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Spline IK Solver Rollouts 461
Spline IK Solver R ollouts
Select a Spline IK Solver control (the blue cross at the end
of the chain) > Motion panel > Parameters button
When a Spline IK chain is selected, the options
ontheMotionpanelcanbeusedtochangethe
starting and ending bones, and twist angles for the
entire linked struc ture.
To c r e ate a Spli n e I K S o l ve r, s e e
Animating with
the Spline IK Solver (page 2–455)
.
Inter face
Spline IK Solver rollout
The options on this rollout allow you to pick a new
spline for the spline IK chain, or pick new start and
end joints for the chain.
Spline IK Solver group
Spline IK Solver—Displaysthenameofthesolver.
The only available solver is Spline IK Solver.
Enabled—Turns control of the solver on and off.
Bone Joints group
Pick Sta r t Joint—Picks the start joint for the Spline
IK Solver and d isplays the object name.
Pick End Joint—Picks the end joint for the Spline
IK Solver and d isplays the object name.
IK Solver Properties rollout
The options on this rollout se t the start and end
twist angles for the spline IK chain. The twist
manipulators on each end of the chain show the
degree of twist.
Twi st St art A n g le —Sets the twist angle for the entire
chain, rotating all bones in the chain.
Twi st En d An g le —Sets the twist angle for the end
jointrelativetothestartjoint,creatingagradual
twist over the entire chain.
Pick Upnode—When Spline IK is assigned to a
bone chain, the IK system attempts to determine
the “up” direction for bones, which is the direction
in which the bones’ back fins should point. The
Spline IK Solver might interpret this direction
incorrectly, causing bones to flip to one side or
the other. Picking an upnode causes the “up”
direction to point along the picked object’s local
Z axis. By default, the upnode is set to the first
helper/knot on the spline, which usually causes the
“up” direction to be interpreted correctly.
Use—Use the picked node to specify the “up”
direction for the root bone.