IFC 4.3.x development

8.9.3.12 IfcCartesianPoint

Change log

IFC4

additionswhere_rulesCP2Dor3D
deletionswhere_rulesWR1

8.9.3.12.1 Semantic definitions at the entity

An IfcCartesianPoint defines a point by coordinates in an orthogonal, right-handed Cartesian coordinate system. For the purpose of this specification only two and three dimensional Cartesian points are used.

NOTE  Definition according to ISO/CD 10303-42:1992
A cartesian_point is a point defined by its coordinates in a rectangular Cartesian coordinate system, or in a parameter space. The entity is defined in a one, two or three-dimensional space as determined by the number of coordinates in the list. Depending upon the geometric representation context in which the point is used the names of the coordinates may be (x,y,z), or (u,v), or any other chosen values.

NOTE  Entity adapted from cartesian_point defined in ISO 10303-42

HISTORY  New entity in IFC1.0

8.9.3.12.1 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
IfcPoint
IfcCartesianPoint
1 Coordinates LIST [1:3] OF IfcLengthMeasure The first, second, and third coordinate of the point location. If placed in a two or three dimensional rectangular Cartesian coordinate system, Coordinates[1] is the X coordinate, Coordinates[2] is the Y coordinate, and Coordinates[3] is the Z coordinate.
Dim INVALID The space dimensionality of this class, determined by the number of coordinates in the List of Coordinates.

8.9.3.12.2 Entity inheritance

dot_inheritance IfcCartesianPoint IfcCartesianPoint IfcPoint IfcPoint IfcCartesianPoint->IfcPoint IfcPoint_children 3 more... IfcPoint_children->IfcPoint IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcPoint->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.9.3.12.3 Formal representations

ENTITY IfcCartesianPoint
 SUBTYPE OF (IfcPoint);
	Coordinates : LIST [1:3] OF IfcLengthMeasure;
 DERIVE
	 Dim : IfcDimensionCount := HIINDEX(Coordinates);
 WHERE
	CP2Dor3D : HIINDEX(Coordinates) >= 2;
END_ENTITY;