E.6 Mapped geometric shape

The example demonstrates the use of various way to use mapped items to represent a simple geometric form of a building element proxy. All example files use the same representation map being a swept solid defining the shape (a block of 1m x 1m x 2m).

NOTE  See the example of "Basic geometric shape" for the definition of the swept solid. Any other shape representation, e.g. 'Brep', 'CSG', or 'SurfaceModel' could have been used to represent the representation map.

The basic structure provided with the sample IFC files include:

• the basic context of the data set provided by IfcProject and referenced entities:
  • IfcOwnerHistory for user, application and time stamp where the project data set had been created;
  • IfcGeometricRepresentationContext for the general context, including representation type, dimension, coordinate system, and precision;
  • IfcUnitAssignment for the default units used within the data set,
• the basic spatial structure of the project provided by a single IfcBuilding with referenced entities:
  • IfcLocalPlacement to create the local object coordinate system of the building being the parant coordinate system for all objects contained within the building;
  • IfcRelAggregates to link the IfcBuilding to the IfcProject as the uppermost item of the project spatial structure,
• the proxy element having a shape representation provided by a single IfcBuildingElementProxy with referenced entities:
  • IfcLocalPlacement to create the local object coordinate system of the proxy relative to the object coordinate system of the building;
  • IfcProductDefinitionShape to define the geometry within the local object coordinate system.

Depending on the model view definition some representation types may not be allowed in actual exchange scenarios.

  Link to this page