IFC 4.3.x development IfcEllipseProfileDef Semantic definitions at the entity

IfcEllipseProfileDef defines an ellipse as the profile definition used by the swept surface geometry or the swept area solid. It is given by its semi axis attributes and placed within the 2D position coordinate system, established by the Position attribute.

HISTORY  New entity in IFC2x

Figure 1 illustrates parameters for the ellipse profile definition. The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept surface or swept area solid that uses the profile definition. It is the xy plane of either:

Or in case of sectioned spines it is the xy plane of each list member of IfcSectionedSpine.CrossSectionPositions. By using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (for example, upper-left bound). The location of the position coordinate system defines the center of the ellipse. The SemiAxis1 attribute defines the first radius of the ellipse in the direction of the X axis, the SemiAxis2 attribute defines the second radius of the ellipse in the direction of the Y axis.

NOTE  The semi axes of the ellipse are rectangular to each other by definition.

"ellipse profile" Attributes

# Attribute Type Description
1 ProfileType IfcProfileTypeEnum Defines the type of geometry into which this profile definition shall be resolved, either a curve or a surface area. In case of curve the profile should be referenced by a swept surface, in case of area the profile should be referenced by a swept area solid.
2 ProfileName OPTIONAL IfcLabel Human-readable name of the profile, for example according to a standard profile table. As noted above, machine-readable standardized profile designations should be provided in _IfcExternalReference.ItemReference_.
HasExternalReferenceSET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjectsReference to external information, e.g. library, classification, or document information, which is associated with the profile.

> IFC4 CHANGE New inverse attribute
HasProperties SET [0:?] OF IfcProfileProperties FOR ProfileDefinition Additional properties of the profile, for example mechanical properties.

> IFC4 CHANGE New inverse attribute
3 Position OPTIONAL IfcAxis2Placement2D Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied.
4 SemiAxis1 IfcPositiveLengthMeasure The first radius of the ellipse. It is measured along the direction of Position.P[1].
5 SemiAxis2 IfcPositiveLengthMeasure The second radius of the ellipse. It is measured along the direction of Position.P[2]. Entity inheritance

dot_inheritance IfcEllipseProfileDef IfcEllipseProfileDef IfcParameterizedProfileDef IfcParameterizedProfileDef IfcEllipseProfileDef->IfcParameterizedProfileDef IfcParameterizedProfileDef_children 10 more... IfcParameterizedProfileDef_children->IfcParameterizedProfileDef IfcProfileDef IfcProfileDef IfcParameterizedProfileDef->IfcProfileDef IfcProfileDef_children 5 more... IfcProfileDef_children->IfcProfileDef Definitions applying to General Usage Property Sets for Objects

'Pset_ProfileMechanical' Formal representations

ENTITY IfcEllipseProfileDef
 SUBTYPE OF (IfcParameterizedProfileDef);
	SemiAxis1 : IfcPositiveLengthMeasure;
	SemiAxis2 : IfcPositiveLengthMeasure;