IFC Version
This parameter specifies the IFC version the writer will produce. Possible versions are IFC2x3 and IFC4. While IFC4 is the default value, many applications are not yet able to import this data, so it may be necessary to change the output version to IFC2x3.
GUID Seed Value
If this parameter is blank, the IFC writer will generate random GlobalId values for IFC objects. If the parameter value is non-empty, it will be used as a seed value for the GUID generator. This means that the GlobalId values generated by the writer will be reproducible from one workspace to the next. Objects with the same type, which arrive at the writer in the same order, will always have the same GlobalId, so long as the seed value doesn’t change.
This only applies to objects for which a new GlobalId value is required. If a feature arrives at the writer and the GlobalId attribute is already set to a valid GUID, that value will be used instead of using a newly generated value.
Representation Contexts
This parameter is the writer’s equivalent to the Representations To Read parameter on the IFC reader. When writing IFC object geometry, only the representations listed in this parameter will be written. In addition, for each representation identifier, only geometries whose type corresponds to one of the types listed in the Geometry Types column will be written.
The writer will look in two places to try and determine which representation a particular geometry should be part of:
- The geometry name can be set to the corresponding representation identifier.
- The ifc_representation_identifier trait may be set to the representation identifier.
If neither method produces a representation identifier which matches one of the values in the Identifier column of this parameter, the geometry will not be written.