// The IfcHierarchyHelper is a subclass of the regular IfcFile that provides several

// convenience functions for working with geometry in IFC files.

IfcHierarchyHelper<IfcSchema> file;

file.header().file_name()->setname("IfcAdvancedHouse.ifc");

IfcSchema::IfcBuilding* building = file.addBuilding();

// By adding a building, a hierarchy has been automatically created that consists of the following

// structure: IfcProject > IfcSite > IfcBuilding

// Lateron changing the name of the IfcProject can be done by obtaining a reference to the

// project, which has been created automatically.

file.getSingle<IfcSchema::IfcProject>()->setName("IfcAdvancedHouse"s);

// To demonstrate the ability to serialize arbitrary opencascade solids a building envelope is

// constructed by applying boolean operations. Naturally, in IFC, building elements should be

// modeled separately, with rich parametric and relational semantics. Creating geometry in this

// way does not preserve any history and is merely a demonstration of technical capabilities.

TopoDS_Shape outer = BRepPrimAPI_MakeBox(gp_Pnt(-5000., -180., -2000.), gp_Pnt(5000., 5180., 3000.)).Shape();

TopoDS_Shape inner = BRepPrimAPI_MakeBox(gp_Pnt(-4640., 180., 0.), gp_Pnt(4640., 4820., 3000.)).Shape();

TopoDS_Shape window1 = BRepPrimAPI_MakeBox(gp_Pnt(-5000., -180., 400.), gp_Pnt( 500., 1180., 2000.)).Shape();

TopoDS_Shape window2 = BRepPrimAPI_MakeBox(gp_Pnt( 2070., -180., 400.), gp_Pnt(3930., 180., 2000.)).Shape();

TopoDS_Shape building_shell = BRepAlgoAPI_Cut(

BRepAlgoAPI_Cut(

BRepAlgoAPI_Cut(outer, inner),

window1

),

window2

);

// Since the solid consists only of planar faces and straight edges it can be serialized as an

// IfcFacetedBRep. If it would not be a polyhedron, serialise() can only be successful when linked

// to the IFC4 model and with `advanced` set to `true` which introduces IfcAdvancedFace. It would

// return `0` otherwise.

IfcSchema::IfcProductDefinitionShape* building_shape = IfcGeom::serialise(STRINGIFY(IfcSchema), building_shell, false)->as<IfcSchema::IfcProductDefinitionShape>();

file.addEntity(building_shape);

IfcSchema::IfcRepresentation* rep = *building_shape->Representations()->begin();

rep->setContextOfItems(file.getRepresentationContext("model"));

building->setRepresentation(building_shape);

// A pale white colour is assigned to the building.

setSurfaceColour(file, building_shape, 0.75, 0.73, 0.68);

// For the ground mesh of the IfcSite we will use a Nurbs surface created in Open Cascade. Only

// in IFC4 the surface can be directly serialized. In IFC2X3 the it will have to be tessellated.

TopoDS_Shape shape;

createGroundShape(shape);

auto ground_representation = IfcGeom::serialise(STRINGIFY(IfcSchema), shape, true);

if (!ground_representation) {

ground_representation = IfcGeom::tesselate(STRINGIFY(IfcSchema), shape, 100.);

}

file.getSingle<IfcSchema::IfcSite>()->setRepresentation(ground_representation->as<IfcSchema::IfcProductDefinitionShape>());

IfcSchema::IfcRepresentation::list::ptr ground_reps = file.getSingle<IfcSchema::IfcSite>()->Representation()->Representations();

for (IfcSchema::IfcRepresentation::list::it it = ground_reps->begin(); it != ground_reps->end(); ++it) {

(*it)->setContextOfItems(file.getRepresentationContext("Model"));

}

file.addEntity(ground_representation);

setSurfaceColour(file, ground_representation->as<IfcSchema::IfcProductDefinitionShape>(), 0.15, 0.25, 0.05);

/*

// Finally create a file stream for our output and write the IFC file to it.

std::ofstream f("IfcAdvancedHouse.ifc");

f << file;

TColgp_Array2OfPnt cv (0, 4, 0, 4);

cv.SetValue(0, 0, gp_Pnt(-10000, -10000, -4130));

cv.SetValue(0, 1, gp_Pnt(-10000, -4330, -4130));

cv.SetValue(0, 2, gp_Pnt(-10000, 0, -5130));

cv.SetValue(0, 3, gp_Pnt(-10000, 4330, -7130));

cv.SetValue(0, 4, gp_Pnt(-10000, 10000, -7130));

cv.SetValue(1, 0, gp_Pnt( -3330, -10000, -5130));

cv.SetValue(1, 1, gp_Pnt( -7670, -3670, 5000));

cv.SetValue(1, 2, gp_Pnt( -9000, 0, 1000));

cv.SetValue(1, 3, gp_Pnt( -7670, 7670, 6000));

cv.SetValue(1, 4, gp_Pnt( -3330, 10000, -4130));

cv.SetValue(2, 0, gp_Pnt( 0, -10000, -5530));

cv.SetValue(2, 1, gp_Pnt( 0, -3670, 3000));

cv.SetValue(2, 2, gp_Pnt( 0, 0, -12000));

cv.SetValue(2, 3, gp_Pnt( 0, 7670, 1500));

cv.SetValue(2, 4, gp_Pnt( 0, 10000, -4130));

cv.SetValue(3, 0, gp_Pnt( 3330, -10000, -6130));

cv.SetValue(3, 1, gp_Pnt( 7670, -3670, 6000));

cv.SetValue(3, 2, gp_Pnt( 9000, 0, 5000));

cv.SetValue(3, 3, gp_Pnt( 7670, 9000, 7000));

cv.SetValue(3, 4, gp_Pnt( 3330, 10000, -4130));

cv.SetValue(4, 0, gp_Pnt( 10000, -10000, -6130));

cv.SetValue(4, 1, gp_Pnt( 10000, -4330, -5130));

cv.SetValue(4, 2, gp_Pnt( 10000, 0, -4130));

cv.SetValue(4, 3, gp_Pnt( 10000, 4330, -4130));

cv.SetValue(4, 4, gp_Pnt( 10000, 10000, -8130));

TColStd_Array1OfReal knots(0, 1);

knots(0) = 0;

knots(1) = 1;

TColStd_Array1OfInteger mult(0, 1);

mult(0) = 5;

mult(1) = 5;

Handle(Geom_BSplineSurface) surf = new Geom_BSplineSurface(cv, knots, knots, mult, mult, 4, 4);

#if OCC_VERSION_HEX < 0x60502

shape = BRepBuilderAPI_MakeFace(surf);

#else

shape = BRepBuilderAPI_MakeFace(surf, Precision::Confusion());

#endif