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Skin Wrap Modifier 819
control object, and point refers to a vertex on the
base object.
With Sk in Wrap, you can modify t he structure and
topology of the high-resolution object after setting
up the animation. The animation remains intact
because it is actually contained in the cont rol
object.
In most cases, when using Skin Wrap, the control
object is positioned near the modified base object,
and then bound to the latter using the modifier’s
Add function. By default, moving a vertex in
the control object affects nearby vertices in the
base object. Additional options allow faces in
the control object to affect the nearest points in
the base object instead (Blend To Base Object).
Conversely, points in the control object can affect
faces in the base object (Face Deformation).
Skin Wrap offers a great deal of control in that
youcansetadifferentstrengthvalueforeach
control vertex, as well as the shape of its volume
of influence. You can also convert the Skin Wrap
effect to a Skin modifier applied to the high-res
model, suitable for use with game engines. And
theabilitytoanimatewithmultiplecontrolobjects
lets a technical director assign animation of
different parts of a complex character mesh to
various artists.
Tip: If you use a control object to which
non-uniform scaling has been applied, its vertices
will have non-spherical volumes of influence,
which can lead to unexpected results. In such
a case, before adding the control object to the
modifier, apply Reset XForm (page 1–438) and
then collapse the stack.
See also
Skin Wrap Patch Modifier (page 1–824)
Procedure
To use Sk in Wrap (basic method):
1.
Create a high-resolution base object and one or
more low-resolution control objects, which will
deformthebaseobject.Ingeneral,eachcontrol
object should have an overall shape similar to
the part of the base object that it will deform,
and b e positioned near that part of the base
object.
2. Apply Skin Wrap to the high-resolution base
object. The modifier transfers animation or
modeling from the control object to the base
object.
3. On the Sk i n Wrap > Parameters rollout, use
Add to assign the control object(s).
4. Choose a deformation engine: Vertex or Face.
5. Set global parameters as desired. These
parameters affect all control vertices, and
include Deformation Engine, Falloff, Distance
Influence, and Face Limit.
6. To set local parameters, including strength and
influence distances, access the Control Vertices
sub-object level of the Skin Wrap . Select one
or more control ver tices, and then change the
settings as necessary.
7. Edit or animate the control object with
modifiers and/or sub-object transforms;
the high-resolution (base) object deforms
accordingly.
8. Repeat steps 5, 6, and 7 as necessary.
Occasionally you mig ht need to reset the
modifier as well, by clicking the Reset
button. Before doing so, always return to a
non-deformed point (or “skin pose”) in the
animation; typically, frame 0.