4.1.9.4 Project Global Positioning
Adding a geospatial coordinate reference to the geometric representation context using a recognized coordinate reference system (CRS). This allows to position the project coordinate system on Earth (normally using eastings, northings, elevation above horizontal and vertical datums, and orientation).
HISTORY New concept template enabled by schema enhancements in IFC4.
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
IfcProject
IfcProject
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
1. ContextIdentifier
[0:1]
2. ContextType
[0:1]
RepresentationsInContext
[0:?]
3. CoordinateSpaceDimension
[1:1]
4. Precision
[0:1]
5. WorldCoordinateSystem
[1:1]
6. TrueNorth
[0:1]
HasSubContexts
[0:?]
HasGlobalPosition
HasCoordinateOperation
[0:1]
IfcProject :RepresentationContexts1->IfcGeometricRepresentationContext :IfcGeometricRepresentationContext0
IfcLabel_1
IfcLabel
IfcProject :ObjectType1->IfcLabel_1:IfcLabel0
IfcLabel_2
IfcLabel
IfcProject :LongName1->IfcLabel_2:IfcLabel0
IfcMapConversion
IfcMapConversion
1. SourceCRS
[1:1]
2. TargetCRS
[1:1]
Eastings
3. Eastings
[1:1]
Northings
4. Northings
[1:1]
OrthogonalHeight
5. OrthogonalHeight
[1:1]
XAxisAbscissa
6. XAxisAbscissa
[0:1]
XAxisOrdinate
7. XAxisOrdinate
[0:1]
8. Scale
[0:1]
IfcGeometricRepresentationContext :HasCoordinateOperation1->IfcMapConversion :SourceCRS0
IfcLengthMeasure_0
IfcLengthMeasure
IfcMapConversion :Eastings1->IfcLengthMeasure_0:IfcLengthMeasure0
IfcLengthMeasure_1
IfcLengthMeasure
IfcMapConversion :Northings1->IfcLengthMeasure_1:IfcLengthMeasure0
IfcLengthMeasure_2
IfcLengthMeasure
IfcMapConversion :OrthogonalHeight1->IfcLengthMeasure_2:IfcLengthMeasure0
IfcReal_0
IfcReal
IfcMapConversion :XAxisAbscissa1->IfcReal_0:IfcReal0
IfcReal_1
IfcReal
IfcMapConversion :XAxisOrdinate1->IfcReal_1:IfcReal0
IfcReal_2
IfcReal
IfcMapConversion :Scale1->IfcReal_2:IfcReal0
IfcProjectedCRS
IfcProjectedCRS
CRSName
1. Name
[0:1]
2. Description
[0:1]
3. GeodeticDatum
[0:1]
HasCoordinateOperation
[0:1]
WellKnownText
[0:1]
4. VerticalDatum
[0:1]
5. MapProjection
[0:1]
6. MapZone
[0:1]
7. MapUnit
[0:1]
IfcMapConversion :TargetCRS1->IfcProjectedCRS :IfcProjectedCRS0
IfcLabel_0
IfcLabel
IfcProjectedCRS :Name1->IfcLabel_0:IfcLabel0
IfcText
IfcText
IfcProjectedCRS :Description1->IfcText :IfcText0
IfcIdentifier_0
IfcIdentifier
IfcProjectedCRS :GeodeticDatum1->IfcIdentifier_0:IfcIdentifier0
IfcIdentifier_1
IfcIdentifier
IfcProjectedCRS :VerticalDatum1->IfcIdentifier_1:IfcIdentifier0
IfcIdentifier_2
IfcIdentifier
IfcProjectedCRS :MapProjection1->IfcIdentifier_2:IfcIdentifier0
IfcIdentifier_3
IfcIdentifier
IfcProjectedCRS :MapZone1->IfcIdentifier_3:IfcIdentifier0
Figure 4.1.9.4.A
General UsageTable 4.1.9.4.B