Navigate Navigate Navigate Navigate Navigate Navigate Navigate Navigate


Definition from buildingSMART: A physical quantity, IfcQuantityLength, that defines a derived length measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.

EXAMPLE: A rafter within a roof construction may be measured according to its length (taking a common cross section into account). The actual size of the length depends on the method of measurement used.

HISTORY New entity in IFC Release 2.x . It replaces the calcXxx attributes used in previous IFC Releases.

EXPRESS specification:

ENTITY IfcQuantityLength
SUBTYPE OF ( IfcPhysicalSimpleQuantity);
LengthValue  :  IfcLengthMeasure;
WR21  :  NOT(EXISTS(SELF\IfcPhysicalSimpleQuantity.Unit)) OR (SELF\IfcPhysicalSimpleQuantity.Unit.UnitType = IfcUnitEnum.LENGTHUNIT);
WR22  :  LengthValue >= 0.;

Attribute definitions:

LengthValue  :  Length measure value of this quantity.

Formal Propositions:

WR21  :  If a unit is given, the unit type shall be a length unit.
WR22  :  A valid length quantity shall be greater than or equal to zero.

Inheritance graph

ENTITY IfcQuantityLength;
ENTITY IfcPhysicalQuantity;
Name  :  IfcLabel;
Description  :  OPTIONAL IfcText;
PartOfComplex  :  SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities;
ENTITY IfcPhysicalSimpleQuantity;
Unit  :  OPTIONAL IfcNamedUnit;
ENTITY IfcQuantityLength;
LengthValue  :  IfcLengthMeasure;