Link to this pageRelease Candidate 3 completes the alignment and geometry definitions for infrastructure. It is anticipated to be the final release candidate before the official publication of IFC 4.1.
A new general transition curve type IfcTransitionCurveSegment2D may be used to define various transitions between straight segments and circular arcs, and deprecates IfcClothoidalArcSegment2D.
A new geometric curve type IfcOffsetCurveByDistances may be used to define "string lines" having variable lateral and vertical offsets relative to a parent alignment curve, supporting super-elevations of roads and railways.
A new placement structure IfcLinearPlacement enables physical and spatial objects to be positioned along alignment curves or derivate string line curves.
A new data structure IfcCartesianPointList2DLabelled enables cross-sections to be defined where individual points are associated with string lines, to define geometry where the cross-section varies along an alignment.
A new geometric solid type IfcSectionedSolidHorizontal may be used to define swept solids for road surfaces or bridge decks with control over the orientation of cross-sections.
A new tessellated geometry type IfcTriangulatedIrregularNetwork may be used to efficiently define terrain surfaces with breaklines, holes, and voids.