Pole Vectors: Working with Pole Vectors

• Useful features to exploit:

  • Choice of reference frames
  • Physical location good for pseudo-IK behavior
    • Elbows, knees when crawling

• Drawbacks:

  • 3 DOF for a 1-dimensional idea
  • Behavior hard to predict
  • Overlap between PV control and twist

• Alternative uses:

  • Use with 1-link IK's as explicit aim constraint
  • “Target & Rollâ€? controls

• Pole vectors vs. twist paramters:

  • Use PV when limb's range of motion is more than 180Ëš
  • Use PV to control exact location of middle joints
  • Use twist when range of motion is limited
  • Use twist when the limb is locked in place