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IfcOpenShell/src/examples/IfcAlignment.cpp
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Thomas Krijnen d8799d799e Fixes for 4.3 compilation
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/********************************************************************************
* *
* This file is part of IfcOpenShell. *
* *
* IfcOpenShell is free software: you can redistribute it and/or modify *
* it under the terms of the Lesser GNU General Public License as published by *
* the Free Software Foundation, either version 3.0 of the License, or *
* (at your option) any later version. *
* *
* IfcOpenShell is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* Lesser GNU General Public License for more details. *
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* You should have received a copy of the Lesser GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
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********************************************************************************/
// This example illustrates the basic of building an alignment model.
// The alignment is based on "Bridge Geometry Manual", April 2022
// US Department of Transportation, Federal Highway Administration (FHWA)
// https://www.fhwa.dot.gov/bridge/pubs/hif22034.pdf
//
// Sections and page number for this document are cited in the code comments.
//
// This examples differs from IfcSimplifiedAlignment because it builds the
// alignment explicitly
// Disable warnings coming from IfcOpenShell
#pragma warning(disable : 4018 4267 4250 4984 4985)
#include "../ifcparse/schemas/Ifc4x3_add2.h"
#include "../ifcparse/hierarchy_helper.h"
#include <boost/math/constants/constants.hpp>
#include <fstream>
const double PI = boost::math::constants::pi<double>();
double to_radian(double deg) { return PI * deg / 180; }
#define Schema Ifc4x3_add2
// performs basic project setup including created the IfcProject object
// and initializing the project units to FEET
Schema::IfcProject setup_project(hierarchy_helper<Schema>& file) {
std::vector<std::string> file_description;
file_description.push_back("ViewDefinition[Alignment-basedReferenceView]");
file.header().file_description().setdescription(file_description);
auto project = file.addProject();
project.setName("FHWA Bridge Geometry Manual Example Alignment");
project.setDescription("C++ Example");
// set up project units for feet
// the call to file.addProject() sets up length units as millimeter.
auto units_in_context = project.UnitsInContext();
auto units = units_in_context.Units();
auto begin = units.begin();
auto iter = begin;
auto end = units.end();
for (; iter != end; iter++) {
auto& unit = *iter;
if (unit.as<Schema::IfcSIUnit>() && unit.as<Schema::IfcSIUnit>().UnitType() == Schema::IfcUnitEnum::IfcUnit_LENGTHUNIT) {
auto dimensions = file.create<Schema::IfcDimensionalExponents>();
dimensions.setLengthExponent(1);
dimensions.setMassExponent(0);
dimensions.setTimeExponent(0);
dimensions.setElectricCurrentExponent(0);
dimensions.setThermodynamicTemperatureExponent(0);
dimensions.setAmountOfSubstanceExponent(0);
dimensions.setLuminousIntensityExponent(0);
auto conversion_factor = file.create<Schema::IfcMeasureWithUnit>();
auto length = file.create<Schema::IfcLengthMeasure>();
length.set_attribute_value(0, 304.80);
conversion_factor.setValueComponent(length);
conversion_factor.setUnitComponent(unit);
auto conversion_based_unit = file.create<Schema::IfcConversionBasedUnit>();
conversion_based_unit.setDimensions(dimensions);
conversion_based_unit.setUnitType(Schema::IfcUnitEnum::IfcUnit_LENGTHUNIT);
conversion_based_unit.setName("FEET");
conversion_based_unit.setConversionFactor(conversion_factor);
units.erase(std::remove(units.begin(), units.end(), unit)); // remove the millimeter unit
units.push_back(conversion_based_unit); // add the feet unit
units_in_context.setUnits(units); // update the UnitsInContext
break; // Done!, the length unit was found, so break out of the loop
