4.1.9.8 Project Representation Context
A project representation context indicates the coordinate system orientation, direction of true north, precision, and other values that apply to all geometry within a project or project library. A main geometric representation context is created for 3D model, and 2D representations, both can be further refined using geometric representation sub contexts.
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 table below shows a recommended list of general usage patterns that users may adopt.
G
IfcContext
IfcContext
1. GlobalId
[1:1]
2. OwnerHistory
[0:1]
3. Name
[0:1]
4. Description
[0:1]
HasAssignments
[0:?]
Nests
[0:1]
IsNestedBy
[0:?]
HasContext
[0:1]
IsDecomposedBy
[0:?]
Decomposes
[0:1]
HasAssociations
[0:?]
5. ObjectType
[0:1]
6. LongName
[0:1]
7. Phase
[0:1]
8. RepresentationContexts
[1:?]
9. UnitsInContext
[0:1]
IsDefinedBy
[0:?]
Declares
[0:?]
IfcGeometricRepresentationContext
IfcGeometricRepresentationContext
ContextIdentifier
1. ContextIdentifier
[0:1]
ContextType
2. ContextType
[0:1]
RepresentationsInContext
[0:?]
3. CoordinateSpaceDimension
[1:1]
4. Precision
[0:1]
5. WorldCoordinateSystem
[1:1]
6. TrueNorth
[0:1]
HasSubContexts
[0:?]
HasCoordinateOperation
[0:1]
IfcContext :RepresentationContexts1->IfcGeometricRepresentationContext :IfcGeometricRepresentationContext0
IfcLabel_5
IfcLabel
IfcContext :Phase1->IfcLabel_5:IfcLabel0
IfcLabel_6
IfcLabel
IfcContext :ObjectType1->IfcLabel_6:IfcLabel0
IfcLabel_7
IfcLabel
IfcContext :LongName1->IfcLabel_7:IfcLabel0
IfcLabel_0
IfcLabel
IfcGeometricRepresentationContext :ContextIdentifier1->IfcLabel_0:IfcLabel0
IfcLabel_1
IfcLabel
IfcGeometricRepresentationContext :ContextType1->IfcLabel_1:IfcLabel0
IfcDimensionCount
IfcDimensionCount
IfcGeometricRepresentationContext :CoordinateSpaceDimension1->IfcDimensionCount :IfcDimensionCount0
IfcAxis2Placement3D
IfcAxis2Placement3D
LayerAssignment
[0:1]
StyledByItem
[0:1]
1. Location
[1:1]
2. Axis
[0:1]
3. RefDirection
[0:1]
IfcGeometricRepresentationContext :WorldCoordinateSystem1->IfcAxis2Placement3D :IfcAxis2Placement3D0
IfcDirection_2
IfcDirection
LayerAssignment
[0:1]
StyledByItem
[0:1]
1. DirectionRatios
[2:3]
IfcGeometricRepresentationContext :TrueNorth1->IfcDirection_2:IfcDirection0
IfcGeometricRepresentationSubContext
IfcGeometricRepresentationSubContext
SubContextIdentifier
1. ContextIdentifier
[0:1]
SubContextType
2. ContextType
[0:1]
RepresentationsInContext
[0:?]
3. CoordinateSpaceDimension
[1:1]
4. Precision
[0:1]
5. WorldCoordinateSystem
[1:1]
6. TrueNorth
[0:1]
HasSubContexts
[0:?]
HasCoordinateOperation
[0:1]
7. ParentContext
[1:1]
8. TargetScale
[0:1]
9. TargetView
[1:1]
10. UserDefinedTargetView
[0:1]
IfcGeometricRepresentationContext :HasSubContexts1->IfcGeometricRepresentationSubContext :ParentContext0
IfcCartesianPoint
IfcCartesianPoint
LayerAssignment
[0:1]
StyledByItem
[0:1]
1. Coordinates
[1:3]
IfcAxis2Placement3D :Location1->IfcCartesianPoint :IfcCartesianPoint0
IfcDirection_0
IfcDirection
LayerAssignment
[0:1]
StyledByItem
[0:1]
1. DirectionRatios
[2:3]
IfcAxis2Placement3D :Axis1->IfcDirection_0:IfcDirection0
IfcDirection_1
IfcDirection
LayerAssignment
[0:1]
StyledByItem
[0:1]
1. DirectionRatios
[2:3]
IfcAxis2Placement3D :RefDirection1->IfcDirection_1:IfcDirection0
IfcLabel_2
IfcLabel
IfcGeometricRepresentationSubContext :ContextIdentifier1->IfcLabel_2:IfcLabel0
IfcLabel_3
IfcLabel
IfcGeometricRepresentationSubContext :ContextType1->IfcLabel_3:IfcLabel0
IfcPositiveRatioMeasure
IfcPositiveRatioMeasure
IfcGeometricRepresentationSubContext :TargetScale1->IfcPositiveRatioMeasure :IfcPositiveRatioMeasure0
IfcGeometricProjectionEnum
IfcGeometricProjectionEnum
IfcGeometricRepresentationSubContext :TargetView1->IfcGeometricProjectionEnum :IfcGeometricProjectionEnum0
IfcLabel_4
IfcLabel
IfcGeometricRepresentationSubContext :UserDefinedTargetView1->IfcLabel_4:IfcLabel0
Figure 4.1.9.8.A
General UsageTable 4.1.9.8.B