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#CV-2x3-106
agreed use of geometric representation context and subcontext
| number |
#CV-06-106 |
| based on |
IFC2x3 |
| affects |
extended coordination view |
| date |
24. Feb 2006 |
| initiator |
ISG meeting in Berlin |
| summary | agreed use of geometric representation context and subcontext |
Description
each IFC model shall have a maximum of 2 (and minimum of 1) instances of IfcGeometricRepresentationContext. The conventions to use the ContextType attributes are:
- IfcGeometricRepresentationContext.ContextType = 'Model' for all but annotations
- IfcGeometricRepresentationContext.ContextType = 'Plan' for annotations
Differentiation of Model representation context (to allow a better structured export) is supported by using IfcGeometricRepresentationSubContext. The conventions to use the ContextType attributes are:
- an IfcGeometricRepresentationContext.ContextType = 'Model' may have subcontexts.
- the IfcGeometricRepresentationSubContext.ContextIdentifier should be: 'BoundingBox', 'Box', 'Axis', 'FootPrint', 'Profile', 'Body'
- it refers to the IfcShapeRepresentation.RepresentationIdentifier of the included object geometry
[added 05-May-06] Differentiation of Plan representation context (to allow a better structured export) is supported by using IfcGeometricRepresentationSubContext. The conventions to use the ContextType attributes are:
- an IfcGeometricRepresentationContext.ContextType = 'Plan' may have subcontexts.
- the IfcGeometricRepresentationSubContext.ContextIdentifier should be: 'Plan', 'Annotation'
- required information (to allow the scaling of annotations, like line types, hatching, text) is the TargetScale attribute, it always has to be provided.
- the TargetView attribute is always set to .PLAN_VIEW.