}
}
return project;
}
// creates geometry and business logic segments for horizontal alignment tangent runs
std::pair<typename Schema::IfcCurveSegment, typename Schema::IfcAlignmentSegment> create_tangent(hierarchy_helper<Schema>& file, const typename Schema::IfcCartesianPoint& p, double dir, double length) {
// geometry
auto parent_curve = file.create<Schema::IfcLine>();
parent_curve.setPnt(file.addDoublet<Schema::IfcCartesianPoint>(0.0, 0.0));
auto vec = file.create<Schema::IfcVector>();
vec.setOrientation(file.addDoublet<Schema::IfcDirection>(1.0, 0.0));
vec.setMagnitude(1.0);
parent_curve.setDir(vec);
auto place = file.create<Schema::IfcAxis2Placement2D>();
place.setLocation(p);
place.setRefDirection(file.addDoublet<Schema::IfcDirection>(cos(dir), sin(dir)));
auto curve_segment = file.create<Schema::IfcCurveSegment>();
curve_segment.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_CONTSAMEGRADIENT);
curve_segment.setPlacement(place);
curve_segment.setSegmentStart(file.addValue<Schema::IfcLengthMeasure>(0.0));
curve_segment.setSegmentLength(file.addValue<Schema::IfcLengthMeasure>(length));
curve_segment.setParentCurve(parent_curve);
// business logic
auto design_parameters = file.create<Schema::IfcAlignmentHorizontalSegment>();
design_parameters.setStartPoint(p);
design_parameters.setStartDirection(dir);
design_parameters.setStartRadiusOfCurvature(0.0);
design_parameters.setEndRadiusOfCurvature(0.0);
design_parameters.setSegmentLength(length);
design_parameters.setPredefinedType(Schema::IfcAlignmentHorizontalSegmentTypeEnum::IfcAlignmentHorizontalSegmentType_LINE);
auto alignment_segment = file.create<Schema::IfcAlignmentSegment>();
alignment_segment.setGlobalId(ifcopenshell::global_id());
alignment_segment.setDesignParameters(design_parameters);
return {curve_segment, alignment_segment};
}
// creates geometry and business logic segments for horizontal alignment horizonal curves
std::pair<typename Schema::IfcCurveSegment, typename Schema::IfcAlignmentSegment> create_hcurve(hierarchy_helper<Schema>& file, const typename Schema::IfcCartesianPoint& pc, double dir, double radius, double lc) {
// geometry
double sign = radius / fabs(radius);
auto place = file.create<Schema::IfcAxis2Placement2D>();
place.setLocation(file.addDoublet<Schema::IfcCartesianPoint>(0.0, 0.0));
place.setRefDirection(file.addDoublet<Schema::IfcDirection>(1.0, 0.0));
auto parent_curve = file.create<Schema::IfcCircle>();
parent_curve.setPosition(place);
parent_curve.setRadius(fabs(radius));
auto place2 = file.create<Schema::IfcAxis2Placement2D>();
place2.setLocation(pc);
place2.setRefDirection(file.addDoublet<Schema::IfcDirection>(cos(dir), sin(dir)));
auto curve_segment = file.create<Schema::IfcCurveSegment>();
curve_segment.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_CONTSAMEGRADIENT);
curve_segment.setPlacement(place2);
curve_segment.setSegmentStart(file.addValue<Schema::IfcLengthMeasure>(0.0));
curve_segment.setSegmentLength(file.addValue<Schema::IfcLengthMeasure>(sign * lc));
curve_segment.setParentCurve(parent_curve);
// business logic
auto design_parameters = file.create<Schema::IfcAlignmentHorizontalSegment>();
design_parameters.setStartPoint(pc);
design_parameters.setStartDirection(dir);
design_parameters.setStartRadiusOfCurvature(radius);
design_parameters.setEndRadiusOfCurvature(radius);
design_parameters.setSegmentLength(lc);
design_parameters.setPredefinedType(Schema::IfcAlignmentHorizontalSegmentTypeEnum::IfcAlignmentHorizontalSegmentType_CIRCULARARC);
auto alignment_segment = file.create<Schema::IfcAlignmentSegment>();
alignment_segment.setGlobalId(ifcopenshell::global_id());
alignment_segment.setDesignParameters(design_parameters);
return {curve_segment, alignment_segment};
}
// creates geometry and business logic segments for vertical profile gradient runs
std::pair<typename Schema::IfcCurveSegment, typename Schema::IfcAlignmentSegment> create_gradient(hierarchy_helper<Schema>& file, const typename Schema::IfcCartesianPoint& p, double slope, double length) {
