8

696 Chapter 8: Modifiers
beneath the cursor; region selection selects
multiple edges within the region.
Poly gon—Turns on Polygon sub-object mode,
whichletsyouselectasinglefaceorpolygon.A
polygon is the area you see within the visible wire
edges. Region selection selects multiple polygons
within the region.
Element—Tur ns on E leme nt sub -o bjec t
mode, which lets you select all contiguous
polygons beneath the cursor in the current level
of detail.
Ignore B a ck fa cing—When on, you can select only
thosesub-objectswhosenormalsarevisiblein
the viewport. When off (the default), selection
includes all sub-objects, regardless of the direction
of their normals. Default=off.
Only Curr ent Level—Displays only polygons at the
current level of detail, with highlig hts, but without
smoothing. Us e this option to speed up the display
when working with complex objects. Default=off.
Subdivision Stack—Shows the current level of the
subdivision hierarchy. Automatically increments
when you subdivide a sub-object selection. To edit
at a different level of detail, select the level in the
stack. The current level is outlined in red.
• V isibility is controlled by the box icon to the
right of the level label. Turning on the visibility
at one level activates the visibility from that
level down to the base level. Visibility above
thatlevelwillbeturnedoff.
Subdivide—Performs subdivision and smoothing
on the current selection, and adds a level to the
Subdivision Stack. When the subdivision results
in a control grid and other subdivisions have been
performed at the same level of detail, the control
grids may become interconnected.
Vertex Interpolation group—
Determines how selected ver t ices are treated
during subdivision. Available only in Vertex
sub-object mode.
For best results, u se when moving control gr id
vertices at a level of deta il lower than the highest in
which the vertex resides.
Standard/Conic/Cusp/Corner—Determines how
closely mesh vertices follow the movement of
control g rid vert ices. Standard provides the
least amount of relative movement, while Cusp
and Corner provide the most. Corner also
keeps edges adjacent to subdivided vertices
from being rounded off during subdivision.
Default=Standard.
Note: Corner is available only when the selected
vertex or vertices aren’t surrounded by polygons,
such as the vertices on the edge of a plane object.
Edge Cr ease grou p—
Determines the extent to which selected edges are
treated as creases during subdiv ision. Available
only in Edge sub-object mode.
For best results, use with control grid edges at
a level of detail lower than the highest in which