CubicCurve acceleration vector changes direction unexpectedly

[kybarg]

Not sure, but seems like an issue to me.

So i use CubicCardinalSpline on about 200 points, and at spline points acceleration vector unexpectedly changes its direction.

I expect that change shpuld be smooth along the whole spline.

    let path: CubicCurve<Vec3> = CubicCardinalSpline::new_catmull_rom(points.as_slice()).to_curve();

for ((position, velocity), acceleration) in road
   .path
   .iter_positions(sections)
   .zip(road.path.iter_velocities(sections))
   .zip(road.path.iter_accelerations(sections))
{
   gizmos.ray(position, acceleration.normalize(), Color::CYAN);
   gizmos.ray(position, velocity.normalize(), Color::RED);
   gizmos.ray(
       position,
       acceleration.cross(velocity).normalize(),
       Color::GREEN,
   );
}

[kybarg]

Sorry, haven't noticed it only has C1 continuity.