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1086 Chapter 14: character studio
B lendi ng B et ween Li nks
Blending between envelopes controls deformation .
Blending controls specify the influence of
overlapping envelopes on vertices contained
within the overlap area. By the actual shape of
adjacent envelopes, you can control the degree of
influence each has on blending at the overlap area.
You can further control the number of en velopes
that participate in the blending effect, or whether
no blending takes place at all. Where you specify
no blending, a vertex in an overlap area is
influenced by a single lin k only.
Inner a nd Outer B ounds
Inner and outer bounds
Where a vertex falls within the inner and outer
bounds determines the percent of influence of the
attached link(s). Vertices that fal l within the inner
boundhaveaweightof1.Verticesthatfallbetween
theinnerandouterboundhaveaweightedvalue
that fal ls off to 0 at the outer bound.
Vertices are color—coded in the viewports
according to their weight; the color is based on
parameters you specify in the Blending Envelope
Display Options Dialog (page 2–1125).
See also
Envelope Sub-Object (page 2–1130)
Adjusting Default Envelope Shape
When you want to address vertex-linking
anomalies, the first step is to resize or reposition
the envelope about the problem link. Most often,
the problem is an envelope that istoo small to
surround, and thereby influence, certain vertices.
Thiscanhappenbecauseyourbipedcharacter
misaligns slightly with t he mesh, or the link
lengths used to create envelopes with unbounded
bonessystemslinkswereinsufficienttosurround
all vertices attached to the link.
Another potential source of problems is
overlappinginnerbounds.Thiscansometimes
create too strong a deformation at the joint.
Yo u’ l l n o t e p r o b l e m s w i t h v e r t i c e s a s y o u p r e v i e w
motion. It sometimes looks lik e vertices got left
behindwhenthelinktheyweresupposedtobe
attached to moves in 3D space. In fact, that’s just
what is happening: they weren’t assigned to any
link at all, and remain where they were at the initial
skeletal pose: the pose of the mesh and its skeleton
atthetimePhysiquewasappliedandinitialized.
The other case would be vertices being moved too
much, resulting in a dent in the mesh. You’d fix
this by decreasing the overlap of the envelopes
affecting a joint.