8

1016 Chapter 9: Sur face Modeling
You can also connect borders between objects with
the
Connect compound object (p age 1–323) .
Polygon—Tur ns on Polygon sub-object level,
which lets you select polygons beneath the cursor.
Region selection selects multiple polygons within
the region.
Element—Turns on Element sub-object level,
which lets you select all contiguous polygons in an
object. Region select ion lets you select multiple
elements.
By Vertex—When on, you can select sub-objects
only by selecting a vertex that they use. When you
click a vertex, all sub-objec ts that use the selected
vertex are selected.
Igno re Backfacing—When on, selection of
sub-objects affects only those facing you. When
off (the default), you can select any sub-object(s)
under the mouse cursor, regardless of their
visibility or facing . If there are more than one
sub-object under the cursor, repeated clicking
cyclesthroughthem. Likewise,withIgnore
Backfacing off, region selection includes all
sub-objects, regardless of the direction they face.
Note: ThestateoftheBackfaceCullsettinginthe
Display p anel does not affect sub-object selection.
Thus, if Ignore Backfacing is off, you can still select
sub-objects, even if you can’t see them.
By Angle—When on and you select a polygon,
the software also selects neighboring polygons
basedontheanglesettingtotherightofthecheck
box. This value determines the maximum angle
between neighboring polygons to select. Available
only at the Polygon sub-object level.
For example, if you click a side of a box and the
angle value is less than 90.0, only that side is
selected, because all sides are at 90-degree angles
to each other. But if the angle value is 90.0 or
greater, a l l sides of the box are selected. This
function speeds up selection of contiguous areas
made up of polygons that are at simi lar angles to
one another. You can select coplanar polygons
with a single click at any angle value.
Shrink—Reduces the sub-object selection area
by deselecting the outermost sub-objects. If
the selection size can no longer be reduced, the
remaining sub-objects are deselected.
Grow—Expands the selection area outward in all
available directions.
Forthisfunction,aborderisconsideredtobean
edge select ion.
With Shrink and Grow, you can add or remove neighboring
elements from the edges of your current s election. This
works at any sub-object level.
Ring—Expandsanedgeselectionbyselectingall
edges parallel to the selected edges. R ing applies
only to edge and border selections.