Here are the additional
controls for the HI IK solver. The IK Solver Plane is controlled
here through the Swivel Angle, which can be animated directly or
using a target object.
In the Parent Space group
you can choose to whether the IK goal or the start joint will be
used as the parent space for the swivel angle. If IK Goal is selected
(which is the default), then the Swivel Angle of the chain is defined
in the parent space of its goal. If Start Joint is chosen, then
the Swivel Angle will be relative to the parent space of the start
joint. These two options allow a much better control of the swivel
angle on a chain with two HI IK solvers. For example, the first
solver on the upper part of a chain can use a Swivel Angle in the
Parent Space of the Start Joint, while the second IK solver on the
lower part of the chain uses the Parent Space of the IK Goal. In
this case, the change of the Swivel Angle for one chain won’t change
the orientation of the other one.
In the Thresholds and
Solutions group you can refine the IK solution. The Position Threshold
sets a limit in units of how far the goal can be moved from the
end effector, the Rotation does the same in angle degrees.
The Solutions group Iterations
is the maximum number of attempts the IK solution will perform before
If your IK animation
seems to jitter, try increasing the Iterations to 200. Increasing
the Iterations will slow down the computational time, but should
produce better results.
Manipulator for the Swivel
can adjust the swivel angle with the spinner in this rollout, or
you can adjust it with a manipulator. To do so, turn on
and Manipulate. The swivel angle manipulator
is displayed as a handle in the viewports.
Swivel angle manipulator.
Swivel angle manipulator.
When you move the mouse
over the manipulator, it turns red. At this point, you can drag
the manipulator to change the swivel angle. The Auto Key button
can be active while you do this.
You can also animate
the swivel angle by using a target object. Pick an object for the
target, then animating the object will animate the swivel angle.
The swivel angle manipulator
is a standard
angle manipulator. The HI Solver has its
own controls for displaying this manipulator. These are on the
Display Options rollout.
To increase the precision of an IK solution:
the goal in an HI IK chain.
- In the IK Solver Properties rollout increase
the Iterations to 200 in the solutions group.
- You can also adjust the Position and
Rotation Thresholds to a smaller value.
IK Solver Plane group
- Swivel Angle
Controls the Solver Plane which
determines the direction of the knee or elbow in a human limb. The
Swivel Angle can be manipulated in the viewport by turning on Swivel
Angle Display in the Display Options rollout, and then turning on
Manipulate Mode. When the swivel angle manipulator is displayed in
the viewport, you can interactively animate the handle to animate
the solver plane.
- Pick Target
Lets you select another object
to use to animate the Swivel Angle.
Turns the use of the Target
on and off.
- Parent Space
Defines what space the Swivel
Angle is relative to. Use this on chains with multiple solvers,
so the swivel angle manipulations on one chain will not affect the second.
For more information, see
White Paper: Swivel Angle of the HI IK Solver.
- IK Goal
Defines the Swivel Angle parent
space relative to the IK Goal.
- Start Joint
Defines the Swivel Angle Parent
Space relative to the Start Joint.
Use to define the tolerances
the system uses for its calculations.
Sets a limit in units
of how far the goal can be moved from the end effector. Keep these
Sets a limit in degrees
of how far the goal can be rotated away from the end effector rotation.
Keep these numbers low for best results.
Note that adjusting the
Rotation threshold on the HI Solver and IK Limb Solver has no effect.
It is up to the plug-in solver’s discretion as to whether or not
they will support a rotation component in the IK solution.
Use to control the precision
of the animation. Increase the iterations when the IK solution produces
an animation that appears rough or jittered.
The number of attempts an
IK solution will make to find the best match between the goal and
the end effector positions. Increase this number if you are seeing