The FootPlatform is
the IK target for the feet. Its motion is critical to the animation
of the legs.
A CATRig’s FootPlatform
has an animated pivot position to make sure that the foot always
rotates around the correct point. The RollPivotPos controller determines
the position of the pivot across the X axis of the FootPlatform
(or from one side to the other).
A value of 1.0 represents
the outside of the foot and a value of 0.0 the inside of the foot
Note You can animate
this setting, but it is usually kept constant throughout the cycle.
For a human, the normal value is 1.0.
The Roll controller controls
the rotation of the FootPlatform along its length.
In the following illustration,
the roll starts before the foot leaves the ground and ends after
the foot is on the ground. This is a typical scenario.
The FootPlatform has
an animated pivot position to make sure the foot always rotates
around the desired point. The PitchPivotPos controls the position
of the pivot along the Y axis of the FootPlatform; that is, along
A value of 0.0 positions
the pivot at the heel of the foot platform, and a value of 1.0 positions
the pivot at the toe.
For a human, this setting
typically animates between the toe (1.0) for lift and the heel (0.0)
for plant, as shown in the following illustration.
As with the standard
Pitch controller, FootPlatform Pitch controls the angle of the FootPlatform
along its length (Y axis). It is used to control the angle of the
foot as it lifts off and slaps down, as shown in the following illustration.
FootPush is a cyclic
positional offset along the Y axis that enables you to throw the
FootPlatform forward during the walk cycle.
The Swerve controller
is actually the same as the WeightShift controller. It controls
the side-to-side (X axis) positional cycle for the FootPlatform.
The StepShape controller
controls the velocity of the FootPlatform as it moves through the
air. In other words, it controls the ease-in and ease-out of the
will have bigger ease curves. Quick movement such as running will
have an almost linear StepShape curve.