9

FFD (Box/Cylinder) Modifiers 685
Sour ce Volume—
Displays the control points and
lattice in their unmodified state.
When you’re in the Lattice selection level, this
helps to position the source volume.
Tip: Toseewhichpointslieinthesourcevolume
(andthereforewillbedeformed),temporarily
deactivate the modifier by clicking to turn off the
light bulb icon in the modifier stack d isplay.
Deform group
Only in Volume—Deforms vertices that lie inside
thesourcevolume.Default=on.
All Ver tices—Deforms a ll vertices, regard less of
whether they lie inside or outside the source
volume.
The deformation outside the volume is a
continuous extr apolation of the deform ation
insidethevolume. Thedeformationcanbe
extreme for points far away from the source lattice.
Control Points group
Reset—Returns all cont rol points to their orig inal
positions.
Animate All—Assigns Point3 controllers to all
control points so that they’re immediately visible
in Track View.
By default the control points of an FFD lattice
don’t appear in Track View because they don’t have
controllers ass igned to them. But when a control
point is animated, a controller is assigned to it and
becomes visible in Track View. With Animate All,
you can add and delete keys and perform other
key operations.
Confor m to Sha pe—Moves each FFD control point
to the intersection of the modified object with a
straight line extending b etween t he object’s center
to the control point’s original location, plus an
offset distance specified by the Offset spinner.
Note: Conform to Shape works best with regular
shapes, such as primitives. It’s less effective if
the object has degenerate (long, narrow) faces or
sharp corners. All the controls are unavailable with
shapes, because there are no faces to intersect with.
Inside Points—Only control points inside the object
are affected by Conform to Shape.
Outs id e Poi nts —Only control points outside the
object are affected by Conform to Shape.
Offset—Thedistancebywhichcontrolpoints
affected by Conform to Shape are offset from the
object surface.
About—Displays a dialog with copy right and
licensing information.
FFD (Box /Cy lin der) M odifi ers
Modify panel > Make a selection. > Modifier List >
Object-Space Modifiers > FFD(box) or FFD(cyl)
Make a selection. > M o difiers menu > Free Form
Deformers > FFD Box or FFD Cylinder
FFD stands for Free-Form Deformation. Its effect
is used in computer animat ion for things like
dancing cars and gas tanks. You can use it as well
for modeling rounded shapes such as chairs and
sculptures.
The FFD mo difier 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.