8

1060 Chapter 9: Sur face Modeling
For example, if you extr ude a polygon, and want to
apply the same extrusion to several others, select
the others, and then click Repeat Last.
You c an apply a spline ex trusion of a single polyg on (left)
repeatedly to other single polygons (1) or to multiple
polygon select ions, contigu ous (2) or not (3).
Note: Repeat Last does not repeat all operations.
For instance, it does not repeat transforms. To
determine which command will be repeated when
you click the button, check the button’s tooltip. If
no tooltip appears, nothing will happen when it is
clicked.
Constra ints—Lets you use existing geometry to
constrain sub-object transformation. Use the
drop-down list to choose the constraint type:
• None: No constraints.
• Edge: Constrain transformed sub-objects to
edge boundaries.
• Face: Constrain transfo rmed sub-objects to
face surfaces.
Note: The Constraints sett ing persists at all
sub-object levels.
Preserve UVs —When on, you can edit polygons
and elements without affecting the objec t’s UV
mapping. You can choose any of an object’s
mapping channels to preserve or not; see Preserve
UVs Sett i ngs, following . Default=off.
Without Preserve UVs, there is always a direct
correspondence b etween an object’s geometry and
its UV mapping. If you map an object, and then
move polygons, the texture moves along w ith the
sub-objects, whether you want it to or not. If you
turn on Preserve UVs, you can perform minor
editing tasks without changing the mapping.
Tip: For b est results with Preserve UVs, use it
for limited polygon editing. For example, you’ll
usually have no trouble moving a polygon within
edge or face constraints. Also, it’s better to
perform one big move than several smaller moves,
as multiple small m oves can begin to distort
the mapping. If, however, you need to perform
extensive geometr y editing while preserv ing
mapping, use the
Channel Info utility (page
2–1549)
instead.
Preserve UVs Sett ings—Opens the Preserve Map
Channels dialog (page 1–1076)
,whichletsyou
specify which vertex color channels and/or texture
channels (map channels) to preserve. By default,
all ver tex color channels are off (not preserved),
and all texture channels are on (preserved).
Cr e a te—Lets you create polygons from isolated
vertices and border vertices. All vertices in the
object are highlig hted. C lick three or more existing
vertices in succession to define the shape of the
new polygon. (The cursor changes to a cross when
it is over a vertex that can legally be part of the
polygon.) To finish polygon creation, double-click
the last vertex. You can also finish creating the
polygon by clicking any vertex of the new polygon
a second t ime. You can a lso create new polygons
at the Element sub-object level, and at the Object
level.
Yo u c a n a d d v e r t i c e s i n t h i s m o d e b y
SHIFT+clicking in an empty space; these vertices
are incorporated into the polygon you’re creating.
You can star t creating polygons in any viewport,
but all subsequent clicks must take place in the
same v iewport.
Tip: For best results, click vert ices in
counterclockwise (preferred) or clockwise
order . If you use clockwise order , the new polygon
will be facing away from you, and you won’t be
abletoseeitunlessyou’veturnedonForce2-Sided
or are using a two-sided material.