4.8.1.3 Axis Geometry
Elements following a path provide an 'Axis' representation indicating a line segment or any arbitrary open bounded curve. Examples of such elements include walls, beams, columns, pipes, ducts, and cables. For elements that have a material profile set association indicating cross-section, a 'Body' representation may be generated based on the axis curve and material profiles. Curve styles may indicate particular colors, line thicknesses, and dash patterns for 2D rendering.
The representation identifier of the axis representation is:
EXAMPLE A two-dimensional bounded curve is used as the wall axis in standard walls, a three-dimensional bounded curve is used as the reference axis in standard columns.
The following diagram shows the generic classes and relationships used when applying this concept.
In addition, concepts may have particular importance to common or standardised industry practices and scenarios. For these specific usage scenarios, the tables below shows a recommended list of general usage patterns that users may adopt.
G
<a href="IfcProduct.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcProduct.htm">IfcProduct</a>
IfcProduct GlobalId
[1:1]
OwnerHistory
[0:1]
Name
[0:1]
Description
[0:1]
HasAssignments
[0:?]
Nests
[0:1]
IsNestedBy
[0:?]
HasContext
[0:1]
IsDecomposedBy
[0:?]
Decomposes
[0:1]
HasAssociations
[0:?]
ObjectType
[0:1]
IsDeclaredBy
[0:1]
Declares
[0:?]
IsTypedBy
[0:1]
IsDefinedBy
[0:?]
ObjectPlacement
[0:1]
Representation
[0:1]
ReferencedBy
[0:?]
PositionedRelativeTo
[0:?]
ReferencedInStructures
[0:?]
<a href="IfcProductDefinitionShape.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcProductDefinitionShape.htm">IfcProductDefinitionShape</a>
IfcProductDefinitionShape Name
[0:1]
Description
[0:1]
Representations
[1:?]
ShapeOfProduct
[1:?]
HasShapeAspects
[0:?]
<a href="IfcProduct.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcProduct.htm">IfcProduct</a>:Representation1-><a href="IfcProductDefinitionShape.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcProductDefinitionShape.htm">IfcProductDefinitionShape</a>:IfcProductDefinitionShape0
<a href="IfcShapeRepresentation.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcShapeRepresentation.htm">IfcShapeRepresentation</a>
IfcShapeRepresentation ContextOfItems
[1:1]
Identifier
RepresentationIdentifier
[0:1]
Type
RepresentationType
[0:1]
Items
Items
[1:?]
RepresentationMap
[0:1]
LayerAssignments
[0:?]
OfProductRepresentation
[0:?]
OfShapeAspect
[0:1]
<a href="IfcProductDefinitionShape.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcProductDefinitionShape.htm">IfcProductDefinitionShape</a>:Representations1-><a href="IfcShapeRepresentation.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcShapeRepresentation.htm">IfcShapeRepresentation</a>:IfcShapeRepresentation0
<a href="IfcGeometricRepresentationContext.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcGeometricRepresentationContext.htm">IfcGeometricRepresentationContext</a>
IfcGeometricRepresentationContext ContextIdentifier
[0:1]
ContextType
[0:1]
RepresentationsInContext
[0:?]
CoordinateSpaceDimension
[1:1]
Precision
[0:1]
WorldCoordinateSystem
[1:1]
TrueNorth
[0:1]
HasSubContexts
[0:?]
HasCoordinateOperation
[0:1]
<a href="IfcShapeRepresentation.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcShapeRepresentation.htm">IfcShapeRepresentation</a>:ContextOfItems1-><a href="IfcGeometricRepresentationContext.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcGeometricRepresentationContext.htm">IfcGeometricRepresentationContext</a>:IfcGeometricRepresentationContext0
IfcLabel_0
IfcLabel
<a href="IfcShapeRepresentation.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcShapeRepresentation.htm">IfcShapeRepresentation</a>:RepresentationIdentifier1->IfcLabel_0:IfcLabel0
IfcLabel_1
IfcLabel
<a href="IfcShapeRepresentation.htm" tppabs="https://standards.buildingsmart.org/IFC/RELEASE/IFC4_3/lexical/IfcShapeRepresentation.htm">IfcShapeRepresentation</a>:RepresentationType1->IfcLabel_1:IfcLabel0
constraint_0
=Axis
IfcLabel_0->constraint_0
Figure 4.8.1.3.A Table 4.8.1.3.B