Use AutoCAD Groups in FME

Using Group Features

The AutoCAD reader's Read Groups option will produce autocad_group features that can be used to aggregate your AutoCAD source features. The autocad_group features have no geometry, but do have a list of the entities that make up the group (autocad_entity{}). This list can be exploded into separate features in order to merge the group information onto the features in the group. 

The process shown above will aggregate the features into their groups. See GroupEntities.fmw, which is available in the Files section. 

Nested Groups

Nested groups are more complicated and will require multiple merges to recreate the grouped geometry.

To apply the next level of nesting, Groups without any matched entities (output from the UNREFERENCED port of the FeatureMerger) are merged onto the first set of group aggregates by matching the first-level group IDs to the second-level group list elements. The merged features are then aggregated again by the second-level group ID. An additional merge must be done for every expected level of nesting.

The example below can deal with three levels of nesting. See NestedGroupEntities.fmw, which is available in the Files section.