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460 Chapter 12: Animation
Inter face
Spline O ptio ns group
IK Name—SetsthenameoftheIKchainobject.
Thisobjectappearsasasetofbluecrosshairsat
theendofthechainafterOKisclicked.
Auto Create Spl ine—Automatically creates the
spline used for the Spline IK solver based on the
parameters on this dialog. When t his option is not
turned on, no spline is created and a spline must
be manually created and assigned to the spline IK
solver in order to use the solver. See
Animating
w ith the Spline IK S olver (page 2–455)
for this
procedure. Default=on.
Bezier—Creates a Bezier spline, similar to a spline
createwiththeCreate>Shapes>Linetool.
NURB S Poi nt—Creates a NURBS Point Curve,
where all knots (cont rol nodes) lie on the curve.
NURB S CV —Creates a NURB S CV Cur ve, where
knots (control nodes) do not necessarily lie on
the curve.
Number of S pline K nots—Spline knots are similar
to vertices on a spline, or control points and CVs
on a NURBS curve. The spline or curve is altered
by moving and animating the knots. The number
of knots sets the degree of refinement on the curve
as well as the number of points that can be selected
and moved to change the shape of the curve.
The Number of Spline Knots defaults to the
number of bones in the Spline IK chain. Since
thepurposeofaSplineIKsolveristoreducethe
number of objects that require animation, you
would ordinarily set the Number of Spline Knots to
a lower number , such as half the number of bones.
Helper Options group
When creat ing the spline for Spline IK, helper
objects can be placed at each knot, mak ing it easier
to move and animate the knots. More than one
t ype of display c an be enabled.
Center M ar ker —Displays a small X marker at each
knot.
Axis Tripod—Displays a trip od axis at each knot.
The axis remains visible when the helper is no
longer selected.
Cr o s s—Displays a cross at each knot.
Box—Displays a small box at each knot.
Size—Setsthesizeforhelpers.
Constant Screen S iz e—Keepsthesizesofhelpers
constant regardless of how much viewports are
zoom in or out.
Draw On Top—Displays the helpers on top of all
other objects in the scene.
See also
Animating with the Spline IK Solver (page 2–455)