IFC 4.3.x development

8.9.3.15 IfcCartesianTransformationOperator2DnonUniform

Change log

IFC4

additions where_rules Scale2GreaterZero
deletions where_rules WR1
modificationsattributes Scale2 definitionChanged from real to IfcReal

8.9.3.15.1 Semantic definitions at the entity

A Cartesian transformation operator 2d non uniform defines a geometric transformation in two-dimensional space composed of translation, rotation, mirroring and non uniform scaling. Non uniform scaling is given by two different scaling factors:

If the Scale factor (at supertype IfcCartesianTransformationOperator) is omitted, it defaults to 1.0. If the Scale2 factor is omitted, it defaults to the value of Scale (the x axis scale factor).

NOTE  The scale factor (Scl) defined at the supertype IfcCartesianTransformationOperator is used to express the calculated Scale factor (normally x axis scale factor).

HISTORY  New entity in IFC2x.

8.9.3.15.1 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
IfcCartesianTransformationOperator
1 Axis1 OPTIONAL IfcDirection The direction used to determine U[1], the derived X axis direction.
2 Axis2 OPTIONAL IfcDirection The direction used to determine U[2], the derived Y axis direction.
3 LocalOrigin IfcCartesianPoint The required translation, specified as a cartesian point. The actual translation included in the transformation is from the geometric origin to the local origin.
4 Scale OPTIONAL IfcReal The scaling value specified for the transformation.
Scl INVALID The derived scale S of the transformation, equal to scale if that exists, or 1.0 otherwise.
Dim INVALID The space dimensionality of this class, determined by the space dimensionality of the local origin.
IfcCartesianTransformationOperator2D
U INVALID The list of mutually orthogonal, normalized vectors defining the transformation matrix T. They are derived from the explicit attributes Axis1 and Axis2 in that order.
IfcCartesianTransformationOperator2DnonUniform
5 Scale2 OPTIONAL IfcReal The scaling value specified for the transformation along the axis 2. This is normally the y scale factor.
Scl2 INVALID The derived scale S(2) of the transformation along the axis 2 (normally the y axis), equal to Scale2 if that exists, or equal to the derived Scl1 (normally the x axis scale factor) otherwise.

8.9.3.15.2 Entity inheritance

dot_inheritance IfcCartesianTransformationOperator2DnonUniform IfcCartesianTransformationOperator2DnonUniform IfcCartesianTransformationOperator2D IfcCartesianTransformationOperator2D IfcCartesianTransformationOperator2DnonUniform->IfcCartesianTransformationOperator2D IfcCartesianTransformationOperator IfcCartesianTransformationOperator IfcCartesianTransformationOperator2D->IfcCartesianTransformationOperator IfcCartesianTransformationOperator3D IfcCartesianTransformationOperator3D IfcCartesianTransformationOperator3D->IfcCartesianTransformationOperator IfcGeometricRepresentationItem IfcGeometricRepresentationItem IfcCartesianTransformationOperator->IfcGeometricRepresentationItem IfcGeometricRepresentationItem_children 24 more... IfcGeometricRepresentationItem_children->IfcGeometricRepresentationItem IfcRepresentationItem IfcRepresentationItem IfcGeometricRepresentationItem->IfcRepresentationItem IfcRepresentationItem_children 3 more... IfcRepresentationItem_children->IfcRepresentationItem

8.9.3.15.3 Formal representations

ENTITY IfcCartesianTransformationOperator2DnonUniform
 SUBTYPE OF (IfcCartesianTransformationOperator2D);
	Scale2 : OPTIONAL IfcReal;
 DERIVE
	 Scl2 : IfcReal := NVL(Scale2, SELF\IfcCartesianTransformationOperator.Scl);
 WHERE
	Scale2GreaterZero : Scl2 > 0.0;
END_ENTITY;