CAD geometries can be complex to visualize because most are drawn with 'zero width' lines. The polygon-inside-of-polygon is often the hardest mistake to catch and it’s almost impossible to visually determine the polarity for each. A mask operator can sometimes take hours attempting to repair or redraw the data so that re-entrant polygons are created with voids or has to break up the polygons into slices. In any case, the production of the mask is delayed and it is possible to introduce additional mistakes while performing the editing.
Polygon De-Embedding automatically solves the polygon-inside-of-polygon problem (see below).
Wouldn’t it be nice if there was complete product developed just for these situations? Numerical Innovations has developed several products that include Polygon De-Embedding feature: ACE 3000, and FAB 3000. To use Polygon De-Embedding during DXF import, select layer option "De-Embed" for each layers you wish to perform De-Embedding. To may also select objects, and go to menu: Edit | De-Embed...
By Simon Garrison