The Standard Exchange Format (SEF) writer modules provide FME with the ability to write SEF data files. SEF files use a published ASCII format. The SEF data file structure is described in the FRAMME Loader Reference Guide.
This section assumes an operational knowledge of SEF.
Writer Overview
The SEF writer processes three kinds of features: workset info features, reference features, and regular features.
- Workset info features provide the SEF writer with the necessary information to create a workset when the output file is exported to FRAMME.
- Reference features are referenced multiple times in a workset.
- All other features are considered regular features.
It is also worth noting that the SEF writer does not handle donuts or cells.
SEF features can be associated with very complex feature geometries, and a single SEF feature can have multiple geometries of different geometric types. Here we refer to each geometric type in a SEF feature as a “component”. The structure of a SEF Component is explained in SEF Components.
In order to represent complex geometries in FME, it is necessary to use aggregates of geometry.
To handle the geometry inside each component, the SEF writer requires all geometry attributes associated with coordinates to be stored in the FME geometry of the SEF feature. The SEF writer expects all SEF features to be aggregates if they have more than one graphical component. As a rule of thumb, if there is more than one graphical component with a feature, the feature must be aggregated together.