IK Rotate Motor

IK Rotate Motor

Overview

IK Rotate Motor allows the user to animate bones using an Inverse Kinematics Scheme. The target point is rotated around an ellipsoidal arc centered around a selected point.

Installation Requirements

This motor requires at least 2 consecutive connected bones to be installed.

Usage

Inverse Kinematics allows the user to specify a target point for a group of consecutively connected bones. The chain of bones with the IK Rotate Motor installed will pose automatically by following the ellipsoidal arc centered at a user defined point.

This motor is very useful for automating the animation of limbs, making it a powerful tool for walk cycles.

To simulate the ground contact on a flat plane, the user typically sets the scaleBottom property to 0. This flattens out the bottom part of the ellipsoidal arc, making the animated target point trace a flat motion before it arches upwards to complete the upper part of the ellipsoid.

The user will set the phase property to be different from another IK Rotate Motor by a difference of 2 to simulate alternate walking limbs in a walk cycle.

Applying the IK Rotate Motor onto more than 2 bones might result in jittery animation depending on how quickly the target point is changed over time. This motor allows for more degrees of freedom for the affected bone chain at the cost of stability. If a stable animation is desired, use the Smooth IK Rotate Motor instead.

Animatable Properties

  • targetX This determines the x position of the target point.

  • targetY This determines the y position of the target point.

  • speed This determines how quickly the target point rotates around the ellipsoidal arc. Typical values are 0.5 to 3.0. Set a negative value if you want the motion to be in reverse. (Values to try: 0.1 to 5)

  • phase This determines what the initial position of the target point is on the ellipsoidal arc. (Values to try: 0 to 3)

  • width This determines the overall width of the ellipsoidal arc.

  • height This determines the overall height of the ellipsoidal arc.

  • scaleLeft This scales the left half of the ellipsoidal arc by a factor. For example, setting it to 2.0 will scale that portion by two times. (Values to try: 0 to 3)

  • scaleRight This scales the right half of the ellipsoidal arc by a factor. For example, setting it to 2.0 will scale that portion by two times. (Values to try: 0 to 3)

  • scaleTop This scales the top half of the ellipsoidal arc by a factor. For example, setting it to 2.0 will scale that portion by two times. (Values to try: 0 to 3)

  • scaleBottom This scales the lower half of the ellipsoidal arc by a factor. For example, setting it to 2.0 will scale that portion by two times. (Values to try: 0 to 3)

Static Properties

  • Valid IK Angles This will limit the range of angles the chain of affected bones are allowed to pose with. You can select negative, positive or none.