// geometry
auto parent_curve = file.create<Schema::IfcLine>();
parent_curve.setPnt(file.addDoublet<Schema::IfcCartesianPoint>(0.0, 0.0));
auto vec = file.create<Schema::IfcVector>();
vec.setOrientation(file.addDoublet<Schema::IfcDirection>(1.0, 0.0));
vec.setMagnitude(1.0);
parent_curve.setDir(vec);
auto place2 = file.create<Schema::IfcAxis2Placement2D>();
place2.setLocation(p);
place2.setRefDirection(file.addDoublet<Schema::IfcDirection>(sqrt(1 - slope * slope), slope));
auto curve_segment = file.create<Schema::IfcCurveSegment>();
curve_segment.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_CONTSAMEGRADIENT);
curve_segment.setPlacement(place2);
curve_segment.setSegmentStart(file.addValue<Schema::IfcLengthMeasure>(0.0));
curve_segment.setSegmentLength(file.addValue<Schema::IfcLengthMeasure>(length));
curve_segment.setParentCurve(parent_curve);
// business logic
auto design_parameters = file.create<Schema::IfcAlignmentVerticalSegment>();
design_parameters.setStartDistAlong(p.Coordinates()[0]);
design_parameters.setHorizontalLength(length);
design_parameters.setStartHeight(p.Coordinates()[1]);
design_parameters.setStartGradient(slope);
design_parameters.setEndGradient(slope);
design_parameters.setPredefinedType(Schema::IfcAlignmentVerticalSegmentTypeEnum::IfcAlignmentVerticalSegmentType_CONSTANTGRADIENT);
auto alignment_segment = file.create<Schema::IfcAlignmentSegment>();
alignment_segment.setGlobalId(ifcopenshell::global_id());
alignment_segment.setDesignParameters(design_parameters);
return {curve_segment, alignment_segment};
}
// creates geometry and business logic segments for vertical profile parabolic vertical curves
std::pair<typename Schema::IfcCurveSegment, typename Schema::IfcAlignmentSegment> create_vcurve(hierarchy_helper<Schema>& file, const typename Schema::IfcCartesianPoint& p, double start_slope, double end_slope, double length) {
// geometry
double A = p.Coordinates()[1];
double B = start_slope;
double C = (end_slope - start_slope) / (2 * length);
auto place = file.create<Schema::IfcAxis2Placement2D>();
place.setLocation(file.addDoublet<Schema::IfcCartesianPoint>(0.0, 0.0));
place.setRefDirection(file.addDoublet<Schema::IfcDirection>(1.0, 0.0));
auto parent_curve = file.create<Schema::IfcPolynomialCurve>();
parent_curve.setPosition(place);
parent_curve.setCoefficientsX(std::vector<double>{0.0, 1.0});
parent_curve.setCoefficientsY(std::vector<double>{A, B, C});
auto place2 = file.create<Schema::IfcAxis2Placement2D>();
place2.setLocation(p);
place2.setRefDirection(file.addDoublet<Schema::IfcDirection>(sqrt(1 - start_slope * start_slope), start_slope));
auto curve_segment = file.create<Schema::IfcCurveSegment>();
curve_segment.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_CONTSAMEGRADIENT);
curve_segment.setPlacement(place2);
curve_segment.setSegmentStart(file.addValue<Schema::IfcLengthMeasure>(0.0));
curve_segment.setSegmentLength(file.addValue<Schema::IfcLengthMeasure>(length));
curve_segment.setParentCurve(parent_curve);
// business logic
double k = (end_slope - start_slope) / length;
auto design_parameters = file.create<Schema::IfcAlignmentVerticalSegment>();
design_parameters.setStartDistAlong(p.Coordinates()[0]);
design_parameters.setHorizontalLength(length);
design_parameters.setStartHeight(p.Coordinates()[1]);
design_parameters.setStartGradient(start_slope);
design_parameters.setEndGradient(end_slope);
design_parameters.setRadiusOfCurvature(1 / k);
design_parameters.setPredefinedType(Schema::IfcAlignmentVerticalSegmentTypeEnum::IfcAlignmentVerticalSegmentType_PARABOLICARC);
auto alignment_segment = file.create<Schema::IfcAlignmentSegment>();
alignment_segment.setGlobalId(ifcopenshell::global_id());
alignment_segment.setDesignParameters(design_parameters);
return {curve_segment, alignment_segment};
}
// creates representations for each IfcAlignmentSegment per CT 4.1.7.1.1.4
// https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/concepts/Product_Shape/Product_Geometric_Representation/Alignment_Geometry/Alignment_Geometry_-_Segments/content.html
