8

962 Chapter 9: Surface Modeling
When the Vertex sub-object level is ac tive, the
Geometry rollout on the Modify panel has the
options listed below.
Subdivision group
Bind—Lets you create a seamless, gapless
connection between two patch edges that have
unequal numbers of vertices. The two patches
mustbelongtothesameobject,andthevertex
need not be selected first. Click Bind, then drag
alinefromanedge-basedvertex(notacorner
vertex)totheedgeyouwanttobinditto. The
cursor turns into a white cross when over a legal
edge.
Binding patch edges
To exit Bind mode, click the Bind button again, or
right-click in the active v iewport.
Tip: When connecting two patches edge-to-edge,
first line up as m any pairs of vert ices as possible,
and use Weld to connect them. Then use Bind to
connect the remaining vertices. Bound vertices
cannot be manipulated directly, a lthough their
handles can.
Note: Bind is useful for connecting patch objects
with differen t patch resolutions, such as a head
andaneck,withouttheneedtocreateadditional
patches in the lower-resolution object.
Unbind—Disconnects a vertex connected to a
patch with Bind. Select the vertex, and then click
Unbind.
Topology group
Cr e a te—Creates a three or four-sided patch on
existing geometry or in free space. First turn on
Create and then click geometry or free space in the
view por ts to create a quad or a tri patch.
Patch vertices are selected by lef t-clicking existing
vertices. Left-clicking in free space creates a new
vertex at that location. If you digitize away from an
existi ng vertex then a new vertex is created and it
will be included in the sequence of vertices for the
new patch. The cursor changes to w hite cross hairs
when selecting an exist ing vertex.
To create a Tri Patch: Click three times in free space
or on existing vertices. Right-click, or left-click
oneoftheverticesinthecurrentsequenceto
complete the creation of a Tri Patch.
To c r e at e a Qu a d Pat c h : Click four times in free
space or on existing vertices. The Quad Patch will
be automatically created after the fourth click.
No operation will take place if you right-click or
selectavertexinthecurrentsequencewhenonly
one or two vertices are in the sequence.
Attach—Attaches an object to the cur rently
selected patch object. Click the object you want to
attach to the currently selected patch object.
For further details, see
Attach .
Reorient—When on, reorients the attached patch
so that each patch’s creation local coordinate
system is aligned with the creation lo cal coordinate
system of the selec ted patch.
Delete—Removes vertices from the framework.
Use this option with caution. Deleting a single
vertexalsodeletesanypatchesthatsharethis
control point. For example, if you delete the single