IfcCartesianPoint

Definition from ISO/CD 10303-42:1992: A point defined by its coordinates in a two or three dimensional rectangular Cartesian coordinate system, or in a two dimensional parameter space. The entity is defined in a two or three dimensional space.

Definition from IAI: The derived attribute Dim has been added (see also note at IfcGeometricRepresentationItem). The WR1 was added to constrain the usage of IfcCartesianPoint in the context of IFC geometry. For the purpose of defining geometry in IFC only two and three dimensional Cartesian points are used.

NOTE: Corresponding STEP entity : cartesian_point, please refer to ISO/IS 10303-42:1994, p. 23 for the final definition of the formal standard.

HISTORY: New entity in IFC Release 1.0

EXPRESS specification:

ENTITY IfcCartesianPoint

SUBTYPE OF (

IfcPoint);

Coordinates

LIST [1:3] OF IfcLengthMeasure;

DERIVE

Dim

IfcDimensionCount := HIINDEX(Coordinates);

WHERE

WR1

HIINDEX(Coordinates) >= 2;

END_ENTITY;

Attribute definitions:

Coordinates	:	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	:	The space dimensionality of this class, determined by the number of coordinates in the List of Coordinates.

Formal Propositions:

WR1

Only two or three dimensional points shall be used for the purpose of defining geometry in this IFC Resource.

Inheritance graph

ENTITY IfcCartesianPoint;

ENTITY IfcRepresentationItem;

INVERSE

LayerAssignments

SET OF IfcPresentationLayerAssignment FOR AssignedItems;

StyledByItem

SET [0:1] OF IfcStyledItem FOR Item;

ENTITY IfcGeometricRepresentationItem;