2009

runs through the joints in the hierarchy, and can be deformed using bulge
angles, tendons, and link parameters. Rigid envelopes determine vertex-link
assignment based upon the linear 3ds Max link and move in an immobile
relationship to the link. Vertices in a rigid envelope, however, are deformed
(blended) in the overlap area of other envelopes.
Typically you use deformable envelopes; however, game developers with
game-engine restrictions might want to use rigid envelopes exclusively. Both
rigid and deformable envelopes can be turned on for the same link. For
example, by scaling both envelopes, you could deform the shoulder with a
rigid envelope and the armpit with a deformable envelope.
The Number of Links That Can Affect a Vertex
Any number of overlapping envelopes (
N Links on page 8056) can influence
vertices. Normally, N Links are preferred. For special purposes such as games
requirements, you can limit the number of links (envelopes) that can affect
a vertex. The No Blending parameter is like the method used in version 1 of
the software; a vertex is assigned to only one link.
Physique Workflow
Before Physique is applied, align the biped to the mesh in
Figure mode on
page 4420. Use a pose with the arms outstretched so the hands are away from
the torso. Save a figure file, so it’s easy to return to this pose whenever you
need. Select the mesh and choose Physique in the Modify panel. Turn on
Attach to Node and select the root node in the hierarchy (biped Pelvis or root
node in a bones hierarchy, not the COM). In the Physique Initialization dialog
box, click Initialize to create default envelopes based on the links in the
hierarchy. The remainder of the work is adjusting envelopes and optionally
adding bulge angles and tendons.
Envelope size, overlap, and other parameters are adjusted with the character
in an animated position (with Figure mode turned off). By scrubbing the time
slider back and forth, you can spot problem areas and adjust the envelopes
affecting the problem areas. In Place mode is useful to keep the character
stationary during envelope adjustment.
The finishing touches are link parameters, bulge angles, and tendons. You use
link parameters to control skin sliding, the amount of twist, and crease
blending as a character moves. Bulge angles let you expand areas like the
biceps,and chest relative to the angle created by a link and its child in the
hierarchy. Tendons can span multiple links in the hierarchy to stretch and
pull a character skin.
4134 | Chapter 17 character studio