Pin Rope Physics Motor


Pin Rope Physics Motor runs a connected chain of bones simulating a directible rope. The user has direct control of the end point of the rope.

Installation Requirements

This motor requires 2 or more connected consecutive bones to be installed.


Pin Rope Physics Motor defines a simulated chain of bones with forces between them both trying to preserve length and the overall shape of the curve along the bones.

The user sets the stiffness property to a high value if the overall shape of the curve needs to be preserved under motion. Lowering stiffness to 0 results in a free flowing material like rope or cloth. stretchStiffness allows the user to tweak how stretchy the material is.

If the simulation is unstable or jittery, remember to increase the damping value. This makes the motion bleed energy faster and will result in more stability under high amounts of motion.

The final bone of the rope follows the target point set by the user. This drags the rest of the rope along, making the motor useful as a directible rope object(reins, straps etc.)

Animatable Properties

  • stiffness This determines how much of the curve's shape is preserved during simulation. (Values to try: 10 to 100)

  • stretchStiffness This determines how stretchy the material is. (Values to try: 10 to 150)

  • damping This determines how quickly energy bleeds from the system. (Values to try: 1 to 80)

  • gravityFactor This determines the amount of gravity pulling on the simulated bones. Set this value to 0 if you do not want any gravitational effects. (Values to try: 0 to 3)

  • fadeStiffnessRatio This determines how the stiffness value fades over the affected bone elements. You typically do not need to adjust this value.

  • pinX This determines the x target point of the rope.

  • pinY This determines the y target point of the rope.

Static Properties