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IfcShapeAspect

Definition from ISO/CD 10303-42:1992: The shape aspect is an identifiable element of the shape of a product.

Definition from IAI: The IfcShapeAspect allows for grouping of shape representation items that represent aspects (or components) of the shape of a product. Thereby shape representations of components of the product shape representing a distinctive part to a product that can be explicitly addressed.

NOTE: The definition of this class relates to the STEP entity shape_aspect. Please refer to ISO/IS 10303-41:1994 for the final definition of the formal standard.
ISSUE: See issue and change log for changes made in IFC Release 1.5 and IFC 2x.
HISTORY: New Entity in IFC Release 2.0

EXPRESS specification:

ENTITY IfcShapeAspect;
ShapeRepresentations  :  LIST [1:?] OF IfcShapeRepresentation;
Name  :  OPTIONAL IfcLabel;
Description  :  OPTIONAL IfcText;
ProductDefinitional  :  LOGICAL;
PartOfProductDefinitionShape  :  IfcProductDefinitionShape;
END_ENTITY;

Attribute definitions:

ShapeRepresentations  :  Contained list of shape representations. Each member defines a valid shape representation of a particular type within a particular representation context.
Name  :  The word or group of words by which the shape aspect is known. It is a tag to indicate the particular semantic of a component within the product definition shape, used to provide meaning. Example: use the tag "Glazing" to define which component of a window shape defines the glazing area.
Description  :  The word or group of words that characterize the shape aspect. It can be used to add additional meaning the the name of the aspect.
ProductDefinitional  :  An indication that the shape aspect is on the physical boundary of the product definition shape. If the value of this attribute is TRUE, it shall be asserted that the shape aspect being identified is on such a boundary. If the value is FALSE, it shall be asserted that the shape aspect being identified is not on such a boundary. If the value is UNKNOWN, it shall be asserted that it is not known whether or not the shape_aspect being identified is on such a boundary.
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EXAMPLE: Would be FALSE for a center line, identified as shape aspect, would be TRUE for a cantilever.
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PartOfProductDefinitionShape  :  Reference to the product definition shape of which this class is an aspect.

References (2):

Name Type Referred through Express-G
IfcProductDefinitionShape Entity
Attribute 'HasShapeAspects'
Diagram 2
IfcShapeRepresentation Entity
Attribute 'OfShapeAspect'
Diagram 2

Inheritance graph

ENTITY IfcShapeAspect;
ENTITY IfcShapeAspect;
ShapeRepresentations  :  LIST [1:?] OF IfcShapeRepresentation;
Name  :  OPTIONAL IfcLabel;
Description  :  OPTIONAL IfcText;
ProductDefinitional  :  LOGICAL;
PartOfProductDefinitionShape  :  IfcProductDefinitionShape;
END_ENTITY;