ifc2brick.py

from rdflib import Namespace
from brickschema.namespaces import BRICK, RDF
from brickschema import Graph

NS = Namespace("ex:")

def ifc2brick(osobj):
    """
    Convert an IFC object from OpenShell to a Brick object.
    Returns the corresponding Brick graph for that object
    """
    g = Graph()
    g.bind("ns", NS)
    attrs = osobj.get_info()
    print(osobj, attrs)
    entity = NS[attrs["GlobalId"]]
    for brickClass, ifcDefn in brick2ifc.items():
        if osobj.is_a(ifcDefn["entity"]):
            continue
        for attr, value in ifcDefn.get("attributes", {}).items():
            if isinstance(value, list):
                if attrs.get("PredefinedType") not in value:
                    continue
            elif attrs.get("PredefinedValue", None) != value:
                continue
        g.add((entity, RDF.type, brickClass))
    return g


brick2ifc = {
    BRICK.Camera: {
        "entity": "IfcAudioVisualAppliance",
        "attributes": {
            "IfcAudioVisualApplianceType": "CAMERA",
        },
    },
    BRICK.AHU: {
        "entity": "IfcUnitaryEquipment",
        "attributes": {
            "IfcUnitaryEquipmentType": "AIRHANDLER",
        },
    },
    BRICK.Boiler: {
        "entity": "IfcBoiler",
    },
    BRICK.CRAC: {
        "entity": "IfcUnitaryEquipment",
        "attributes": {
            "IfcUnitaryEquipmentType": "AIRCONDITIONINGUNIT",
        },
    },
    BRICK.Chiller: {
        "entity": "IfcChiller",
    },
    BRICK.Compressor: {
        "entity": "IfcCompressor",
    },
    BRICK.Condenser: {
        "entity": "IfcCondenser",
    },
    BRICK.Cooling_Tower: {
        "entity": "IfcCoolingTower",
    },
    BRICK.Damper: {
        "entity": "IfcDamper",
    },
    BRICK.Fan: {
        "entity": "IfcFan",
    },
    BRICK.Filter: {
        "entity": "IfcFilter",
        "attributes": {
            # TODO: is this correct?
            "IfcFilterType": "AIRPARTICLEFILTER",
        },
    },
    BRICK.Heat_Exchanger: {
        "entity": "IfcHeatExchanger",
    },
    BRICK.Humidifier: {
        "entity": "IfcHumidifier",
    },
    BRICK.Pump: {
        "entity": "IfcPump",
    },
    BRICK.TerminalUnit: {
        "entity": "IfcAirTerminalBox",
    },
    BRICK.CAV: {
        "entity": "IfcAirTerminalBox",
        "attributes": {
            "IfcAirTerminalBoxType": "CONSTANTFLOW",
        },
    },
    BRICK.VAV: {
        "entity": "IfcAirTerminalBox",
        "attributes": {
            "IfcAirTerminalBoxType": ["VARIABLEFLOWPRESSUREDEPENDANT" ",VARIABLEFLOWPRESSUREINDEPENDANT"],
        },
    },
    BRICK.Valve: {
        "entity": "IfcValve",
        # TODO: how to get the "substance" flowing through valve? connect to IFC system?
    },
    BRICK.Thermostat: {
        "entity": "IfcUnitaryControlElement",
        "attributes": {
            "IfcUnitaryControlElementType": "THERMOSTAT",
        },
    },
    BRICK.Weather_Station: {
        "entity": "IfcUnitaryControlElement",
        "attributes": {
            "IfcUnitaryControlElementType": "WEATHERSTATION",
        },
    },

    # lighting
    BRICK.Luminaire: {
        "entity": "IfcLightFixture",
    },
    BRICK.Meter: {
        "entity": "IfcFlowMeter",
    },
    BRICK.Electric_Meter: {
        "entity": "IfcFlowMeter",
        "attributes": {
            "IfcFlowMeterType": "ENERGYMETER",
        },
    },
    BRICK.Gas_Meter: {
        "entity": "IfcFlowMeter",
        "attributes": {
            "IfcFlowMeterType": "GASMETER",
        },
    },
    BRICK.Water_Meter: {
        "entity": "IfcFlowMeter",
        "attributes": {
            "IfcFlowMeterType": "WATERMETER",
        },
    },
    BRICK.Motor: {
        "entity": "IfcElectricMotor",
    },
    BRICK.PV_Panel: {
        "entity": "IfcSolarDevice",
        "attributes": {
            "IfcSolarDeviceType": "SOLARPANEL",
        },
    },

    # Locations
    BRICK.Building: {
        "entity": "IfcBuilding",
    },
    BRICK.Floor: {
        "entity": "IfcBuildingStorey",
    },
    BRICK.Space: {
        "entity": "IfcSpace",
    },
    BRICK.Zone: {
        "entity": "IfcSpatialZone",
    },
    BRICK.HVAC_Zone: {
        "entity": "IfcSpatialZone",
        "attributes": {
            "IfcSpatialZoneType": "THERMAL",
        },
    },
    BRICK.Lighting_Zone: {
        "entity": "IfcSpatialZone",
        "attributes": {
            "IfcSpatialZoneType": "LIGHTING",
        },
    },
}

if __name__ == "__main__":
    import ifcopenshell

    ifc_file = ifcopenshell.open('path/to/ifc/file.ifc')
    
    # if you want to use this w/ blenderbim
#     import blenderbim.tool as tool
#     ifc_file = tool.Ifc.get()

    #o = ifc_file.create_entity("IfcSpace")
    #print(o)

    g = Graph()
    for element in ifc_file.by_type("IfcElement") + ifc_file.by_type("IfcSpatialStructureElement"):
        b = ifc2brick(element)
        if len(b):
            g += b

    g.serialize('test.ttl', format="turtle")