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