ios - Binding SKShape node to the CGPathGetCurrentPoint -

I try to force SKShapeNode to force CGPathGetCurrentPoint of my circle. But it seems that the path is not going on.

  CGPind D ... myPath = CGPathCreateMutable (); CGPathAddArc (Mypet, NULL, 0,0, 60, 10, M_PI * 2, Yes); Arc = [SKShapeNode node]; Arc.path = myPath; ... [Add Child Child: Arc];  

Everything is fine here. Then I connect my ball to the arch

  ball = [SKShapeNode node]; Ball.path = Ballpath CGP; [Self linking child: ball]; ... d = CGPathGetCurrentPoint (arc.path); Ball.position = CP Point Make (DX, D.I.);  touched  in  

I placed the rotation code for my arc

  arc.zRotation + = angleRadians * 4; D = CGPathGetCurrentPoint (arc.path); Ball.position = CP Point Make (DX, D.I.);  

Nothing else happens I want the ball to rotate from the current point and proceed with it.