2009

uniformly transformed. This makes it simple for game engines to move the
character's skin.
The vertices move equally with the controlling link, so the skin appears rigid.
For instance, in the case of a flexing arm, the skin between the wrist and elbow
tightly follows the movement of the forearm, with no change in the spacing
between vertices. The skin between the elbow and shoulder tightly follows
the upper arm. Vertices around the elbow influenced by both links, smoothly
blend to an average position between the two changed links.
Rigid and deformable envelopes can be mixed on a given character. You might,
for instance, use deformable envelopes for most of the character, but choose
rigid for the head and for a suit of armor around the torso.
NOTE In Link sub-object, you can turn on twisting for rigid envelopes. As the wrist
twists the vertices on the forearm will twist also.
See also:
■ Envelope Sub-Object on page 4717
Working with Both Deformable and Rigid
Envelopes
You can assign both Deformable and Rigid to a given link. For example, you
might assign both to the shins, and size the envelopes differently to gain the
benefits of both.
First, size the deformable envelope to affect the whole lower leg area and
smoothly transition into the thigh and ankle areas. Next, you define a smaller
rigid envelope to encompass the stiff unbendable section of the shin. Increase
the weight of the rigid envelope to balance its effect against that of the
deformable envelope.
Some users might use both envelopes as a way to have a bone affect two
completely separate regions of a mesh. The envelopes are scaled so that the
deformable envelope influences certain vertices on one side of the link and
the rigid envelope affects the other side.
See also:
■
Envelope Sub-Object on page 4717
Using Physique | 4643