Design Verification (DV) layers are geometries grouped into logical collections, then used as input/output for DV commands. The geometry of a DV layer may be saved as results that can be later viewed in the Layout Editor. The contents of a DV layer may be imported on the Layout Editor or created by a DV command.
A DV layer contains the following types of graphical information:
- Error Clusters – Grouped segments that represent the results of a DV check. Usually a cluster contains two segments, but under certain conditions there may be more or less. These segments contain no polygon information. Segments may be a single point.
- Polygons – Closed geometric figures that may contain holes. These polygons may be grouped.
- Edges – Segments that contain some relationship information from previously belonging to a polygon. An edge, for instance, contains the directions "inside" and "outside" of the polygon and is able to determine if another edge was part of the same polygon. This information allows the edges to be used as input to other DV commands.
DV commands return DV layers with error clusters or polygons. Import commands, ObjectCreation commands and ConnectivityChecking commands return DV layers containing polygons. There are DV (Geometry Checking) commands that return each type of DV layer.