Digital Marionette

# Passive Rider Animation
copyright 2023 Michael Lastufka

## Marionette style control points in external source's coordinates:
* All measurements are in inches and degrees.
* Frame coords x="+fore -back" y="+left -right" z="+up - down"

## Hand/Feet Target points provided by external source:
handL, handR, footL, footR
## Posture provided by external source:
cm: Center of mass point (between spine and hips)
spineAxis: Spine Axis vector or unit vector passing through cm
## Controls:
Shoulder and hip rotation: spinS, spinH
## Main module:
Rider(handL, handR, footL, footR, cm, spineAxis, spinS, spinH)

## Support modules:
`JointedAppendage(bodyAttachment, medialLen, distalLen, freeEnd, splay, label="Appendage", orient)`
`CylinderSpan(origin, endPt, radius)`

## Support functions:
`ShoulderSocket(side, spinS, tiltAxis, tiltAng)`
`JointPos(bodyAttachment, medialLen, distalLen, freeEnd, splay, orient)`
`Rot