2009
Strength, Falloff, Radial Scale, and Overlap are grouped under Envelope
Parameters
on page 4722.
Envelopes have cross sections. You can add cross sections to refine the shape
of an envelope, and you can move or scale a cross section's control points to
change the cross section's shape. (Cross sections are also used to create
bulges
on page 4737.)
TIP You can also use tools on the Main toolbar to adjust envelopes. For example,
you can use Non-Uniform Scale on envelopes and cross sections, or use Select
And Move to move envelopes, cross sections, or control points on cross sections.
Workflow
The goal is to modify the envelopes so each vertex in the mesh is encompassed
by at least one link's envelope.
Usually the first adjustment is to assign a rigid envelope to the character's
head. A rigid envelope blends with other envelopes but retains the shape of
the mesh. The head should not deform with the deformation spline.
With Initial Skeletal Pose turned on, check that the envelopes enclose all areas
of the mesh. If you turn off Initial Skeletal Pose, the character adopts its
animated position at the current frame. Use an animation that stretches the
character around, such as a run or dance motion. Find a frame where the
envelopes need adjusting, and edit the envelope parameters. Changing the
envelopes with the character in an animated position will always reference
the Initial Skeletal Pose.
These are some frequently encountered problems with the default vertex
assignment:
■ Vertices that don’t follow the skeleton.
To correct this, increase the Radial Scale of an envelope's outer boundary.
■ Vertices at joints get pushed or dented in.
Too many envelopes might be affecting these vertices. Try reducing the
Radial Scale of the inner bound, and reduce the Overlap values of the links
on both sides of the joint.
■ Bending appears too linear or broken at the joint.
Increase the envelope’s outer Overlap value toward the link on the other
side of the joint.
Some further adjustments are described in the “Procedures” section that
follows.
4718 | Chapter 17 character studio