clamp-bend.cs

public static Vector3 ClampBend(Vector3 vector, Vector3 reference, float maxBendAngle)
{
  float vectorLenSqr = vector.sqrMagnitude;
  if (vectorLenSqr < MathUtil.Epsilon)
    return vector;

  float referenceLenSqr = reference.sqrMagnitude;
  if (referenceLenSqr < MathUtil.Epsilon)
    return vector;

  Quaternion bendRot = Quaternion.FromToRotation(reference, vector);
  Vector3 axis = QuaternionUtil.GetAxis(bendRot);
  float angle = QuaternionUtil.GetAngle(bendRot);
  if (angle > MathUtil.Pi)
  {
    axis = -axis;
    angle = MathUtil.TwoPi - angle;
  }

  if (angle <= maxBendAngle)
    return vector;

  Quaternion clampedBendRot = QuaternionUtil.AxisAngle(axis, maxBendAngle);
  Vector3 result = clampedBendRot * reference;
  result *= Mathf.Sqrt(vectorLenSqr) / Mathf.Sqrt(referenceLenSqr);

  return result;
}