2011

Sliver Polygons
A sliver polygon is very long and thin; its perimeter is very large compared to
its area. When overlaying two topologies, AutoCAD Map 3D checks for sliver
polygons. When creating a new polygon topology, checking for sliver polygons
is optional.
NOTE This functionality is for drawing objects only. There is no equivalent for
geospatial feature data. However, when you perform
overlay analysis (page 1309)on
two geospatial feature layers, you can
check for sliver polygons (page 1565).
If a sliver polygon is detected, AutoCAD Map 3D highlights its centroid with
an X. To clear the Xs, use the REGEN command.
Though sliver polygons are not considered errors by AutoCAD Map 3D and
your topology can still be considered correct and complete, the sliver polygons
may be unintentional, for example, the result of digitizing errors. If you see
sliver polygons, you may want to double-check your data to make sure it is
correct and that the sliver polygons are expected.
For example, imagine you digitize two adjacent polygons, such as a parcel
and a flood plain, and there are slight overlaps between the two. Then, you
create topologies for each, overlay the topologies, and the resulting topology
contains sliver polygons. These may be correct or not, depending on your
data. If the boundaries between the adjacent polygons are meant to be the
same, then the sliver polygons are incorrect and you must correct your data.
If the boundaries are not meant to be the same, then sliver polygons are
correct.
Creating, Editing, and Managing Topologies | 841