IfcSweptDiskSolidPolygonal

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcSweptDiskSolidPolygonal			ADDED

Semantic definitions at the entity

Entity definition

The IfcSweptDiskSolidPolygonal is a IfcSweptDiskSolid where the Directrix is restricted to be provided by an poly line only. An optional FilletRadius attribute can be asserted, it is then applied as a fillet to all transitions between the segments of the poly line.

NOTE The geometric item IfcIndexedPolyCurve provides a more compact representation compared with IfcPolyline. Therefore it is the prefered curve representation for the Directrix. The IfcIndexedPolyCurve shall not have Segments defined, resticting it to a poly line only.

HISTORY New entity in IFC4.

Informal Propositions:

The FilletRadius, if provided, has to be smaller then or equal to the length of the start and end segment of the IfcPolyline, and smaller then or equal to one half of the lenght of the shortest inner segment.

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
6	FilletRadius	IfcPositiveLengthMeasure	?	The fillet that is equally applied to all transitions between the segments of the IfcPolyline, providing the geometric representation for the Directrix. If omited, no fillet is applied to the segments.	X

Formal Propositions

Rule	Description
CorrectRadii	If a FilletRadius is given, it has to be greater or equal to the Radius of the disk.
DirectrixIsPolyline	The Directrix shall be of type IfcIndexedPolyCurve with no Segments, or of type IfcPolyline.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRepresentationItem
	LayerAssignment	IfcPresentationLayerAssignment @AssignedItems	S[0:1]	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.	X
	StyledByItem	IfcStyledItem @Item	S[0:1]	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.	X
IfcGeometricRepresentationItem
IfcSolidModel
	Dim :=3	IfcDimensionCount		The space dimensionality of this class, it is always 3.	X
IfcSweptDiskSolid
1	Directrix	IfcCurve		The curve used to define the sweeping operation. The solid is generated by sweeping a circular disk along the Directrix.	X
2	Radius	IfcPositiveLengthMeasure		The Radius of the circular disk to be swept along the directrix. Denotes the outer radius, if an InnerRadius is applied.	X
3	InnerRadius	IfcPositiveLengthMeasure	?	This attribute is optional, if present it defines the radius of a circular hole in the centre of the disk.	X
4	StartParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation commences. If no value is provided the start of the sweeping operation is at the start of the Directrix.. IFC4 CHANGE The attribute has been changed to OPTIONAL with upward compatibility for file-based exchange.	X
5	EndParam	IfcParameterValue	?	The parameter value on the Directrix at which the sweeping operation ends. If no value is provided the end of the sweeping operation is at the end of the Directrix.. IFC4 CHANGE The attribute has been changed to OPTIONAL with upward compatibility for file-based exchange.	X
IfcSweptDiskSolidPolygonal
6	FilletRadius	IfcPositiveLengthMeasure	?	The fillet that is equally applied to all transitions between the segments of the IfcPolyline, providing the geometric representation for the Directrix. If omited, no fillet is applied to the segments.	X

Formal representations

XML Specification

 <xs:element name="IfcSweptDiskSolidPolygonal" type="ifc:IfcSweptDiskSolidPolygonal" substitutionGroup="ifc:IfcSweptDiskSolid" nillable="true"/>

 <xs:complexType name="IfcSweptDiskSolidPolygonal">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSweptDiskSolid">

    <xs:attribute name="FilletRadius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcSweptDiskSolidPolygonal

 SUBTYPE OF (IfcSweptDiskSolid);

  FilletRadius : OPTIONAL IfcPositiveLengthMeasure;

 WHERE

  CorrectRadii : NOT(EXISTS(FilletRadius)) OR (FilletRadius >= SELF\IfcSweptDiskSolid.Radius);
  DirectrixIsPolyline : ('IFCGEOMETRYRESOURCE.IfcPolyline' IN TYPEOF(SELF\IfcSweptDiskSolid.Directrix)) OR

(('IFCGEOMETRYRESOURCE.IfcIndexedPolyCurve' IN TYPEOF(SELF\IfcSweptDiskSolid.Directrix)) AND NOT(EXISTS(SELF\IfcSweptDiskSolid.Directrix.Segments)));
END_ENTITY;

 EXPRESS-G diagram

	Festkörper - Entlang einer Polylinie extrudierte Kreisscheibe
	Swept Disk Solid Polygonal