void create_segment_representations(hierarchy_helper<Schema>& file, const Schema::IfcLocalPlacement& global_placement, const Schema::IfcGeometricRepresentationSubContext& segment_axis_subcontext, std::vector<Schema::IfcSegment>& curve_segments, std::vector<Schema::IfcObjectDefinition>& segments) {
auto cs_iter = curve_segments.begin();
auto s_iter = segments.begin();
for (; cs_iter != curve_segments.end(); cs_iter++, s_iter++) {
auto& curve_segment = *cs_iter;
auto alignment_segment = (*s_iter).as<Schema::IfcAlignmentSegment>();
auto axis_representation = file.create<Schema::IfcShapeRepresentation>();
axis_representation.setContextOfItems(segment_axis_subcontext);
axis_representation.setRepresentationIdentifier("Axis");
axis_representation.setRepresentationType("Segment");
axis_representation.setItems({curve_segment});
auto product = file.create<Schema::IfcProductDefinitionShape>();
product.setRepresentations({axis_representation});
alignment_segment.setObjectPlacement(global_placement);
alignment_segment.setRepresentation(product);
}
}
int main() {
hierarchy_helper<Schema> file;
auto project = setup_project(file);
auto geometric_representation_context = file.getRepresentationContext(std::string("Model")); // creates the representation context if it doesn't already exist
auto axis_model_representation_subcontext = file.create<Schema::IfcGeometricRepresentationSubContext>();
axis_model_representation_subcontext.setContextIdentifier("Axis");
axis_model_representation_subcontext.setContextType("Model");
axis_model_representation_subcontext.setParentContext(geometric_representation_context);
axis_model_representation_subcontext.setTargetView(Schema::IfcGeometricProjectionEnum::IfcGeometricProjection_MODEL_VIEW);
auto global_placement = file.addLocalPlacement();
//
// Define horizontal alignment
//
// define key points
// B.1.4 pg 212
auto pob = file.addDoublet<Schema::IfcCartesianPoint>(500, 2500); // beginning
auto pc1 = file.addDoublet<Schema::IfcCartesianPoint>(2142.237995, 1436.014820); // Point of curve (PC), Curve #1
auto pt1 = file.addDoublet<Schema::IfcCartesianPoint>(3660.446123, 2050.736173); // Point of tangent (PT), Curve #1
auto pc2 = file.addDoublet<Schema::IfcCartesianPoint>(4084.115884, 3889.462938); // Point of curve (PC), Curve #2
auto pt2 = file.addDoublet<Schema::IfcCartesianPoint>(5469.395067, 4847.566310); // Point of tangent (PT), Curve #2
auto pc3 = file.addDoublet<Schema::IfcCartesianPoint>(7019.971367, 4638.286073); // Point of curve (PC), Curve #3
auto pt3 = file.addDoublet<Schema::IfcCartesianPoint>(7790.932128, 4006.730765); // Point of tangent (PT), Curve #3
auto poe = file.addDoublet<Schema::IfcCartesianPoint>(8480, 2010); // ending
// define tangent runs and curve lengths
double run_1 = 1956.785654;
double lc_1 = 1919.222667;
double run_2 = 1886.905454;
double lc_2 = 1848.115835;
double run_3 = 1564.635765;
double lc_3 = 1049.119737;
double run_4 = 2112.285084;
// define curve radii
double rc_1 = 1000;
double rc_2 = -1250; // negative radius for curves to the right
double rc_3 = -950;
// bearing of tangents
double angle_1 = to_radian(327.0613);
double angle_2 = to_radian(77.0247);
double angle_3 = to_radian(352.3133);
double angle_4 = to_radian(289.0395);
// create containers to store the curve segments
std::vector<Schema::IfcSegment> horizontal_curve_segments; // geometry
std::vector<Schema::IfcObjectDefinition> horizontal_segments; // business logic
//
// Build the horizontal alignment segments
//
// POB to PC1
auto curve_segment_1 = create_tangent(file, pob, angle_1, run_1);
horizontal_curve_segments.push_back(curve_segment_1.first);
horizontal_segments.push_back(curve_segment_1.second);
// Curve 1
auto curve_segment_2 = create_hcurve(file, pc1, angle_1, rc_1, lc_1);
horizontal_curve_segments.push_back(curve_segment_2.first);
horizontal_segments.push_back(curve_segment_2.second);
// PT1 to PC2
auto curve_segment_3 = create_tangent(file, pt1, angle_2, run_2);
