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Question How many Vive wands simultaneously

Discussion in 'XR Interaction Toolkit and Input' started by Anthony_Aliad, Jan 24, 2023.

  1. Anthony_Aliad

    Anthony_Aliad

    Joined:
    Jan 24, 2023
    Posts:
    2
    Hi all

    Please accept my apologies in advance in case this has already been discussed but I could not find a comprehensive answer despite a couple of hours of research.

    We are currently designing an experience that we will be projected in a large room (5m radius) through blended projection over 8 projectors. We want the users to be able to interact (mostly point & clic + ideally drag and drop) remotely. One potential solution we imagined is to use vive wands + 4 base stations 2.0

    The target would be to enable up to 30 controllers in this experience.

    It is unclear wether it is feasible hardware wise (bluetooth emission limitations ? others ?) and if this even could be integrated through the XR toolkit.

    I only found this "old" 2019 post mentioning a setup working ok with up to 10 trackers:
    https://forum.htc.com/topic/7613-maximum-number-of-vive-trackers-2019-with-a-single-pc/

    Therefore if any of you has some experience or thoughts on that topic, we would be super interested!

    Thanks !
     
    Anthony_Aliad, Jan 24, 2023
    #1

  2. VRDave_Unity

    VRDave_Unity

    Unity Technologies

    Joined:
    Nov 19, 2021
    Posts:
    257
    Hey @Anthony_Aliad,
    Sounds like an exciting CAVE-like project. This question may be more appropriate for the Steam forums, but I can put on my LBE hat and take a stab at answering it based on what I know. As far as signals in a room, BLE has a channel limit of 37, so your hope of 30 controllers is theoretically possible... however, keep in mind that the base stations also use Bluetooth so that will take up 4 channels. The best advice I can give is that you run a practical test in a noisy environment, either the actual venue or install location or somewhere similar in terms of surrounding technology. I'm not sure where this installation would be, but based on my experience building/running Vive arenas for location-based entertainment, 16 was just about the practical limit for a dedicated room/arena space. In some noisier arcades/venues we had to reduce to 8 or 10 for reliability, so just keep that in mind as far as environmental testing. Do it early so your game design and system design won't need to be changed at the end of development.

    In terms of Unity support, your limitation won't be based on the game engine but rather how many Vive Controllers are supported simultaneously by a single SteamVR runtime. With the default configuration it only supports 2 controllers tracking at the same time. You can pair more, but SteamVR will only pick up 2 at a time. So you will need to run separate PCs, each with 2 controllers tracking and just make sure to sync your universe files (lighthouse.db and chaperone) across them so the tracking space is consistent. Depending on how you are delivering video to your projectors, the PC-scale problem might be solved for you.
     
    VRDave_Unity, Jan 24, 2023
    #2
    Anthony_Aliad likes this.

  3. Anthony_Aliad

    Anthony_Aliad

    Joined:
    Jan 24, 2023
    Posts:
    2
    Thanks a lot @VRDave_Unity for your time and this detailed answer.

    The purpose of this project is to make this installation mobile from schools to schools - therefore it will be hard to ensure a validation in a "worst case" environment in terms of EM noise - and therefore the potential impact on reliability remains a strong concern.

    Regarding the SteamVR runtime limitation, the multiPC solution is indeed a good option (then I "only" need to check what would be the minimal setup for it and/or what would be the best trade-off by dispatching the projection across these PCs)

    I came across the libsurvive git development which seems to overcome this 2 controllers limitation, but it may be a bit 'hacky' for this project that needs to be very reliable and easy to maintain.

    I'm also checking hands detection through ToF cameras I'm really unsure of how good they could deliver with a group of kids so I'd rather stick to 6dof VR controllers.
     
    Anthony_Aliad, Jan 25, 2023
    #3