DonutBuilder

From Fmepedia

DonutBuilder is a Workbench Transformer.

Cuts holes in polygonal features by making polygons completely enclosed in other polygons into holes of the containing polygon.

When a donut polygon is created by adding in hole features, any holes which share a common edge are dissolved together to make a single hole.

The <drop holes> flag indicates whether or not features used to cut holes in containing features should themselves be dropped or output.

The <hole flag> attribute will be added to each output feature and will contain "yes" if that feature was used to cut a hole into some containing feature, and "no" if that feature was not used as a hole.

Area features may be considered in groups based on the value of one or more attributes. Only features in the same group are then considered for hole nesting.

The DonutBuilder assumes that the input area features are topologically clean and that no polygons within a group overlap. In order to ensure this, an Intersector can be used prior to baking the donuts

The DonutBuilder is currently under development to be compatible with the new Rich Geometry Model.