IFC 4.3.x development

8.9.2.7 IfcDimensionCount

8.9.2.7.1 Semantic definitions at the entity

The IfcDimensionCount defines the dimensionality of the coordinate space. It is restricted to have the dimensionality of either 1, 2, or 3 for the purpose of this specification.

NOTE  The shape representations assigned to a geometric representation context may include geometric representation items of lower dimensionality, particularly when defining the boundary of planar surfaces as 2D cross sections for the purpose of 3D swept areas.

NOTE  Definition according to ISO/CD 10303-42:1992
A dimension count is a positive integer used to define the coordinate space dimensionality.

NOTE  Type adapted from dimension_count defined in ISO 10303-42.

HISTORY  New Type in IFC1.5

Formal Propositions

WR1

The dimension count should be an integer between 1 and 3 NOTE: This is a further constraint by IFC, the upper limit does not exist in STEP.

8.9.2.7.1 Formal representations

TYPE IfcDimensionCount = INTEGER;
 WHERE
	 WR1 : { 0 < SELF <= 3 };
END_TYPE;