HIDDEN SPECTRE 👻

An augmented-reality ghost-hunting web app — an homage to the LEGO® Hidden Side™ app, focused purely on the AR mechanics: ghosts roam your real-world space and you trap them with an aiming reticle.

Not affiliated with or endorsed by the LEGO Group. A fan-made tribute to the AR play concept.

What it does

World-tracked AR via WebXR (immersive-ar) on supported devices (Android Chrome, etc.).
Graceful fallback to a live camera feed + device-gyro look-around on devices without WebXR AR (e.g. most iOS Safari) — so it still works as a "point and turn" experience.
Roaming ghosts rendered as procedural glowing wisps in Three.js that drift, bob, and eventually flee.
Trap tool: aim the reticle at a ghost and hold the trap button to charge a capture. Fill the meter before it escapes.
HUD with live score, nearby count, off-screen direction hints, capture flash + haptics.

How to play

Open on a phone over HTTPS (camera/WebXR require a secure context).
Tap Begin the Hunt and grant camera + motion permissions.
Pan slowly to map the area, then turn your body to find ghosts.
Center a ghost in the reticle, hold the trap button until the green ring fills.

Tech

Three.js (ES module via CDN import map)
WebXR Device API with camera + DeviceOrientation fallback
Vanilla JS, no build step — static files only

Files

index.html        markup + screens
css/style.css     neon supernatural styling
js/ar-engine.js   WebXR / camera+gyro abstraction
js/ghost.js       procedural ghost mesh + behaviour
js/main.js        game loop, aiming, trapping, scoring

Running locally

Any static server over HTTPS works. For quick local testing:

npx serve .
# then open the https URL on your phone (use a tunnel like ngrok/cloudflared for device testing)

Notes & limitations

iOS Safari does not support immersive-ar; it uses the camera+gyro fallback (look-around only, ghosts are world-locked relative to your starting orientation).
Motion permission on iOS must be triggered by a user gesture — handled on the Begin button tap.
Lighting and a steady camera improve the illusion, same as the original.