2008

End Effector
In
history-dependent inverse kinematics (HD IK) on page 3346 , the end effector
is the pivot point of the selected child object at the end of a kinematic chain.
The kinematic chain is a single branch of a hierarchy used for animation with
inverse kinematics (IK) on page 7820 . The chain starts with the selected child
object and travels up through ancestors until it reaches the start of the chain.
When you move the end effector, the HD IK solver then uses IK calculations
to move and rotate all other objects in the kinematic chain to react to the
object you moved.
The end effector has two transforms: one that connects it to its parent, and
another that connects it to the End Effector Parent. By default, the End Effector
Parent is none (equivalent to World); you can assign this in the Motion panel.
NOTE You can move the end effector away from the child object, which causes
the IK chain to straighten out. When you move the end effector back toward the
child object, joints in the IK chain will bend again.
See also:
■
IK Goal on page 7812
Envelopes
In
Physique on page 4522 , the envelope is the primary tool for controlling skin
deformation. An envelope defines an area of influence about a single link in
the hierarchy. If the envelope is deformable on page 7752 , mesh vertices within
that envelope follow the movement of the Physique
deformation spline on
page 7753 . An envelope has a pair of inner and outer bounds; the envelope's
influence is strongest at the inner bound, and falls off toward the outer bound.
By default, each envelope has four cross sections. You can reshape the cross
sections, or add new ones, to change the envelope's geometry.
In the
Skin modifier on page 1600 , the envelope plays a similar role with respect
to bones. Each bone has its own envelope with two or more cross-sections
that allow you to shape the envelope to fit the surrounding mesh.
Typically, the envelopes of adjacent links or bones overlap each other. Vertices
that fall in the overlap area are weighted to produce smooth blending at joint
intersections.
Glossary | 7767