|Form - Repräsentation|
|Représentation de forme|
The IfcShapeRepresentation represents the concept of a particular
geometric representation of a product or a product component within a specific
geometric representation context. The inherited attribute
RepresentationType is used to define the geometric model used for the
shape representation (e.g. 'SweptSolid', or 'Brep'), the inherited attribute
RepresentationIdentifier is used to denote the kind of the
representation captured by the IfcShapeRepresentation (e.g. 'Axis',
Several representation identifiers for shape representation are included as predefined values for RepresentationIdentifier. Table 696 indicates the defined list of values for RepresentationIdentifier.
Table 696 — Representation identifiers
Several representation types for shape representation are included as predefined values for RepresentationType. Table 697 indicates the defined list of values for RepresentationType.
Table 697 — Representation types
NOTE The definition relates to shape_representation defined in ISO 10303-41.
HISTORY New entity in IFC1.5.
IFC4 CHANGE The RepresentationType's 'Point', 'PointCloud', 'Curve', 'Curve3D', 'Surface', 'Surface2D', 'Surface3D', 'FillArea', 'Text', 'Tessellation', 'AdvancedBrep', 'LightSource', and the RepresentationIdentifier 'Body-FallBack', 'Profile', 'Clearance', 'Lighting' have been added.
|CorrectContext||The context to which the IfcShapeRepresentation is assign, shall be of type IfcGeometricRepresentationContext.|
|NoTopologicalItem||No topological representation item shall be directly used for shape representations, with the exception of IfcVertexPoint, IfcEdgeCurve, IfcFaceSurface.|
|HasRepresentationType||A representation type should be provided for the shape representation.|
|CorrectItemsForType||Checks the proper use of Items according to the RepresentationType.|
|HasRepresentationIdentifier||A representation identifier should be provided for the shape representation.|
|1||ContextOfItems||IfcRepresentationContext||[1:1]||Definition of the representation context for which the different subtypes of representation are valid.||X|
|2||RepresentationIdentifier||IfcLabel||[0:1]||The optional identifier of the representation as used within a project.||X|
The description of the type of a representation context. The representation type defines the type of geometry or topology used for representing the product representation. More information is given at the subtypes IfcShapeRepresentation and IfcTopologyRepresentation.|
The supported values for context type are to be specified by implementers agreements.
|4||Items||IfcRepresentationItem||S[1:?]||Set of geometric representation items that are defined for this representation.||X|
|S[0:1]||Use of the representation within an IfcRepresentationMap. If used, this IfcRepresentation may be assigned to many representations as one of its Items using an IfcMappedItem. Using IfcRepresentationMap is the way to share one representation (often of type IfcShapeRepresentation) by many products.||X|
|S[0:?]||Assignment of the whole representation to a single or multiple layer(s). The LayerAssigments can be overridden by LayerAssigments of the IfcRepresentationItem's within the list of Items.
NOTE Implementation agreements can restrict the maximum number of layer assignments to 1.
|S[0:?]||Reference to the product representations to which this individual representation applies. In most cases it is the reference to one or many product shapes, to which this shape representation is applicable.||X|
|S[0:1]||Reference to the shape aspect, for which it is the shape representation.||X|
SUBTYPE OF (IfcShapeModel);
CorrectContext : 'IFCREPRESENTATIONRESOURCE.IFCGEOMETRICREPRESENTATIONCONTEXT' IN TYPEOF(SELF\IfcRepresentation.ContextOfItems);
NoTopologicalItem : SIZEOF(QUERY(temp <* Items | ('IFCTOPOLOGYRESOURCE.IFCTOPOLOGICALREPRESENTATIONITEM' IN TYPEOF(temp)) AND (NOT(SIZEOF( ['IFCTOPOLOGYRESOURCE.IFCVERTEXPOINT', 'IFCTOPOLOGYRESOURCE.IFCEDGECURVE', 'IFCTOPOLOGYRESOURCE.IFCFACESURFACE'] * TYPEOF(temp)) = 1)) )) = 0;
HasRepresentationType : EXISTS(SELF\IfcRepresentation.RepresentationType);
CorrectItemsForType : IfcShapeRepresentationTypes(SELF\IfcRepresentation.RepresentationType, SELF\IfcRepresentation.Items);
HasRepresentationIdentifier : EXISTS(SELF\IfcRepresentation.RepresentationIdentifier);
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