horizontal_curve_segments.push_back(curve_segment_3.first);
horizontal_segments.push_back(curve_segment_3.second);
// Curve 2
auto curve_segment_4 = create_hcurve(file, pc2, angle_2, rc_2, lc_2);
horizontal_curve_segments.push_back(curve_segment_4.first);
horizontal_segments.push_back(curve_segment_4.second);
// PT2 to PC3
auto curve_segment_5 = create_tangent(file, pt2, angle_3, run_3);
horizontal_curve_segments.push_back(curve_segment_5.first);
horizontal_segments.push_back(curve_segment_5.second);
// Curve 3
auto curve_segment_6 = create_hcurve(file, pc3, angle_3, rc_3, lc_3);
horizontal_curve_segments.push_back(curve_segment_6.first);
horizontal_segments.push_back(curve_segment_6.second);
// PT3 to POE
auto curve_segment_7 = create_tangent(file, pt3, angle_4, run_4);
horizontal_curve_segments.push_back(curve_segment_7.first);
horizontal_segments.push_back(curve_segment_7.second);
// Zero-length terminator segment
auto terminator_segment = create_tangent(file, poe, angle_4, 0.0);
terminator_segment.first.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_DISCONTINUOUS);
horizontal_curve_segments.push_back(terminator_segment.first);
horizontal_segments.push_back(terminator_segment.second);
//
// Create the horizontal alignment (IfcAlignmentHorizontal) and nest alignment segments
//
auto horizontal_alignment = file.create<Schema::IfcAlignmentHorizontal>();
horizontal_alignment.setGlobalId(ifcopenshell::global_id());
horizontal_alignment.setName("Example Alignment");
auto nests_horizontal_segments = file.create<Schema::IfcRelNests>();
nests_horizontal_segments.setGlobalId(ifcopenshell::global_id());
nests_horizontal_segments.setName("Nests horizontal alignment segments with horizontal alignment");
nests_horizontal_segments.setRelatingObject(horizontal_alignment);
nests_horizontal_segments.setRelatedObjects(horizontal_segments);
//
// Create plan view footprint model representation for the horizontal alignment
//
// start by defining a composite curve composed of the horizonal curve segments
auto composite_curve = file.create<Schema::IfcCompositeCurve>();
composite_curve.setSegments(horizontal_curve_segments);
composite_curve.setSelfIntersect(false);
// create the footprint representation
auto footprint_shape_representation = file.create<Schema::IfcShapeRepresentation>();
footprint_shape_representation.setContextOfItems(axis_model_representation_subcontext);
footprint_shape_representation.setRepresentationIdentifier("Footprint");
footprint_shape_representation.setRepresentationType("Curve2D");
// the composite curve is a representation item
footprint_shape_representation.setItems({composite_curve});
//
// Define vertical profile segments
//
// create containers to store the curve segments
std::vector<Schema::IfcSegment> vertical_curve_segments; // geometry
std::vector<Schema::IfcObjectDefinition> vertical_segments; // business logic
// define key profile points
auto vpob = file.addDoublet<Schema::IfcCartesianPoint>(0.0, 100.0); // beginning
auto vpc1 = file.addDoublet<Schema::IfcCartesianPoint>(1200.0, 121.0); // Vertical Curve Point (VPC), Vertical Curve #1
auto vpt1 = file.addDoublet<Schema::IfcCartesianPoint>(2800.0, 127.0); // Vertical Curve Tangent (VPT), Vertical Curve #1
auto vpc2 = file.addDoublet<Schema::IfcCartesianPoint>(4400.0, 111.0); // Vertical Curve Point (VPC), Vertical Curve #2
auto vpt2 = file.addDoublet<Schema::IfcCartesianPoint>(5600.0, 117.0); // Vertical Curve Tangent (VPT), Vertical Curve #2
auto vpc3 = file.addDoublet<Schema::IfcCartesianPoint>(6400.0, 133.0); // Vertical Curve Point (VPC), Vertical Curve #3
auto vpt3 = file.addDoublet<Schema::IfcCartesianPoint>(8400.0, 133.0); // Vertical Curve Tangent (VPT), Vertical Curve #3
auto vpc4 = file.addDoublet<Schema::IfcCartesianPoint>(9400.0, 113.0); // Vertical Curve Point (VPC), Vertical Curve #4
auto vpt4 = file.addDoublet<Schema::IfcCartesianPoint>(10200.0, 103.0); // Vertical Curve Tangent (VPT), Vertical Curve #4
auto vpoe = file.addDoublet<Schema::IfcCartesianPoint>(12800.0, 90.0); // ending
