I have set the margin-top by css for tag canvas that contains my 3d shape and now the raycaster doesn't work fine. I used raycaster intersection to drag the shape and now you can drag the shape also if you are not perfectly on it but little above.You can see live example here: http://www.felpone.netsons.org/web-threejs/stereos%20-%20Copia.html
#ThreeJS canvas {
margin-top: 50px;
}
Another way may be to delete margin and able the top menu to stay up canvas tag for example with z-index but doesn't work.