8.9.3.15 IfcCartesianTransformationOperator2DnonUniform

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AbV ⓘ

8.9.3.15.1 Semantic definition

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:

SELF\IfcCartesianTransformationOperator.Scale: the x axis scale factor
Scale2: the y axis scale factor

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).

8.9.3.15.2 Entity inheritance

8.9.3.15.3 Attributes

#	Attribute	Type	Description
IfcRepresentationItem (2)
	LayerAssignment	SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems	Assignment 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.
IfcCartesianTransformationOperator (6)
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	IfcReal	This attribute is formally derived. `NVL(Scale, 1.0)` The derived scale S of the transformation, equal to scale if that exists, or 1.0 otherwise.
*	Dim	IfcDimensionCount	This attribute is formally derived. `LocalOrigin.Dim` The space dimensionality of this class, determined by the space dimensionality of the local origin.
IfcCartesianTransformationOperator2D (1)
*	U	LIST [2:2] OF IfcDirection	This attribute is formally derived. `IfcBaseAxis(2,SELF\IfcCartesianTransformationOperator.Axis1, SELF\IfcCartesianTransformationOperator.Axis2,?)` 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.
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IfcCartesianTransformationOperator2DnonUniform (2)
5	Scale2	OPTIONAL IfcReal	The scaling value specified for the transformation along the axis 2. This is normally the y scale factor.
*	Scl2	IfcReal	This attribute is formally derived. `NVL(Scale2, SELF\IfcCartesianTransformationOperator.Scl)` 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.

Table 8.9.3.15.A

8.9.3.15.4 Formal propositions

Name	Description
Scale2GreaterZero	The derived scaling Scl2 shall be greater than zero.
`Scl2 > 0.0`

Table 8.9.3.15.B

8.9.3.15.5 Formal representation

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