then they will be closed altogether on August 1st.

So, where does that leave our awesome community to ask questions? Well, there are a few places we want to engage with you. For technical questions, please use Stack Overflow, and tag your questions using either hololens or windows-mixed-reality. If you want to join in discussions, please do so in the HoloDevelopers Slack, which you can join by going to https://aka.ms/holodevelopers. And always feel free to hit us up on Twitter @MxdRealityDev.

Does the Spatial Anchor stores the data Locally or in server ??

edited September 2018 in Questions And Answers

Wanted to scan the room in advance. and people using my app need not scan for load and track hololens.

this is scenario.
1. Opening the app
2. save the spatial mapping data of room.
3. make hologram scene with mapping data in unity editor.
4. my app has the data (at local or server).
5. another hololens download my app.
6. another hololens load the spatial mapping data of room. hologram scene I made also loaded in the room.

question:
Does the Spatial Anchor stores the data Locally or in server ??

Answers

  • Hi,

    It probably depends on what you're trying to achieve here and what you mean by 'scan the room'.

    If you switch a HoloLens on in an environment then it is going to continuously scan that environment and build its picture of what that environment looks like. A second device is going to do the same.

    As far as I know, there is no way to stop a HoloLens doing this & there is no way to tell a HoloLens "don't worry about scanning this space, it's already been done by another device so just load up some data from that other device".

    So I think that if this is what you mean by "scan the room" then I don't know of how you go about this.

    But, let's say that 'scanning the room' means that the user of device 1 is asked to mark out all the positions of the corners of the room where the walls meet the ceiling/floor. Let's imagine the room is rectangular so now you have 8 points in space where you can draw holograms (markers).

    You can save those positions somewhere (e.g. a cloud service).

    Now, when the second device comes along to that same room, you could load those 8 positions and draw the holograms. That user doesn't need to 'scan' in the same way as the first user.

    But, there's a problem. The co-ordinates from the 1st device will be relative to the co-ordinate system that the first device used in the room which will almost certainly not be the same as the second device.

    So, you need to establish a common reference point for all the co-ordinates to make sense across the devices and/or the instances of the application running on a single device.

    There are different ways of doing this.

    One example - you can use a marker in the room which establishes a known point & a known orientation & then take all your co-ordinates relative to that. you could automatically or manually locate that marker for the user.

    Another example - you can use 'spatial anchors' - this is effectively a 'marker' that the HoloLens can create based on what it sees in the room. In our example, you might use one anchor and then record the 8 co-ordinates relative to that. Or, you might record one anchor for each co-ordinate. There is guidance around when and where to create these things. Either way, if the device can create & export anchors so that they can be stored somewhere (e.g. cloud) then another device can access those anchors and attempt to re-establish them in the same space (although this can fail & you'd have to think about what to do in that circumstance) and use the relative co-ordinates to reconstruct the holograms in the right place.

    That's a long (too long?) explanation - does it help at all and, if not, can you give me more of an explanation as to what you're trying to do around 'scanning'?

Sign In or Register to comment.