//
// Build the vertical alignment segments
//
// Grade start to VPC1
auto vertical_profile_segment_1 = create_gradient(file, vpob, 1.75 / 100, 1200);
vertical_curve_segments.push_back(vertical_profile_segment_1.first);
vertical_segments.push_back(vertical_profile_segment_1.second);
// Vertical Curve 1
auto vertical_profile_segment_2 = create_vcurve(file, vpc1, 1.75 / 100, -1.0 / 100, 1600);
vertical_curve_segments.push_back(vertical_profile_segment_2.first);
vertical_segments.push_back(vertical_profile_segment_2.second);
// Grade VPT1 to VPC2
auto vertical_profile_segment_3 = create_gradient(file, vpt1, -1.0 / 100, 1600);
vertical_curve_segments.push_back(vertical_profile_segment_3.first);
vertical_segments.push_back(vertical_profile_segment_3.second);
// Vertical Curve 2
auto vertical_profile_segment_4 = create_vcurve(file, vpc2, -1.0 / 100, 2.0 / 100, 1200);
vertical_curve_segments.push_back(vertical_profile_segment_4.first);
vertical_segments.push_back(vertical_profile_segment_4.second);
// Grade PVT2 to VPC3
auto vertical_profile_segment_5 = create_gradient(file, vpt2, 2.0 / 100, 800);
vertical_curve_segments.push_back(vertical_profile_segment_5.first);
vertical_segments.push_back(vertical_profile_segment_5.second);
// Vertical Curve 3
auto vertical_profile_segment_6 = create_vcurve(file, vpc3, 2.0 / 100, -2.0 / 100, 2000);
vertical_curve_segments.push_back(vertical_profile_segment_6.first);
vertical_segments.push_back(vertical_profile_segment_6.second);
// Grade PVT3 to VPC4
auto vertical_profile_segment_7 = create_gradient(file, vpt3, -2.0 / 100, 1000);
vertical_curve_segments.push_back(vertical_profile_segment_7.first);
vertical_segments.push_back(vertical_profile_segment_7.second);
// Vertical Curve 4
auto vertical_profile_segment_8 = create_vcurve(file, vpc4, -2.0 / 100, -0.5 / 100, 800);
vertical_curve_segments.push_back(vertical_profile_segment_8.first);
vertical_segments.push_back(vertical_profile_segment_8.second);
// Grade VPT4 to End
auto vertical_profile_segment_9 = create_gradient(file, vpt4, -0.5 / 100, 2600);
vertical_curve_segments.push_back(vertical_profile_segment_9.first);
vertical_segments.push_back(vertical_profile_segment_9.second);
// Zero-length terminator
auto vertical_terminator_segment = create_gradient(file, vpoe, -0.5 / 100, 0.0);
vertical_terminator_segment.first.setTransition(Schema::IfcTransitionCode::IfcTransitionCode_DISCONTINUOUS);
vertical_curve_segments.push_back(vertical_terminator_segment.first);
vertical_segments.push_back(vertical_terminator_segment.second);
//
// Create the vertical alignment (IfcAlignmentVertical) and nest alignment segments
//
auto vertical_profile = file.create<Schema::IfcAlignmentVertical>();
vertical_profile.setGlobalId(ifcopenshell::global_id());
vertical_profile.setName("Example Vertical Profile");
auto nests_vertical_segments = file.create<Schema::IfcRelNests>();
nests_vertical_segments.setGlobalId(ifcopenshell::global_id());
nests_vertical_segments.setName("Nests vertical alignment segments with vertical profile");
nests_vertical_segments.setRelatingObject(vertical_profile);
nests_vertical_segments.setRelatedObjects(vertical_segments);
//
// Create profile view axis model representation for the vertical profile
//
// start by defining a gradient curve composed of the vertical curve segments and associated with the horizontal composite curve
auto gradient_curve = file.create<Schema::IfcGradientCurve>();
gradient_curve.setSegments(vertical_curve_segments);
gradient_curve.setSelfIntersect(false);
gradient_curve.setBaseCurve(composite_curve);
// create the axis representation
auto axis3d_shape_representation = file.create<Schema::IfcShapeRepresentation>();
axis3d_shape_representation.setContextOfItems(axis_model_representation_subcontext);
axis3d_shape_representation.setRepresentationIdentifier("Axis");
axis3d_shape_representation.setRepresentationType("Curve3D");
// the gradient curve is a representation item
axis3d_shape_representation.setItems({gradient_curve});
