location-ar-experience

Use ARCore's Geospatial API or ARKit's ARGeoAnchor to create anchors at latitude, longitude, and altitude coordinates. Check that tracking state is TRACKING and horizontal accuracy is under 10 meters before creating anchors.

GPS-only positioning achieves roughly 5-15 meters accuracy, suitable for city navigation. Hybrid GPS plus vision reaches 1-2 meters, while pure visual SLAM achieves 1-10 centimeter precision for object placement.

ARKit offers ARGeoAnchor with geo tracking on iOS 14+, while ARCore provides the Geospatial API with terrain and rooftop anchors on Android. Both support VPS-based visual positioning, but availability varies by location and device.

Implement geofences with enter, exit, and dwell callbacks that check if the user's position falls within a defined radius. Use tiered interaction zones: awareness at 100m, preview at 50m, activation at 20m, and interaction at 5m.

Anchors fail when VPS is unavailable at the location, tracking state is not TRACKING, or horizontal accuracy exceeds thresholds. Check VPS availability first, move to an open area, and verify location permissions are granted.

Adjust GPS configuration based on context: use high accuracy with 1-second intervals near content, but balanced accuracy with 5-second intervals otherwise. Disable geospatial mode when the app is backgrounded and only update the AR scene after 5 meters of movement.