8

FFD (Box/Cylinder) Modifiers 677
Outs id e Po int s—
Only control points outside the
object are affected by Conform to Shape.
Offset—The distance by which control points
affected by Conform to Shape are offset from the
object surface.
About—Displays a dialog with copyright and
licensing information.
FFD (B ox /Cylinder) Modifiers
Modify panel > Make a selection. > Modifier List >
Object-Space Modifiers > FFD(box) or FFD(cyl)
Make a selection. > Modifier s menu > Free Form
Deformers > FFD Box or FFD Cylinder
FFD stands for Free-Form Deformation. Its effect
is used in computer animation for thing s like
dancing cars and gas tanks. You can use it as well
for modeling rounded shapes such as chairs and
sculptures.
The FFD modifier surrounds the selected
geometry with a lattice box. By adjusting the
control points of the lattice, you deform the
enclosed geometry. With the Auto Key button
turned on, you can animate the lattice points, and
thus the deformation of the geometry.
FFD deformation creates a bulge in the snak e.
With the FFD(box) and FFD(cyl) modifiers you
can c reate b ox-shaped and c y linder-shaped lattice
free-form deformation objects. Both are available
as objec t modifiers and as space warps.
The source lattice of an FFD modifier is fitted to
the geometry it’s assig ned in the stack. This can b e
a whole object, or a sub-object selection of faces
or vertices.
Interf ace
Modifier Stack
Co ntrol 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 the underlying object.
You c an use standard transformation methods
w ith the control points. If the Auto Key button is
turned on when modifying the control points, the
points b e come animated.
Lattice—At 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 a n FFD, its lattice defaults to a bounding box
surrounding the geometry. Moving or scaling the
lattice so that only a subset of vertices lie 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