VR Reality (VRR) Compiler — Digital Twins

Compiles HoloScript to 1:1 geo-synced digital twin environments delivered as browser-native WebXR. The VRR compiler bridges spatial computing and the real world: a .holo file becomes a live, interactive mirror of a real physical location.

Overview

The VRR compiler (--target vrr) is HoloScript's most ambitious output target — it generates WebXR scenes that are:

Geo-synced — positioned to real-world GPS coordinates
1:1 scale — centimeter-accurate to the physical environment
Live-data-fed — weather, traffic, IoT sensors, crowd density
Browser-native — no app store, no install, WebXR in Chrome/Edge

The reference implementation is Phoenix downtown: a navigable 1:1 digital twin of the Phoenix, AZ city core runnable in a VR headset browser.

bash

holoscript compile city.holo --target vrr --output ./twin/

Output Structure

twin/
  index.html           # WebXR entry point
  scene.gltf           # Geo-referenced 3D scene
  layers/
    buildings.glb      # OSM-sourced geometry
    terrain.glb        # Elevation mesh
    roads.glb          # Navigable road network
    iot-overlay.json   # Live sensor positions
  tiles/               # Streaming tile cache
  data/
    weather.json       # Live weather feed config
    traffic.json       # Traffic API config

Composition Structure

holo

composition "PhoenixDowntown" {
  environment {
    geo_anchor: { lat: 33.4484, lon: -112.0740, alt: 331 }
    scale: "1:1"
    data_feeds: ["openweathermap", "here-traffic", "iot-mesh"]
  }

  spatial_group "CityCore" {
    terrain {
      source: "usgs-elevation"
      resolution: "1m"
    }

    buildings {
      source: "osm"
      lod: [50, 200, 1000]  // LOD switch distances in meters
    }

    roads {
      source: "openstreetmap"
      @navigable
    }
  }

  layer "IoTOverlay" {
    @iot_sensor
    @digital_twin
    source: "hololand-mesh"
    refresh_rate: 5hz
  }

  logic {
    on_user_enter {
      load_live_data()
      start_feeds()
    }
  }
}

Live Data Integration

Data Source	Default Feed	Trait
Weather (temp, wind)	OpenWeatherMap API	`@iot_sensor`
Traffic density	HERE / TomTom	`@digital_twin`
Air quality (AQI)	OpenAQ	`@telemetry`
Build occupancy	IoT sensor mesh	`@mqtt_bridge`
Pedestrian flow	Computer vision feeds	`@telemetry`
Transit (buses, rail)	GTFS real-time	`@digital_twin`

Compiler Options

Option	Default	Description
`--vrr-geo`	required	`lat,lon,alt` of scene origin
`--vrr-radius`	500	Radius in metres to load
`--vrr-sources`	osm,usgs	Geometry sources (comma-separated)
`--vrr-lod`	50,200,500	LOD switch distances (metres)
`--vrr-feeds`	none	Live data feed IDs (comma-separated)
`--vrr-tile-size`	256	Streaming tile size (metres)
`--vrr-webxr-mode`	immersive-vr	`immersive-vr`, `immersive-ar`, `inline`

Use Cases

Urban planning — architects walk city plans at 1:1 scale
Emergency simulation — first-responder training in real building layouts
Retail analytics — foot-traffic heatmaps overlaid on real stores
Infrastructure monitoring — IoT sensors visible in spatial context
Tourism — remote visitors explore real places in VR
Hololand platform — the foundational layer for all Hololand experiences

VR Reality (VRR) Compiler — Digital Twins ​

Overview ​

Output Structure ​

Composition Structure ​

Live Data Integration ​

Compiler Options ​

Use Cases ​

See Also ​