Annex E
(informative)

Examples

E.7.2 - Geographic Referencing Rigid Operation

Example overview

This file is model in as adaption of one of the examples in Jaud et al. (2022) 'Georeferencing in IFC: meeting the requirements of infrastructure and building industries' https://www.isprs-ann-photogramm-remote-sens-spatial-inf-sci.net/X-4-W2-2022/145/2022/ and uses IfcGeographicCRS in conjunction with IfcRigidOperation.

IFC-SPF source

ISO-10303-21;
HEADER;
FILE_DESCRIPTION (('ViewDefinition[Alignment-basedReferenceView]'), '2;1');
FILE_NAME ('geographic-referencing-rigid-operation.ifc', '2022-11-16T10:37:00', (), (), 'redacted', 'redacted', $);
FILE_SCHEMA (('IFC4X3_DEV_7e95fe8'));
ENDSEC;
DATA;

/*The basis definitions of an IfcProject and IfcGeometricRepresentationContext */
#1=IFCPROJECT('2DAvEupIz0HQr73cMaawtY',$, 'Project name', $, $, $, $, (#21), #11);
#2=IFCDIRECTION((1., 0., 0.));
#4=IFCDIRECTION((0., 0., 1.));
#5=IFCCARTESIANPOINT((0., 0., 0.));
#7=IFCDIRECTION((0.,1.));
#11=IFCUNITASSIGNMENT((#12, #15));
#12=IFCSIUNIT(*, .LENGTHUNIT., $, .METRE.);
#13=IFCSIUNIT(*, .PLANEANGLEUNIT., $, .RADIAN.);
#14=IFCMEASUREWITHUNIT(IFCPLANEANGLEMEASURE(0.017453292519943295), #13);
#15=IFCCONVERSIONBASEDUNIT(#16,.PLANEANGLEUNIT., 'degree', #14);
#16=IFCDIMENSIONALEXPONENTS(0, 0, 0, 0, 0, 0, 0);
#21=IFCGEOMETRICREPRESENTATIONCONTEXT($,'Model', 3, 1.E-6, #22, #7);
#22=IFCAXIS2PLACEMENT3D(#5, #4, #2);

/* Georeferencing data of an IFC dataset in a Geographic CRS. The site with this context lies at the Bell tower on the island of Lake Bled in Slovenia.*/
#301=IFCGEOGRAPHICCRS('EPSG:4258', 'ETRS89', 'EPSG:6258', 'EPSG:8901', #15, #12);
#302=IFCRIGIDOPERATION(#21, #301, IFCPLANEANGLEMEASURE(14.0902217), IFCPLANEANGLEMEASURE(46.3623297), 475.);


/* IfcSite definition*/
#30 = IFCSITE('27H$neCQf1NwtmczxBInPR', $, $, $, $, #31, $, $, .ELEMENT., $, $, $, $, $);
/* IfcSite's placement is the top-most placement and uses the same IfcAxis2Placement as IfcGeometricRepresentationContext does */
#31 = IFCLOCALPLACEMENT($, #22);
/* Relationship between Project and Site */
#33 = IFCRELAGGREGATES('3Hu7f6BmT14B_XS9yS78Jr', $, $, $, #1, (#30));


/* Definition of a Footprint */
#40 = IFCBUILTELEMENT('28H$neCQf1NwtmczxBInPR', $, 'Footprint', $, $, #50, #60, $);
/* Relationship: Footprint in Site */
#41 = IFCRELCONTAINEDINSPATIALSTRUCTURE('3Uu7sw3ALEWKTWNPpz$fqn', $, 'Container', 'Container to Contained', (#40), #30);
/* Placement of the Footprint, relative to that of IfcSite. The way it is modelled, there is no offset and no rotation. */
#50 = IFCLOCALPLACEMENT(#31, #22);
/* Representation of the Footprint: a polyline with six points */
#60= IFCPRODUCTDEFINITIONSHAPE($,$,(#61));
#61= IFCSHAPEREPRESENTATION(#21,'Axis','Curve2D',(#62));
#62= IFCPOLYLINE((#63,#64,#67,#68,#65,#66,#63));
#63 = IFCCARTESIANPOINT((32.58,3.68));
#64 = IFCCARTESIANPOINT((31.82,9.10));
#65 = IFCCARTESIANPOINT((28.26,0.37));
#66 = IFCCARTESIANPOINT((27.95,2.90));
#67 = IFCCARTESIANPOINT((17.37,6.98));
#68 = IFCCARTESIANPOINT((18.67,-1.02));


/* Definition of a Cube*/
#70= IFCBUILTELEMENT('1kTvXnbbzCWw8lcMd1dR4o',$,'Cube',$,$,#80,#90,$);
/* Relationship: Cube in Site */
#71=IFCRELCONTAINEDINSPATIALSTRUCTURE('2TnxZkTXT08eDuMuhUUFNy',$,'Container','Container to Contained',(#70),#30);
/* Placement of the cube, relative to that of IfcSite. */
#80= IFCLOCALPLACEMENT(#31,#81);
/* Set local placement to 1 meter on x-axis, and 0 on y and z axes, no rotation. z and x axes are set to '$' and therefore identical to those of Site */ 
#81= IFCAXIS2PLACEMENT3D(#82,$,$);
#82= IFCCARTESIANPOINT((1.,0.,0.));
/* Representation of the Cube: a single swept solid shape */
#90= IFCPRODUCTDEFINITIONSHAPE($,$,(#91));
#91= IFCSHAPEREPRESENTATION(#21,'Body','SweptSolid',(#92));
/* based on a profile (or cross section) of 3m by 4m being extruded by 1.5m */
#92= IFCEXTRUDEDAREASOLID(#93,$,#4,1.5);
#93= IFCRECTANGLEPROFILEDEF(.AREA.,'3m x 4m rectangle',$,3.,4.);
/* extrusion body is placed centric with no rotation inside the object coordinate placement */
/* extrusion position z = default = (0.,0.,1.), x = default = (1.,0.,0.) */
/* the default position, i.e. no re-positioning of the results, hence the position is NIL */
/* the extrusion is perpendicular to the profile - i.e. along the positive z-axis */
ENDSEC;
END-ISO-10303-21;