{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "CityJSON v0.6",
  "description": "CityJSON specifications v0.6",
  "type": "object",


  "properties": {
    "type": { "enum": ["CityJSON"] },
    "version": { 
      "type": "string",
      "pattern": "\\d.\\d"
    },
    "metadata": {
      "type": "object",
      "properties": {
        "crs": {
          "type": "object",
          "properties": {
            "epsg": {"type": "integer"}
          },
          "required": ["epsg"]
        },
        "bbox": {
          "type": "array",
          "items": {
            "type": "number"
          },
          "minItems": 6,    
          "maxItems": 6    
        },
        "keywords": {
          "type": "array",
          "items": {"type": "string"}
        },        
        "datasetTitle": {"type": "string"},
        "datasetReferenceDate": {"type": "string"},
        "geographicLocation": {
          "type": "string",
          "description": "the name of the area for instance"
        },
        "datasetLanguage": {"type": "string"},
        "datasetTopicCategory": {
          "type": "string",
          "description": "see Table B.3.30 in ISO19115 document"
        },
        "datasetAbstract": {"type": "string"},
        "metadataDateStamp": {"type": "string"},
        "pointOfContact": {"type": "string"},
        "copyright": {"type": "string"},
        "presentLoDs":  {
          "type": "array",
          "items": {"type": "number"}
        }
      }
    },
    "CityObjects": {
      "type": "object",
      "additionalProperties": {
        "oneOf": [
          { "$ref": "cityobjects.json#/Building" },
          { "$ref": "cityobjects.json#/BuildingPart" },
          { "$ref": "cityobjects.json#/BuildingInstallation" },
          { "$ref": "cityobjects.json#/Road" },
          { "$ref": "cityobjects.json#/Railway" },
          { "$ref": "cityobjects.json#/TransportSquare" },
          { "$ref": "cityobjects.json#/TINRelief" },
          { "$ref": "cityobjects.json#/WaterBody" },
          { "$ref": "cityobjects.json#/LandUse" },
          { "$ref": "cityobjects.json#/GenericCityObject" },
          { "$ref": "cityobjects.json#/CityFurniture" },
          { "$ref": "cityobjects.json#/SolitaryVegetationObject" },
          { "$ref": "cityobjects.json#/PlantCover" },
          { "$ref": "cityobjects.json#/Bridge" },
          { "$ref": "cityobjects.json#/BridgePart" },
          { "$ref": "cityobjects.json#/BridgeInstallation" },
          { "$ref": "cityobjects.json#/BridgeConstructionElement" },
          { "$ref": "cityobjects.json#/Tunnel" },
          { "$ref": "cityobjects.json#/TunnelPart" },
          { "$ref": "cityobjects.json#/TunnelInstallation" }
        ]
      }
    },
    "vertices": {
      "type": "array",
      "items": {
        "type": "array",
        "items": {"type": "number"},
        "minItems": 3,    
        "maxItems": 3
      }
    },
    "transform": {
      "type": "object",
      "properties": {
        "scale": {
          "type": "array",
          "items": {"type": "number"},
          "minItems": 3,    
          "maxItems": 3
        },
        "translate": {
          "type": "array",
          "items": {"type": "number"},
          "minItems": 3,    
          "maxItems": 3
        }
      },
      "required": ["scale", "translate"],
      "additionalProperties": false
    },
    "appearance": {
      "type": "object",
      "properties": {
        "default-theme-texture": {"type": "string"},
        "default-theme-material": {"type": "string"},
        "materials": {
          "type": "array",
          "items": {"$ref": "appearance.json#/Material"}
        },
        "textures": {
          "type": "array",
          "items": {"$ref": "appearance.json#/Texture"}
        },
        "vertices-texture": {
          "type": "array",
          "items": {
            "type": "array",
            "items": {"type": "number"},
            "minItems": 2,    
            "maxItems": 2
          }
        }
      },
      "additionalProperties": false
    }
  },
  "required": ["type", "version", "CityObjects", "vertices"],
  "additionalProperties": false
}