Vision Pet

The problem

Most virtual pets live inside a screen. On Vision Pro a pet can share your actual space, but only if he understands it: where the floor is, where the couch is, where your hands are. And if he's going to feel alive, his needs have to fit a real person's day instead of nagging them every hour.

What I built

• A pet brain built on RealityKit's entity component system, with 47 custom components and systems for movement, needs, mood and behavior.
• ARKit world, plane and hand tracking so he can find your floor and furniture and respond to your hands.
• Navigation-mesh roaming so he walks around obstacles instead of through them.
• Hand-tracked petting: stroke his back or scratch behind his ears and he reacts.
• SharePlay, so a friend can see him too.
• iPhone and Apple Watch companions that share one simulation core with the Vision Pro app, so his care stays in step across devices.

Hard parts

Tuning care to a few minutes a day

A pet that needs too much attention becomes a chore, and one that needs too little feels fake. Instead of guessing, I wrote a headless balance simulator where bots with different habits play the real game engine for months of game time in seconds. I used the reports to tune his care to about 10 minutes of play a day.

Bugs that only show up on real hardware

I run structured audits on a real Vision Pro and Apple Watch, not just the simulator. One of those audits caught a 32-bit integer overflow that only happened on actual Watch hardware and never in testing on a Mac.

Testing something that moves

Behavior that depends on time, mood and the room is easy to break without noticing. The app has about 2,200 Swift Testing cases covering the simulation, so changes to one behavior don't quietly break another.

Where it stands

Vision Pet is in development, with on-device testing on Vision Pro and Apple Watch. See the app's page at Bang Bang Studios.