// create axis representations for each segment
create_segment_representations(file, global_placement, axis_model_representation_subcontext, horizontal_curve_segments, horizontal_segments);
create_segment_representations(file, global_placement, axis_model_representation_subcontext, vertical_curve_segments, vertical_segments);
//
// Create the IfcAlignment
//
// create the alignment product definition
auto alignment_product = file.create<Schema::IfcProductDefinitionShape>();
alignment_product.setName("Alignment Product Definition Shape");
// the alignment has two representations, a plan view footprint and a 3d curve
alignment_product.setRepresentations({footprint_shape_representation, axis3d_shape_representation});
// create the alignment
auto alignment = file.create<Schema::IfcAlignment>();
alignment.setGlobalId(ifcopenshell::global_id());
alignment.setName("Example Alignment");
alignment.setObjectPlacement(global_placement);
alignment.setRepresentation(alignment_product);
// Nest the IfcAlignmentHorizontal and IfcAlignmentVertical with the IfcAlignment to complete the business logic
// 4.1.4.4.1 Alignments nest horizontal and vertical layouts
// https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/concepts/Object_Composition/Nesting/Alignment_Layouts/content.html
auto nests_alignment_layouts = file.create<Schema::IfcRelNests>();
nests_alignment_layouts.setGlobalId(ifcopenshell::global_id());
nests_alignment_layouts.setName("Nest horizontal and vertical alignment layouts with the alignment");
nests_alignment_layouts.setRelatingObject(alignment);
nests_alignment_layouts.setRelatedObjects({horizontal_alignment, vertical_profile});
// Define the relationship with the project
// IFC 4.1.4.1.1 "Every IfcAlignment must be related to IfcProject using the IfcRelAggregates relationship"
// https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/concepts/Object_Composition/Aggregation/Alignment_Aggregation_To_Project/content.html
// IfcProject <-> IfcRelAggregates <-> IfcAlignment
auto aggregate_alignments_with_project = file.create<Schema::IfcRelAggregates>();
aggregate_alignments_with_project.setGlobalId(ifcopenshell::global_id());
aggregate_alignments_with_project.setName("Alignments in project");
aggregate_alignments_with_project.setRelatingObject(project);
aggregate_alignments_with_project.setRelatedObjects({alignment});
// Define the spatial structure of the alignment with respect to the site
// IFC 4.1.5.1 alignment is referenced in spatial structure of an IfcSpatialElement. In this case IfcSite is the highest level IfcSpatialElement
// https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/HTML/concepts/Object_Connectivity/Alignment_Spatial_Reference/content.html
// IfcSite <-> IfcRelReferencedInSpatialStructure <-> IfcAlignment
// This means IfcAlignment is not part of the IfcSite (it is not an aggregate component) but instead IfcAlignment is used within
// the IfcSite by reference. This implies an IfcAlignment can traverse many IfcSite instances within an IfcProject
std::vector<Schema::IfcSpatialReferenceSelect> list_alignments_referenced_in_site{alignment};
// this alignment traverse 3 bridge sites.
for (int i = 1; i <= 3; i++) {
std::ostringstream os;
os << "Site of Bridge " << i;
auto site = file.addSite(project);
site.setName(os.str());
std::ostringstream description;
description << "Alignments referenced into the spatial structure of Bridge Site " << i;
auto rel_referenced_in_spatial_structure = file.create<Schema::IfcRelReferencedInSpatialStructure>();
rel_referenced_in_spatial_structure.setGlobalId(ifcopenshell::global_id());
rel_referenced_in_spatial_structure.setDescription(description.str());
rel_referenced_in_spatial_structure.setRelatedElements(list_alignments_referenced_in_site);
rel_referenced_in_spatial_structure.setRelatingStructure(site);
}
// That's it - save the model to a file
std::ofstream ofs("FHWA_Bridge_Geometry_Alignment_Example.ifc");
ofs << file;
}
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