Defined in File Ifc4x3_rc1.h
IfcEllipseProfileDef: public Ifc4x3_rc1::IfcParameterizedProfileDef¶
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 317 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.
Figure 317 — Ellipse profile
The first radius of the ellipse. It is measured along the direction of Position.P.
The second radius of the ellipse. It is measured along the direction of Position.P.