Represent 2D Space Footprint

Overview

Provides the 2D plan shape of a spatial structure for any circumstance where a 2D boundary shape or footprint is required. The following are some typical situations where it would be used. The list is not exhaustive; other uses may be relevant:

establish the boundary of a site
determine the limiting area of a survey or terrain
fix the 2 dimensional shape where a building meets the ground
fix the 2 dimensional projected shape of a roof structure onto the ground

Results

xxx

Description	Entity/Pset/Functional Part	MAN	REC	OPT
Determine the shape representation of the spatial structure under consideration. Plan shape of a site/external space, building, building storey or room space (including both _whole and part rooms where there is a need to separately identify a part room as a space).	IfcShapeRepresentation
Determine the required geometric representation context of the shape representation. The representation context identifier may be specified. Then representation context type should be specified according to the circumstances in which the functional part is being used. Context type should be established by agreement between implementers and should	fp_geometric_representation_context
The shape representation is one of the representations that can be defined through the inherited IfcProduct.ProductRepresentation (which can comprise a list of representations)	IfcProduct.ProductRepresentation
Set the representation identifier for the shape For a 2D footprint, the value of the shape representation identifier must be asserted and should be set to 'Footprint'	IfcShapeRepresentation.RepresentationIdentifier where RepresentationIdentifier = 'Footprint'
Set the representation type for the shape The type of the shape representation must be asserted and should be set using the attribute 'RepresentationType' such that IfcShapeRepresentation.RepresentationType = 'Curve2D' or 'GeometricCurveSet'	IfcShapeRepresentation.RepresentationType where either RepresentationType = 'Curve2D' RepresentationType = 'GeometricCurveSet'
Determine the geometric items that make up the shape representation. The 2D spatial shape may be geometrically described as a single 2D curve (such as IfcPolyline or IfcCompositeCurve), or by a list of 2D curves (in case of inner boundaries).	IfcShapeRepresentation.RepresentationItems IfcPolyline IfcCompositeCurve
For a polyline
Set the points that define the polyline	IfcPolyline.Points::IfcCartesianPoint
For a composite curve
Determine the segments of the composite curve Segments are ordered as a list	IfcCompositeCurve.Segments::IfcCompositeCurveSegment
Assert whether the curve self intersects A curve self intersects if it turns around and crosses over itself. For a footprint representation, curves should not self intersect and the value should be set to FALSE. However, within IFC, this value although required is only for information	IfcCompositeCurve.SelfIntersect where (expected value) SelfIntersect = .FALSE.
Derive the number of segments in the curve and if the curve is closed These values are derived automatically from the number of segment occurrences in the list of IfcCompositeCurve.Segments and the transition code of the segments.	IfcCompositeCurve.NSegments IfcCompositeCurve.ClosedCurve
Determine the transition of each segment within the footprint. Generally, segments within a footprint will have a continuous transition with the same gradient.	IfcCompositeCurveSegment.Transition::TransitionCode
Set the sense of the segment The sense of the segment determines its start to end direction compared to that of te complete composite curve (parent curve) of which it forms a part. It may be either the same (TRUE) or not (FALSE). For a 2D footprint, all segments should be normalised so that the sense is the same although applications may be able to handle segments with a different sense.	IfcCompositeCurveSegment.SameSense where (typically) SameSense = .TRUE.
Assign the segment to the parent curve This attribute makes a relationship between the segment and the curve of which it forms a part. The parent curve should be an occurrence of IfcCompositeCurve. NOTE that the target of this attribute is IfcBoundedCurve in the IFC model but for this functional part, it is interpreted that it should be an IfcCompositeCurve.	IfcCompositeCurveSegment.ParentCurve::IfcCompositeCurve
Set the space dimensionality of the curve Note that the dimensionality is set for either the polyline or composite curve as a subtype of IfcCurve and not at the abstract IfcCurve supertype.	IfcCurve.Dim

Page Operations

Browse Space

Represent 2D Space Footprint

Overview

Results