{
  "date": "2026-09-16",
  "provider": "City of Helsinki, City Survey Services; YLRE; Urban Environment Division",
  "license": "CC BY 4.0",
  "licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
  "cityModel": "https://kartta.hel.fi/3d/",
  "sourceWFS": "https://kartta.hel.fi/ws/geoserver/avoindata/wfs",
  "lod2Source": "https://kartta.hel.fi/3d/datasource-data/16fc3fd5-df6d-4f48-bfd5-9aeee430a02f/",
  "texturedLod2Source": "https://kartta.hel.fi/3d/datasource-data/e5e7158a-52df-45a1-9be0-1be8f2828abd/",
  "mobilityLayers": ["avoindata:Liikennevaylat", "avoindata:Liikennevalot_piste"],
  "architecturalOverrides": {
    "cathedralRatu": 211,
    "architectureReference": "https://helsingintuomiokirkko.fi/en/index/historyofthecathedral.html",
    "photoReference": "https://finland.fi/life-society/view-the-heart-of-helsinki-cathedral/",
    "method": "Measured alignment/lower roof geometry plus reconstructed colonnades, smooth domes, window surrounds, terrace and steps. No photograph is mapped onto the bespoke cathedral.",
    "unverifiedParameters": {"terraceRiseMetres": 8.4, "stairTreads": 46, "stairMeshWidthMetres": 64},
    "limitations": "Architectural proportions, sculptural silhouettes and stair rise are approximate. Raised structures block navigation; steps are not climbable. Other corridor landmarks do not yet have bespoke models."
  },
  "tramData": {"attribution": "© HSL 2026", "date": "2026-09-16", "license": "CC BY 4.0", "source": "https://www.hsl.fi/en/hsl/open-data", "details": "/models/tram-sources.json", "limitations": "Dated route shapes, not surveyed track centres or live traffic; simplified stops, switches and priorities"},
  "additionalArchitecture": {"pavilions": "RATU 212/213: Blender-authored GLB; measured envelopes and photo-guided approximate details", "governmentPalace": "RATU 5: Senate-facing facade only, photo-guided geometric reconstruction", "references": "/models/senate-sources.json"},
  "landcover": {"source": "2025 municipal orthophotos", "license": "CC BY 4.0", "method": "Conservative 3 m vegetation classification, mapped-surface exclusions, union and smoothing", "limitations": "Inferred planting patches, not surveyed landscape boundaries"},
  "counts": {
    "footprints": 5168,
    "lod2Buildings": 5278,
    "texturedBuildings": 5207,
    "directedRoadEdges": 8714,
    "directedWalkingEdges": 31936,
    "signalisedJunctions": 184,
    "roads": 5707,
    "pavements": 13116,
    "parks": 14020,
    "trees": 15941,
    "fallbackFootprints": 21,
    "footprintsInsidePlayableRadius": 3716
  },
  "limitations": [
    "Terrain is flattened; building bases are levelled individually. Roof shapes retain measured relative geometry.",
    "LOD2 model and current footprint register may differ in survey date and coverage. Footprints without a matched model use a clearly documented estimated extrusion.",
    "Ordinary buildings retain municipal photographic textures plus inferred physical window/sill/roof-edge details. Detection is not a measured facade inventory. Cathedral uses a separate approximate architectural reconstruction. Road materials, paving joints, kerbs and lane markings are procedural approximations.",
    "Mapped trees use real positions but schematic canopy sizes. Moving traffic and pedestrians use measured routes with fictional volumes, speeds and basic local avoidance. Junction positions are measured; signal pole offsets and timings are inferred.",
    "No building-by-building on-site validation has been performed.",
    "The previous 2025 aerial imagery is retained only as reference assets; gameplay renders 3D meshes rather than an aerial-photo floor."
  ],
  "aerial": {
    "year": 2025,
    "sourceLayer": "avoindata:Ortoilmakuva_2025_5cm",
    "source": "https://kartta.hel.fi/ws/geoserver/avoindata/wms",
    "gameResolutionMetres": 0.29296875,
    "license": "CC BY 4.0",
    "tiles": 64
  }
}