flat*, one_level, all_levels, all_parts
specifies the default for export of assemblies through iges. the optional values are:
- flat - converts the assembly to a single-level geometric model.
- one_level - exports only the assembly structure with pointers to component files.
- all_levels - exports the assembly structure to a single file and the components to iges files.
- all_parts - exports an assembly to iges as multiple files containing geometry information about the assembly components and assembly
features, if any.
