Wrote a WebXR drawing tool with passthrough (i.e. AR overlay), in order to draw lines over real-world surfaces. It's pretty handy!
Uploaded it as Freebird Lite. It proved itself useful yesterday, since I could sketch lines around the house to plan different fittings and show the ideas to others (using the headset). Since it's just a website in a browser, it doesn't require any installation. And it works on all the compatible 6 DoF headsets.
For now, it will only let you draw lines in the air. That was all I needed yesterday.
The main limitation right now is that it doesn't "anchor" things correctly, i.e. it resets the orientation when the headset recenters (e.g. after Quest wakes up from sleep). So the lines will no longer be where you drew them (relative to the real-world surfaces). I'm already using anchored elements, but clearly I'm doing it wrong.
Dev note - I created a self-signed certificate for my PC, so I can access it (over LAN) from the Quest. Debugging over temporary Cloudflare tunnels was pretty inconvenient.