2011

■ Layer Name: Specify the name of the Display Manager layer that will
contain the result of the Overlay operation.
■ Sliver Tolerance: Specify which slivers become separate features and
which are joined with a neighboring polygon. Set the units for the
tolerance setting, then set the maximum and minimum values.
To see recommended values, click Suggest. The default suggested
values for sliver tolerances are 1/10 of the smallest input area for the
Maximum and 1/100 of the smallest input area for the Minimum.
When the Overlay operation splits features to produce the output
layer, it eliminates polygons that are smaller than the specified
tolerance settings. Some such polygons were present in the sources,
and some are produced by the Overlay operation itself. The
elimination of slivers affects the output layers only.
Polygons whose areas are larger than the Maximum value become
separate features in the output layer.
Polygons whose areas are smaller than the Minimum (and have at
least one neighboring polygon) are considered slivers, and are merged
with the neighboring polygon that has the longest shared edge.
The Overlay operation checks polygons that fall between the two
values to see how wide they are. If they are very narrow, they are
merged with a neighboring polygon.
NOTE If the resulting polygons are not as desired, try adjusting the
tolerance values and repeating the Overlay operation.
To ignore slivers altogether, click Don’t Remove Slivers.
■ Ordinate Tolerance: Specify how far apart two nodes or vertices of a
line or polygon must be to be treated as separate points in the output
layer. Set the units for the tolerance setting, then set the Length.
Any two points that are closer together than the Length value are
treated as a single point in the output layer.
■ Output Properties: Specify which properties from the Source and (if
applicable) Overlay are included in the resulting layer.
“All” adds all properties to the resulting layer. “Identifiers” adds only
the primary identifiers (primary keys or unique fields, such as
Feature_ID). “Non-Identifiers” adds only the non-key attributes (such
as Land_Value or Speed_Limit, for example). If you add only
non-identifiers, the overlay operation generates primary identifiers
for the features in the resulting layer.
Overlaying Two Feature Sources | 1317