I recently got hands-on with ArenaXR, an open-source platform out of CMU's Mixed Reality Labs, and tried their Find the Pinata Challenge. The idea is simple: a virtual piñata is placed somewhere in your physical space, and you have to move around and find it. What's actually happening underneath is more interesting than it sounds. The system has to track your position in real time and keep the piñata anchored to a fixed point in the real world, so it doesn't drift as you move around it. That's what makes it feel like it's actually sitting there in the room.

The same tracking and anchoring problem behind a game like this shows up anywhere you want digital objects to stay put in physical space: remote collaboration, walking someone through a 3D model for teaching, showing a client through a building before it exists, or training a robot in a shared environment. Getting the anchoring right is most of what makes any of that usable.

The video is set to an upbeat piano instrumental soundtrack by Nathaniel Nyakotey, and it's a quick look at where WebXR development stands right now. If you build with WebXR, study human-computer interaction, or just find mixed reality interesting, it's worth a few minutes.