IFC 4.3.x development

8.9.3.23 IfcConic

8.9.3.23.1 Semantic definitions at the entity

An IfcConic is a parameterized planar curve.

NOTE  Definition according to ISO/CD 10303-42:1992
A conic is a planar curve which could be produced by intersecting a plane with a cone. A conic is defined in terms of its intrinsic geometric properties rather than being described in terms of other geometry. A conic entity always has a placement coordinate system defined by axis2_placement; the parametric representation is defined in terms of this placement coordinate system.

NOTE Entity adapted from conic defined in ISO 10303-42

HISTORY  New entity in IFC1.0

8.9.3.23.1 Attributes

# Attribute Type Description
IfcRepresentationItem
LayerAssignmentSET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItemsAssignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.

> IFC2x3 CHANGE  The inverse attribute LayerAssignments has been added.

> IFC4 CHANGE  The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
StyledByItem SET [0:1] OF IfcStyledItem FOR Item Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.



> IFC2x3 CHANGE  The inverse attribute StyledByItem has been added.
IfcGeometricRepresentationItem
IfcCurve
Dim INVALID The space dimensionality of this abstract class, defined differently for all subtypes, i.e. for IfcLine, IfcConic and IfcBoundedCurve.
IfcConic
1 Position IfcAxis2Placement The location and orientation of the conic. Further details of the interpretation of this attribute are given for the individual subtypes."

8.9.3.23.2 Entity inheritance

dot_inheritance IfcCircle IfcCircle IfcConic IfcConic IfcCircle->IfcConic IfcCurve IfcCurve IfcConic->IfcCurve IfcEllipse IfcEllipse IfcEllipse->IfcConic IfcCurve_children 7 more... IfcCurve_children->IfcCurve IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcCurve->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.9.3.23.3 Formal representations

ENTITY IfcConic
 ABSTRACT SUPERTYPE OF (ONEOF
	(IfcCircle
	,IfcEllipse))
 SUBTYPE OF (IfcCurve);
	Position : IfcAxis2Placement;
END_ENTITY;