2025-07-27 :

the unspoken openxr vendor extension

XR_MNDX_xdev_space

have you ever heard of this
probably not, because there is less than a page of google search results when you search it up.
from what i understand, its an openxr extension for generic trackers in xr like vive trackers.
this is the only proof i've seen of its existence outside of people asserting that it exists
today i join the internet canon of websites mentioning XR_MNDX_xdev_space
not even khronos group's website mentions this even though they are literally the creators of the openxr specification

yeah uh i encountered this trying to figure out how to get fbt working in a bevy xr app i was making. i wanted to make a vr ddr pad as an open xr overlay to use while in vrchat. turns out bevy xr doesn't support fbt and you have to write in support yourself, and monado / wivrn on linux supposedly only use the XR_MNDX_xdev_space extension instead of using XR_HTCX_vive_tracker_interaction because why not i guess. why use the standard vendor extension for vive trackers when you can make a new one

this is what i get for trying to develop xr apps on linux. well also i haven't seen any way to make a open xr overlay in unity anyways so i'd still either need to use raw open xr or bevy xr. contact me on discord at dicedmangoes if you know how to do it in unity or godot

update: 7-28-2025

I have indirectly caused this to get implemented in a fork of bevy xr
here
well time to make my vr ddr pad!!!
i'm excited because the implementation works really well
all i need to do now is measure foot velocity for the pad to work