8

FFD (Free-Form Deformation) Modifiers 675
2.
Apply the FFD 2X2, FFD 3X3, or FFD 4X4
modifier, depending on the resolution of the
lattice you want.
An orange lattice gizmo surrounds the
geometry.
3. In the stack display, choose the Control Points
sub-object level, and then move the control
points of the lattice to deform t he underlying
geometry. (Turn on the Auto Key button if you
want to animate the deformation.)
The lattice volume defaults to the b ounding box
of the selected geometry. However, you can
position, rotate, and/or scale the lattice bo x so that
it modifies only a subset of vertices. Choose the
Lattice sub-object level, and then u s e any of the
transform tools to adjust the lattice volume relative
to the geometry.
Inter face
Modifier Stack
Control Points—At this sub-object level, you can
select and manipulate control points of the lattice,
one at a time or as a group (select multiple points
using standard techniques). Manipulating control
points affects the shape of t he underlying objec t.
You can use standard transformation methods
w ith the control points. If the Auto Key button is
turned on when modifying the control points, the
points become animated.
LatticeAt this sub-object level, you can position,
rotate, or scale the lattice box separately from the
geometry. If the Auto K ey button is turned on,
the lattice becomes animated. When you first
apply an FFD, its lattice defaults to a b ounding box
surrounding the geometry. Moving or scaling the
lattice s o that only a subset of vertices lies inside
thevolumemakesitpossibletoapplyalocalized
deformation.
Set Volume—At this sub-object level, the
deformation lattice control points turn green,
and you can select and manipulate control points
w ithout affecting the modified object. This lets you
fitthelatticemorepreciselytoirregular-shaped
objects, giving you finer control when deforming.
Set Volume essential ly lets you set the initia l state
ofthelattice.Ifyouuseitafteryouhaveanimated
acontrolpointorwhentheAutoKeybuttonis
turned on, then it works the same as at the Control
Points sub-object level, deforming t he object as
you manipulate points.
For more information on the stack display, see
Modifier Stack (page 3–802)
.