Graphics Programs Reference
In-Depth Information
Binding the Hand: Smooth
Now, try skinning the hand with Smooth Bind.
Load your prebound hand or
poly_hand_skeleton_v02.ma
from the Poly_Hand_Anim
project on the CD. Now, follow these steps to smooth-bind the hand:
1. Select the root at the wrist and the top node of the hand (if you're using the hand
from the CD, make sure you have the nails as well). Choose Skin
➔
Bind Skin
➔
Smooth Bind.
2. Try rotating some of the knuckle joints to see how the fingers respond. Go back to
the bind pose when you're done.
3. Rotate the middle knuckle of the index finger down. Notice how the knuckle gets
thinner the more you bend the finger there. Go to the top knuckle of the index fin-
ger, and rotate that joint. Notice that part of the hand moves with the finger. This
is again exaggerated because the hand is polygonal, so its deformations seem more
severe than a NURBS model of the same hand. Figure 9.41 shows the result of bend-
ing at the index finger.
Figure 9.41
Bending at the
index finger causes
some unwanted
deformation.
Editing a Smooth Bind
You usually edit a smooth bind by
painting skin weights
. Because points on the model are
influenced by multiple joints in a smooth bind, you need to adjust just how much influ-
ence is exerted by these joints on the same points:
1. Make sure you're in Shaded mode (press 5). Select the hand, and then choose Skin
➔
Edit Smooth Skin
➔
Paint Skin Weights Tool
r
.
You paint skin weights on the affected geometry and not on the joints themselves, so you
need to select the model and not the skeleton before invoking this tool.
