[Vectrosity] 3d bezier curve not generated correctly

Hello,

I'm trying to draw a 3D bezier curve with Vectrosity (in order to create a 3D selection arrow). If the curve is aligned with the Y-axis, then the result looks as expected (red curve), but any other alignment makes the segments of the curve visible and also introduces some glitches at the start and the end (black curve). Any idea why is this happening?

 // Black curve (bad).
 VectorLine vl = new VectorLine( 
     "vl0", 
     new List<Vector3>() { Vector3.zero, Vector3.zero }, 
     30.0f);
 vl.lineType = LineType.Continuous;
 vl.Resize( 111 );
 vl.MakeCurve( 
     Vector3.zero, 
     new Vector3( .0f, .0f, -1.0f ),
     new Vector3( -3.0f, .0f, .0f ),
     new Vector3( -3.0f, .0f, -1.0f ),
     110 );
 vl.Draw3D();
 vl.color = Color.black;
     
 // Red curve (good!).
 vl = new VectorLine(
     "vl1", 
     new List<Vector3>() { Vector3.zero, Vector3.zero }, 
     30.0f);
 vl.lineType = LineType.Continuous;
 vl.Resize( 111 );
 vl.MakeCurve( 
     Vector3.zero, 
     new Vector3( .0f, .0f, -1.0f ),
     new Vector3( .0f, 3.0f, .0f ),
     new Vector3( .0f, 3.0f, -1.0f ),
     110 );
 vl.Draw3D();
 vl.color = Color.red;